+
−from django.template import Lexer, Parser, tag_re, NodeList, VariableNode, TemplateSyntaxError
+
−from django.utils.encoding import force_unicode
+
−from django.utils.html import escape
+
−from django.utils.safestring import SafeData, EscapeData
+
−
+
−class DebugLexer(Lexer):
+
−    def __init__(self, template_string, origin):
+
−        super(DebugLexer, self).__init__(template_string, origin)
+
−
+
−    def tokenize(self):
+
−        "Return a list of tokens from a given template_string"
+
−        result, upto = [], 0
+
−        for match in tag_re.finditer(self.template_string):
+
−            start, end = match.span()
+
−            if start > upto:
+
−                result.append(self.create_token(self.template_string[upto:start], (upto, start), False))
+
−                upto = start
+
−            result.append(self.create_token(self.template_string[start:end], (start, end), True))
+
−            upto = end
+
−        last_bit = self.template_string[upto:]
+
−        if last_bit:
+
−            result.append(self.create_token(last_bit, (upto, upto + len(last_bit)), False))
+
−        return result
+
−
+
−    def create_token(self, token_string, source, in_tag):
+
−        token = super(DebugLexer, self).create_token(token_string, in_tag)
+
−        token.source = self.origin, source
+
−        return token
+
−
+
−class DebugParser(Parser):
+
−    def __init__(self, lexer):
+
−        super(DebugParser, self).__init__(lexer)
+
−        self.command_stack = []
+
−
+
−    def enter_command(self, command, token):
+
−        self.command_stack.append( (command, token.source) )
+
−
+
−    def exit_command(self):
+
−        self.command_stack.pop()
+
−
+
−    def error(self, token, msg):
+
−        return self.source_error(token.source, msg)
+
−
+
−    def source_error(self, source,msg):
+
−        e = TemplateSyntaxError(msg)
+
−        e.source = source
+
−        return e
+
−
+
−    def create_nodelist(self):
+
−        return DebugNodeList()
+
−
+
−    def create_variable_node(self, contents):
+
−        return DebugVariableNode(contents)
+
−
+
−    def extend_nodelist(self, nodelist, node, token):
+
−        node.source = token.source
+
−        super(DebugParser, self).extend_nodelist(nodelist, node, token)
+
−
+
−    def unclosed_block_tag(self, parse_until):
+
−        command, source = self.command_stack.pop()
+
−        msg = "Unclosed tag '%s'. Looking for one of: %s " % (command, ', '.join(parse_until))
+
−        raise self.source_error(source, msg)
+
−
+
−    def compile_function_error(self, token, e):
+
−        if not hasattr(e, 'source'):
+
−            e.source = token.source
+
−
+
−class DebugNodeList(NodeList):
+
−    def render_node(self, node, context):
+
−        try:
+
−            result = node.render(context)
+
−        except TemplateSyntaxError, e:
+
−            if not hasattr(e, 'source'):
+
−                e.source = node.source
+
−            raise
+
−        except Exception, e:
+
−            from sys import exc_info
+
−            wrapped = TemplateSyntaxError(u'Caught an exception while rendering: %s' % force_unicode(e, errors='replace'))
+
−            wrapped.source = node.source
+
−            wrapped.exc_info = exc_info()
+
−            raise wrapped
+
−        return result
+
−
+
−class DebugVariableNode(VariableNode):
+
−    def render(self, context):
+
−        try:
+
−            output = force_unicode(self.filter_expression.resolve(context))
+
−        except TemplateSyntaxError, e:
+
−            if not hasattr(e, 'source'):
+
−                e.source = self.source
+
−            raise
+
−        except UnicodeDecodeError:
+
−            return ''
+
−        if (context.autoescape and not isinstance(output, SafeData)) or isinstance(output, EscapeData):
+
−            return escape(output)
+
−        else:
+
−            return output