app/django/template/__init__.py
author Todd Larsen <tlarsen@google.com>
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This CSS change belonged with soc/templates/soc/error.html committed in r454. Patch by: Todd Larsen Review by: to-be-reviewed
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"""
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This is the Django template system.
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How it works:
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The Lexer.tokenize() function converts a template string (i.e., a string containing
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markup with custom template tags) to tokens, which can be either plain text
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(TOKEN_TEXT), variables (TOKEN_VAR) or block statements (TOKEN_BLOCK).
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The Parser() class takes a list of tokens in its constructor, and its parse()
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method returns a compiled template -- which is, under the hood, a list of
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Node objects.
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Each Node is responsible for creating some sort of output -- e.g. simple text
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(TextNode), variable values in a given context (VariableNode), results of basic
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logic (IfNode), results of looping (ForNode), or anything else. The core Node
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types are TextNode, VariableNode, IfNode and ForNode, but plugin modules can
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define their own custom node types.
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Each Node has a render() method, which takes a Context and returns a string of
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the rendered node. For example, the render() method of a Variable Node returns
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the variable's value as a string. The render() method of an IfNode returns the
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rendered output of whatever was inside the loop, recursively.
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The Template class is a convenient wrapper that takes care of template
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compilation and rendering.
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Usage:
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The only thing you should ever use directly in this file is the Template class.
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Create a compiled template object with a template_string, then call render()
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with a context. In the compilation stage, the TemplateSyntaxError exception
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will be raised if the template doesn't have proper syntax.
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Sample code:
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>>> from django import template
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>>> s = u'<html>{% if test %}<h1>{{ varvalue }}</h1>{% endif %}</html>'
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>>> t = template.Template(s)
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(t is now a compiled template, and its render() method can be called multiple
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times with multiple contexts)
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>>> c = template.Context({'test':True, 'varvalue': 'Hello'})
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>>> t.render(c)
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u'<html><h1>Hello</h1></html>'
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>>> c = template.Context({'test':False, 'varvalue': 'Hello'})
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>>> t.render(c)
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u'<html></html>'
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"""
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import re
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from inspect import getargspec
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from django.conf import settings
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from django.template.context import Context, RequestContext, ContextPopException
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from django.utils.itercompat import is_iterable
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from django.utils.functional import curry, Promise
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from django.utils.text import smart_split
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from django.utils.encoding import smart_unicode, force_unicode
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from django.utils.translation import ugettext as _
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from django.utils.safestring import SafeData, EscapeData, mark_safe, mark_for_escaping
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from django.utils.html import escape
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__all__ = ('Template', 'Context', 'RequestContext', 'compile_string')
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TOKEN_TEXT = 0
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TOKEN_VAR = 1
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TOKEN_BLOCK = 2
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TOKEN_COMMENT = 3
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# template syntax constants
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FILTER_SEPARATOR = '|'
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FILTER_ARGUMENT_SEPARATOR = ':'
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VARIABLE_ATTRIBUTE_SEPARATOR = '.'
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BLOCK_TAG_START = '{%'
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BLOCK_TAG_END = '%}'
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VARIABLE_TAG_START = '{{'
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VARIABLE_TAG_END = '}}'
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COMMENT_TAG_START = '{#'
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COMMENT_TAG_END = '#}'
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SINGLE_BRACE_START = '{'
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SINGLE_BRACE_END = '}'
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ALLOWED_VARIABLE_CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.'
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# what to report as the origin for templates that come from non-loader sources
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# (e.g. strings)
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UNKNOWN_SOURCE="&lt;unknown source&gt;"
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# match a variable or block tag and capture the entire tag, including start/end delimiters
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tag_re = re.compile('(%s.*?%s|%s.*?%s|%s.*?%s)' % (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END),
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                                          re.escape(VARIABLE_TAG_START), re.escape(VARIABLE_TAG_END),
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                                          re.escape(COMMENT_TAG_START), re.escape(COMMENT_TAG_END)))
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# global dictionary of libraries that have been loaded using get_library
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libraries = {}
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# global list of libraries to load by default for a new parser
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builtins = []
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# True if TEMPLATE_STRING_IF_INVALID contains a format string (%s). None means
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# uninitialised.
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invalid_var_format_string = None
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class TemplateSyntaxError(Exception):
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    def __str__(self):
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        try:
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            import cStringIO as StringIO
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        except ImportError:
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            import StringIO
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        output = StringIO.StringIO()
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        output.write(Exception.__str__(self))
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        # Check if we wrapped an exception and print that too.
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        if hasattr(self, 'exc_info'):
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            import traceback
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            output.write('\n\nOriginal ')
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            e = self.exc_info
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            traceback.print_exception(e[0], e[1], e[2], 500, output)
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        return output.getvalue()
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class TemplateDoesNotExist(Exception):
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    pass
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class TemplateEncodingError(Exception):
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    pass
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class VariableDoesNotExist(Exception):
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    def __init__(self, msg, params=()):
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        self.msg = msg
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        self.params = params
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    def __str__(self):
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        return unicode(self).encode('utf-8')
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    def __unicode__(self):
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        return self.msg % tuple([force_unicode(p, errors='replace') for p in self.params])
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class InvalidTemplateLibrary(Exception):
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    pass
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class Origin(object):
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    def __init__(self, name):
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        self.name = name
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    def reload(self):
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        raise NotImplementedError
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    def __str__(self):
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        return self.name
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class StringOrigin(Origin):
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    def __init__(self, source):
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        super(StringOrigin, self).__init__(UNKNOWN_SOURCE)
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        self.source = source
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    def reload(self):
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        return self.source
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class Template(object):
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    def __init__(self, template_string, origin=None, name='<Unknown Template>'):
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        try:
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            template_string = smart_unicode(template_string)
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        except UnicodeDecodeError:
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            raise TemplateEncodingError("Templates can only be constructed from unicode or UTF-8 strings.")
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        if settings.TEMPLATE_DEBUG and origin is None:
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            origin = StringOrigin(template_string)
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        self.nodelist = compile_string(template_string, origin)
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        self.name = name
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    def __iter__(self):
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        for node in self.nodelist:
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            for subnode in node:
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                yield subnode
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    def render(self, context):
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        "Display stage -- can be called many times"
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        return self.nodelist.render(context)
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def compile_string(template_string, origin):
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    "Compiles template_string into NodeList ready for rendering"
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    if settings.TEMPLATE_DEBUG:
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        from debug import DebugLexer, DebugParser
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        lexer_class, parser_class = DebugLexer, DebugParser
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    else:
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        lexer_class, parser_class = Lexer, Parser
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    lexer = lexer_class(template_string, origin)
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    parser = parser_class(lexer.tokenize())
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    return parser.parse()
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class Token(object):
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    def __init__(self, token_type, contents):
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        # token_type must be TOKEN_TEXT, TOKEN_VAR, TOKEN_BLOCK or TOKEN_COMMENT.
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        self.token_type, self.contents = token_type, contents
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    def __str__(self):
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        return '<%s token: "%s...">' % \
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            ({TOKEN_TEXT: 'Text', TOKEN_VAR: 'Var', TOKEN_BLOCK: 'Block', TOKEN_COMMENT: 'Comment'}[self.token_type],
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            self.contents[:20].replace('\n', ''))
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    def split_contents(self):
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        return list(smart_split(self.contents))
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class Lexer(object):
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    def __init__(self, template_string, origin):
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        self.template_string = template_string
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        self.origin = origin
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    def tokenize(self):
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        "Return a list of tokens from a given template_string."
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        in_tag = False
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        result = []
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        for bit in tag_re.split(self.template_string):
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            if bit:
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                result.append(self.create_token(bit, in_tag))
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            in_tag = not in_tag
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        return result
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    def create_token(self, token_string, in_tag):
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        """
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        Convert the given token string into a new Token object and return it.
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        If in_tag is True, we are processing something that matched a tag,
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        otherwise it should be treated as a literal string.
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        """
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        if in_tag:
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            if token_string.startswith(VARIABLE_TAG_START):
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                token = Token(TOKEN_VAR, token_string[len(VARIABLE_TAG_START):-len(VARIABLE_TAG_END)].strip())
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            elif token_string.startswith(BLOCK_TAG_START):
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                token = Token(TOKEN_BLOCK, token_string[len(BLOCK_TAG_START):-len(BLOCK_TAG_END)].strip())
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            elif token_string.startswith(COMMENT_TAG_START):
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                token = Token(TOKEN_COMMENT, '')
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        else:
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            token = Token(TOKEN_TEXT, token_string)
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        return token
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class Parser(object):
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    def __init__(self, tokens):
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        self.tokens = tokens
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        self.tags = {}
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        self.filters = {}
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        for lib in builtins:
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            self.add_library(lib)
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    def parse(self, parse_until=None):
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        if parse_until is None: parse_until = []
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        nodelist = self.create_nodelist()
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        while self.tokens:
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            token = self.next_token()
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            if token.token_type == TOKEN_TEXT:
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                self.extend_nodelist(nodelist, TextNode(token.contents), token)
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            elif token.token_type == TOKEN_VAR:
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                if not token.contents:
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                    self.empty_variable(token)
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                filter_expression = self.compile_filter(token.contents)
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                var_node = self.create_variable_node(filter_expression)
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                self.extend_nodelist(nodelist, var_node,token)
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            elif token.token_type == TOKEN_BLOCK:
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                if token.contents in parse_until:
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                    # put token back on token list so calling code knows why it terminated
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                    self.prepend_token(token)
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                    return nodelist
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                try:
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   261
                    command = token.contents.split()[0]
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   262
                except IndexError:
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   263
                    self.empty_block_tag(token)
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                # execute callback function for this tag and append resulting node
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   265
                self.enter_command(command, token)
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   266
                try:
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   267
                    compile_func = self.tags[command]
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   268
                except KeyError:
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   269
                    self.invalid_block_tag(token, command)
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   270
                try:
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                    compiled_result = compile_func(self, token)
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                except TemplateSyntaxError, e:
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   273
                    if not self.compile_function_error(token, e):
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                        raise
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                self.extend_nodelist(nodelist, compiled_result, token)
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   276
                self.exit_command()
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   277
        if parse_until:
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   278
            self.unclosed_block_tag(parse_until)
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   279
        return nodelist
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   280
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    def skip_past(self, endtag):
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   282
        while self.tokens:
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   283
            token = self.next_token()
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   284
            if token.token_type == TOKEN_BLOCK and token.contents == endtag:
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                return
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   286
        self.unclosed_block_tag([endtag])
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   287
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   288
    def create_variable_node(self, filter_expression):
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   289
        return VariableNode(filter_expression)
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   290
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   291
    def create_nodelist(self):
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   292
        return NodeList()
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   293
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   294
    def extend_nodelist(self, nodelist, node, token):
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   295
        if node.must_be_first and nodelist:
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   296
            try:
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   297
                if nodelist.contains_nontext:
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   298
                    raise AttributeError
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   299
            except AttributeError:
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   300
                raise TemplateSyntaxError("%r must be the first tag in the template." % node)
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   301
        if isinstance(nodelist, NodeList) and not isinstance(node, TextNode):
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   302
            nodelist.contains_nontext = True
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   303
        nodelist.append(node)
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   304
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   305
    def enter_command(self, command, token):
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   306
        pass
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   307
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   308
    def exit_command(self):
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   309
        pass
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   310
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   311
    def error(self, token, msg):
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   312
        return TemplateSyntaxError(msg)
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   313
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   314
    def empty_variable(self, token):
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   315
        raise self.error(token, "Empty variable tag")
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   316
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   317
    def empty_block_tag(self, token):
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   318
        raise self.error(token, "Empty block tag")
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   319
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   320
    def invalid_block_tag(self, token, command):
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diff changeset
   321
        raise self.error(token, "Invalid block tag: '%s'" % command)
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   322
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   323
    def unclosed_block_tag(self, parse_until):
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diff changeset
   324
        raise self.error(None, "Unclosed tags: %s " %  ', '.join(parse_until))
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   325
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   326
    def compile_function_error(self, token, e):
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   327
        pass
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   328
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   329
    def next_token(self):
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diff changeset
   330
        return self.tokens.pop(0)
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diff changeset
   331
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   332
    def prepend_token(self, token):
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diff changeset
   333
        self.tokens.insert(0, token)
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diff changeset
   334
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   335
    def delete_first_token(self):
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parents:
diff changeset
   336
        del self.tokens[0]
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parents:
diff changeset
   337
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   338
    def add_library(self, lib):
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diff changeset
   339
        self.tags.update(lib.tags)
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parents:
diff changeset
   340
        self.filters.update(lib.filters)
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diff changeset
   341
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diff changeset
   342
    def compile_filter(self, token):
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parents:
diff changeset
   343
        "Convenient wrapper for FilterExpression"
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parents:
diff changeset
   344
        return FilterExpression(token, self)
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diff changeset
   345
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diff changeset
   346
    def find_filter(self, filter_name):
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parents:
diff changeset
   347
        if filter_name in self.filters:
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parents:
diff changeset
   348
            return self.filters[filter_name]
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diff changeset
   349
        else:
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diff changeset
   350
            raise TemplateSyntaxError("Invalid filter: '%s'" % filter_name)
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   351
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   352
class TokenParser(object):
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   353
    """
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parents:
diff changeset
   354
    Subclass this and implement the top() method to parse a template line. When
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   355
    instantiating the parser, pass in the line from the Django template parser.
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diff changeset
   356
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   357
    The parser's "tagname" instance-variable stores the name of the tag that
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   358
    the filter was called with.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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diff changeset
   359
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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diff changeset
   360
    def __init__(self, subject):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   361
        self.subject = subject
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   362
        self.pointer = 0
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   363
        self.backout = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   364
        self.tagname = self.tag()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   365
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   366
    def top(self):
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parents:
diff changeset
   367
        "Overload this method to do the actual parsing and return the result."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   368
        raise NotImplementedError()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   369
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   370
    def more(self):
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parents:
diff changeset
   371
        "Returns True if there is more stuff in the tag."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   372
        return self.pointer < len(self.subject)
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parents:
diff changeset
   373
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   374
    def back(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   375
        "Undoes the last microparser. Use this for lookahead and backtracking."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   376
        if not len(self.backout):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   377
            raise TemplateSyntaxError("back called without some previous parsing")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   378
        self.pointer = self.backout.pop()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   379
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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diff changeset
   380
    def tag(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   381
        "A microparser that just returns the next tag from the line."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
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parents:
diff changeset
   382
        subject = self.subject
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   383
        i = self.pointer
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   384
        if i >= len(subject):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   385
            raise TemplateSyntaxError("expected another tag, found end of string: %s" % subject)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   386
        p = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   387
        while i < len(subject) and subject[i] not in (' ', '\t'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   388
            i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   389
        s = subject[p:i]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   390
        while i < len(subject) and subject[i] in (' ', '\t'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   391
            i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   392
        self.backout.append(self.pointer)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   393
        self.pointer = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   394
        return s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   395
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   396
    def value(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   397
        "A microparser that parses for a value: some string constant or variable name."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   398
        subject = self.subject
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   399
        i = self.pointer
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   400
        if i >= len(subject):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   401
            raise TemplateSyntaxError("Searching for value. Expected another value but found end of string: %s" % subject)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   402
        if subject[i] in ('"', "'"):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   403
            p = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   404
            i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   405
            while i < len(subject) and subject[i] != subject[p]:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   406
                i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   407
            if i >= len(subject):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   408
                raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   409
            i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   410
            res = subject[p:i]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   411
            while i < len(subject) and subject[i] in (' ', '\t'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   412
                i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   413
            self.backout.append(self.pointer)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   414
            self.pointer = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   415
            return res
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   416
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   417
            p = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   418
            while i < len(subject) and subject[i] not in (' ', '\t'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   419
                if subject[i] in ('"', "'"):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   420
                    c = subject[i]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   421
                    i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   422
                    while i < len(subject) and subject[i] != c:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   423
                        i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   424
                    if i >= len(subject):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   425
                        raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   426
                i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   427
            s = subject[p:i]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   428
            while i < len(subject) and subject[i] in (' ', '\t'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   429
                i += 1
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   430
            self.backout.append(self.pointer)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   431
            self.pointer = i
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   432
            return s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   433
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   434
filter_raw_string = r"""
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   435
^%(i18n_open)s"(?P<i18n_constant>%(str)s)"%(i18n_close)s|
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   436
^"(?P<constant>%(str)s)"|
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   437
^(?P<var>[%(var_chars)s]+)|
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   438
 (?:%(filter_sep)s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   439
     (?P<filter_name>\w+)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   440
         (?:%(arg_sep)s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   441
             (?:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   442
              %(i18n_open)s"(?P<i18n_arg>%(str)s)"%(i18n_close)s|
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   443
              "(?P<constant_arg>%(str)s)"|
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   444
              (?P<var_arg>[%(var_chars)s]+)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   445
             )
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   446
         )?
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   447
 )""" % {
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   448
    'str': r"""[^"\\]*(?:\\.[^"\\]*)*""",
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   449
    'var_chars': "\w\." ,
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   450
    'filter_sep': re.escape(FILTER_SEPARATOR),
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   451
    'arg_sep': re.escape(FILTER_ARGUMENT_SEPARATOR),
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   452
    'i18n_open' : re.escape("_("),
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   453
    'i18n_close' : re.escape(")"),
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   454
  }
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   455
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   456
filter_raw_string = filter_raw_string.replace("\n", "").replace(" ", "")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   457
filter_re = re.compile(filter_raw_string, re.UNICODE)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   458
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   459
class FilterExpression(object):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   460
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   461
    Parses a variable token and its optional filters (all as a single string),
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   462
    and return a list of tuples of the filter name and arguments.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   463
    Sample:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   464
        >>> token = 'variable|default:"Default value"|date:"Y-m-d"'
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   465
        >>> p = Parser('')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   466
        >>> fe = FilterExpression(token, p)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   467
        >>> len(fe.filters)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   468
        2
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   469
        >>> fe.var
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   470
        'variable'
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   471
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   472
    This class should never be instantiated outside of the
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   473
    get_filters_from_token helper function.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   474
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   475
    def __init__(self, token, parser):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   476
        self.token = token
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   477
        matches = filter_re.finditer(token)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   478
        var = None
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   479
        filters = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   480
        upto = 0
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   481
        for match in matches:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   482
            start = match.start()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   483
            if upto != start:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   484
                raise TemplateSyntaxError("Could not parse some characters: %s|%s|%s"  % \
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   485
                                           (token[:upto], token[upto:start], token[start:]))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   486
            if var == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   487
                var, constant, i18n_constant = match.group("var", "constant", "i18n_constant")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   488
                if i18n_constant:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   489
                    var = '"%s"' %  _(i18n_constant.replace(r'\"', '"'))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   490
                elif constant:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   491
                    var = '"%s"' % constant.replace(r'\"', '"')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   492
                upto = match.end()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   493
                if var == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   494
                    raise TemplateSyntaxError("Could not find variable at start of %s" % token)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   495
                elif var.find(VARIABLE_ATTRIBUTE_SEPARATOR + '_') > -1 or var[0] == '_':
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   496
                    raise TemplateSyntaxError("Variables and attributes may not begin with underscores: '%s'" % var)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   497
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   498
                filter_name = match.group("filter_name")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   499
                args = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   500
                constant_arg, i18n_arg, var_arg = match.group("constant_arg", "i18n_arg", "var_arg")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   501
                if i18n_arg:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   502
                    args.append((False, _(i18n_arg.replace(r'\"', '"'))))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   503
                elif constant_arg is not None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   504
                    args.append((False, constant_arg.replace(r'\"', '"')))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   505
                elif var_arg:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   506
                    args.append((True, Variable(var_arg)))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   507
                filter_func = parser.find_filter(filter_name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   508
                self.args_check(filter_name,filter_func, args)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   509
                filters.append( (filter_func,args))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   510
                upto = match.end()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   511
        if upto != len(token):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   512
            raise TemplateSyntaxError("Could not parse the remainder: '%s' from '%s'" % (token[upto:], token))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   513
        self.filters = filters
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   514
        self.var = Variable(var)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   515
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   516
    def resolve(self, context, ignore_failures=False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   517
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   518
            obj = self.var.resolve(context)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   519
        except VariableDoesNotExist:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   520
            if ignore_failures:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   521
                obj = None
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   522
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   523
                if settings.TEMPLATE_STRING_IF_INVALID:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   524
                    global invalid_var_format_string
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   525
                    if invalid_var_format_string is None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   526
                        invalid_var_format_string = '%s' in settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   527
                    if invalid_var_format_string:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   528
                        return settings.TEMPLATE_STRING_IF_INVALID % self.var
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   529
                    return settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   530
                else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   531
                    obj = settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   532
        for func, args in self.filters:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   533
            arg_vals = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   534
            for lookup, arg in args:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   535
                if not lookup:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   536
                    arg_vals.append(mark_safe(arg))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   537
                else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   538
                    arg_vals.append(arg.resolve(context))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   539
            if getattr(func, 'needs_autoescape', False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   540
                new_obj = func(obj, autoescape=context.autoescape, *arg_vals)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   541
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   542
                new_obj = func(obj, *arg_vals)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   543
            if getattr(func, 'is_safe', False) and isinstance(obj, SafeData):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   544
                obj = mark_safe(new_obj)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   545
            elif isinstance(obj, EscapeData):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   546
                obj = mark_for_escaping(new_obj)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   547
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   548
                obj = new_obj
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   549
        return obj
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   550
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   551
    def args_check(name, func, provided):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   552
        provided = list(provided)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   553
        plen = len(provided)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   554
        # Check to see if a decorator is providing the real function.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   555
        func = getattr(func, '_decorated_function', func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   556
        args, varargs, varkw, defaults = getargspec(func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   557
        # First argument is filter input.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   558
        args.pop(0)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   559
        if defaults:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   560
            nondefs = args[:-len(defaults)]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   561
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   562
            nondefs = args
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   563
        # Args without defaults must be provided.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   564
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   565
            for arg in nondefs:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   566
                provided.pop(0)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   567
        except IndexError:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   568
            # Not enough
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   569
            raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   570
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   571
        # Defaults can be overridden.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   572
        defaults = defaults and list(defaults) or []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   573
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   574
            for parg in provided:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   575
                defaults.pop(0)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   576
        except IndexError:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   577
            # Too many.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   578
            raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   579
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   580
        return True
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   581
    args_check = staticmethod(args_check)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   582
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   583
    def __str__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   584
        return self.token
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   585
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   586
def resolve_variable(path, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   587
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   588
    Returns the resolved variable, which may contain attribute syntax, within
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   589
    the given context.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   590
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   591
    Deprecated; use the Variable class instead.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   592
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   593
    return Variable(path).resolve(context)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   594
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   595
class Variable(object):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   596
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   597
    A template variable, resolvable against a given context. The variable may be
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   598
    a hard-coded string (if it begins and ends with single or double quote
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   599
    marks)::
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   600
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   601
        >>> c = {'article': {'section':'News'}}
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   602
        >>> Variable('article.section').resolve(c)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   603
        u'News'
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   604
        >>> Variable('article').resolve(c)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   605
        {'section': 'News'}
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   606
        >>> class AClass: pass
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   607
        >>> c = AClass()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   608
        >>> c.article = AClass()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   609
        >>> c.article.section = 'News'
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   610
        >>> Variable('article.section').resolve(c)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   611
        u'News'
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   612
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   613
    (The example assumes VARIABLE_ATTRIBUTE_SEPARATOR is '.')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   614
    """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   615
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   616
    def __init__(self, var):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   617
        self.var = var
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   618
        self.literal = None
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   619
        self.lookups = None
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   620
        self.translate = False
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   621
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   622
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   623
            # First try to treat this variable as a number.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   624
            #
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   625
            # Note that this could cause an OverflowError here that we're not
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   626
            # catching. Since this should only happen at compile time, that's
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   627
            # probably OK.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   628
            self.literal = float(var)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   629
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   630
            # So it's a float... is it an int? If the original value contained a
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   631
            # dot or an "e" then it was a float, not an int.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   632
            if '.' not in var and 'e' not in var.lower():
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   633
                self.literal = int(self.literal)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   634
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   635
            # "2." is invalid
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   636
            if var.endswith('.'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   637
                raise ValueError
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   638
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   639
        except ValueError:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   640
            # A ValueError means that the variable isn't a number.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   641
            if var.startswith('_(') and var.endswith(')'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   642
                # The result of the lookup should be translated at rendering
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   643
                # time.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   644
                self.translate = True
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   645
                var = var[2:-1]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   646
            # If it's wrapped with quotes (single or double), then
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   647
            # we're also dealing with a literal.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   648
            if var[0] in "\"'" and var[0] == var[-1]:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   649
                self.literal = mark_safe(var[1:-1])
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   650
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   651
                # Otherwise we'll set self.lookups so that resolve() knows we're
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   652
                # dealing with a bonafide variable
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   653
                self.lookups = tuple(var.split(VARIABLE_ATTRIBUTE_SEPARATOR))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   654
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   655
    def resolve(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   656
        """Resolve this variable against a given context."""
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   657
        if self.lookups is not None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   658
            # We're dealing with a variable that needs to be resolved
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   659
            value = self._resolve_lookup(context)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   660
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   661
            # We're dealing with a literal, so it's already been "resolved"
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   662
            value = self.literal
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   663
        if self.translate:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   664
            return _(value)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   665
        return value
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   666
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   667
    def __repr__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   668
        return "<%s: %r>" % (self.__class__.__name__, self.var)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   669
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   670
    def __str__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   671
        return self.var
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   672
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   673
    def _resolve_lookup(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   674
        """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   675
        Performs resolution of a real variable (i.e. not a literal) against the
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   676
        given context.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   677
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   678
        As indicated by the method's name, this method is an implementation
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   679
        detail and shouldn't be called by external code. Use Variable.resolve()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   680
        instead.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   681
        """
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   682
        current = context
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   683
        for bit in self.lookups:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   684
            try: # dictionary lookup
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   685
                current = current[bit]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   686
            except (TypeError, AttributeError, KeyError):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   687
                try: # attribute lookup
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   688
                    current = getattr(current, bit)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   689
                    if callable(current):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   690
                        if getattr(current, 'alters_data', False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   691
                            current = settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   692
                        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   693
                            try: # method call (assuming no args required)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   694
                                current = current()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   695
                            except TypeError: # arguments *were* required
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   696
                                # GOTCHA: This will also catch any TypeError
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   697
                                # raised in the function itself.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   698
                                current = settings.TEMPLATE_STRING_IF_INVALID # invalid method call
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   699
                            except Exception, e:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   700
                                if getattr(e, 'silent_variable_failure', False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   701
                                    current = settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   702
                                else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   703
                                    raise
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   704
                except (TypeError, AttributeError):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   705
                    try: # list-index lookup
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   706
                        current = current[int(bit)]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   707
                    except (IndexError, # list index out of range
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   708
                            ValueError, # invalid literal for int()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   709
                            KeyError,   # current is a dict without `int(bit)` key
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   710
                            TypeError,  # unsubscriptable object
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   711
                            ):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   712
                        raise VariableDoesNotExist("Failed lookup for key [%s] in %r", (bit, current)) # missing attribute
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   713
                except Exception, e:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   714
                    if getattr(e, 'silent_variable_failure', False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   715
                        current = settings.TEMPLATE_STRING_IF_INVALID
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   716
                    else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   717
                        raise
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   718
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   719
        return current
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   720
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   721
class Node(object):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   722
    # Set this to True for nodes that must be first in the template (although
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   723
    # they can be preceded by text nodes.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   724
    must_be_first = False
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   725
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   726
    def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   727
        "Return the node rendered as a string"
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   728
        pass
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   729
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   730
    def __iter__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   731
        yield self
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   732
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   733
    def get_nodes_by_type(self, nodetype):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   734
        "Return a list of all nodes (within this node and its nodelist) of the given type"
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   735
        nodes = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   736
        if isinstance(self, nodetype):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   737
            nodes.append(self)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   738
        if hasattr(self, 'nodelist'):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   739
            nodes.extend(self.nodelist.get_nodes_by_type(nodetype))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   740
        return nodes
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   741
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   742
class NodeList(list):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   743
    # Set to True the first time a non-TextNode is inserted by
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   744
    # extend_nodelist().
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   745
    contains_nontext = False
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   746
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   747
    def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   748
        bits = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   749
        for node in self:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   750
            if isinstance(node, Node):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   751
                bits.append(self.render_node(node, context))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   752
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   753
                bits.append(node)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   754
        return mark_safe(''.join([force_unicode(b) for b in bits]))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   755
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   756
    def get_nodes_by_type(self, nodetype):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   757
        "Return a list of all nodes of the given type"
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   758
        nodes = []
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   759
        for node in self:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   760
            nodes.extend(node.get_nodes_by_type(nodetype))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   761
        return nodes
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   762
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   763
    def render_node(self, node, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   764
        return node.render(context)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   765
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   766
class TextNode(Node):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   767
    def __init__(self, s):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   768
        self.s = s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   769
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   770
    def __repr__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   771
        return "<Text Node: '%s'>" % self.s[:25]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   772
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   773
    def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   774
        return self.s
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   775
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   776
class VariableNode(Node):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   777
    def __init__(self, filter_expression):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   778
        self.filter_expression = filter_expression
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   779
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   780
    def __repr__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   781
        return "<Variable Node: %s>" % self.filter_expression
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   782
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   783
    def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   784
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   785
            output = force_unicode(self.filter_expression.resolve(context))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   786
        except UnicodeDecodeError:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   787
            # Unicode conversion can fail sometimes for reasons out of our
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   788
            # control (e.g. exception rendering). In that case, we fail quietly.
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   789
            return ''
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   790
        if (context.autoescape and not isinstance(output, SafeData)) or isinstance(output, EscapeData):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   791
            return force_unicode(escape(output))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   792
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   793
            return force_unicode(output)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   794
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   795
def generic_tag_compiler(params, defaults, name, node_class, parser, token):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   796
    "Returns a template.Node subclass."
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   797
    bits = token.split_contents()[1:]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   798
    bmax = len(params)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   799
    def_len = defaults and len(defaults) or 0
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   800
    bmin = bmax - def_len
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   801
    if(len(bits) < bmin or len(bits) > bmax):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   802
        if bmin == bmax:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   803
            message = "%s takes %s arguments" % (name, bmin)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   804
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   805
            message = "%s takes between %s and %s arguments" % (name, bmin, bmax)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   806
        raise TemplateSyntaxError(message)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   807
    return node_class(bits)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   808
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   809
class Library(object):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   810
    def __init__(self):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   811
        self.filters = {}
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   812
        self.tags = {}
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   813
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   814
    def tag(self, name=None, compile_function=None):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   815
        if name == None and compile_function == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   816
            # @register.tag()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   817
            return self.tag_function
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   818
        elif name != None and compile_function == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   819
            if(callable(name)):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   820
                # @register.tag
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   821
                return self.tag_function(name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   822
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   823
                # @register.tag('somename') or @register.tag(name='somename')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   824
                def dec(func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   825
                    return self.tag(name, func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   826
                return dec
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   827
        elif name != None and compile_function != None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   828
            # register.tag('somename', somefunc)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   829
            self.tags[name] = compile_function
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   830
            return compile_function
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   831
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   832
            raise InvalidTemplateLibrary("Unsupported arguments to Library.tag: (%r, %r)", (name, compile_function))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   833
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   834
    def tag_function(self,func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   835
        self.tags[getattr(func, "_decorated_function", func).__name__] = func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   836
        return func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   837
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   838
    def filter(self, name=None, filter_func=None):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   839
        if name == None and filter_func == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   840
            # @register.filter()
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   841
            return self.filter_function
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   842
        elif filter_func == None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   843
            if(callable(name)):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   844
                # @register.filter
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   845
                return self.filter_function(name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   846
            else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   847
                # @register.filter('somename') or @register.filter(name='somename')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   848
                def dec(func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   849
                    return self.filter(name, func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   850
                return dec
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   851
        elif name != None and filter_func != None:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   852
            # register.filter('somename', somefunc)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   853
            self.filters[name] = filter_func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   854
            return filter_func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   855
        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   856
            raise InvalidTemplateLibrary("Unsupported arguments to Library.filter: (%r, %r)", (name, filter_func))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   857
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   858
    def filter_function(self, func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   859
        self.filters[getattr(func, "_decorated_function", func).__name__] = func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   860
        return func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   861
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   862
    def simple_tag(self,func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   863
        params, xx, xxx, defaults = getargspec(func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   864
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   865
        class SimpleNode(Node):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   866
            def __init__(self, vars_to_resolve):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   867
                self.vars_to_resolve = map(Variable, vars_to_resolve)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   868
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   869
            def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   870
                resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   871
                return func(*resolved_vars)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   872
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   873
        compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   874
        compile_func.__doc__ = func.__doc__
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   875
        self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   876
        return func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   877
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   878
    def inclusion_tag(self, file_name, context_class=Context, takes_context=False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   879
        def dec(func):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   880
            params, xx, xxx, defaults = getargspec(func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   881
            if takes_context:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   882
                if params[0] == 'context':
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   883
                    params = params[1:]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   884
                else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   885
                    raise TemplateSyntaxError("Any tag function decorated with takes_context=True must have a first argument of 'context'")
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   886
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   887
            class InclusionNode(Node):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   888
                def __init__(self, vars_to_resolve):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   889
                    self.vars_to_resolve = map(Variable, vars_to_resolve)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   890
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   891
                def render(self, context):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   892
                    resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   893
                    if takes_context:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   894
                        args = [context] + resolved_vars
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   895
                    else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   896
                        args = resolved_vars
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   897
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   898
                    dict = func(*args)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   899
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   900
                    if not getattr(self, 'nodelist', False):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   901
                        from django.template.loader import get_template, select_template
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   902
                        if not isinstance(file_name, basestring) and is_iterable(file_name):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   903
                            t = select_template(file_name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   904
                        else:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   905
                            t = get_template(file_name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   906
                        self.nodelist = t.nodelist
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   907
                    return self.nodelist.render(context_class(dict,
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   908
                            autoescape=context.autoescape))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   909
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   910
            compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, InclusionNode)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   911
            compile_func.__doc__ = func.__doc__
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   912
            self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   913
            return func
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   914
        return dec
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   915
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   916
def get_library(module_name):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   917
    lib = libraries.get(module_name, None)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   918
    if not lib:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   919
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   920
            mod = __import__(module_name, {}, {}, [''])
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   921
        except ImportError, e:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   922
            raise InvalidTemplateLibrary("Could not load template library from %s, %s" % (module_name, e))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   923
        try:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   924
            lib = mod.register
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   925
            libraries[module_name] = lib
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   926
        except AttributeError:
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   927
            raise InvalidTemplateLibrary("Template library %s does not have a variable named 'register'" % module_name)
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   928
    return lib
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   929
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   930
def add_to_builtins(module_name):
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   931
    builtins.append(get_library(module_name))
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   932
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   933
add_to_builtins('django.template.defaulttags')
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
   934
add_to_builtins('django.template.defaultfilters')