Added getSingleIndexedParamValue() that retrieves an index into a list of
values from the named query parameter, and then indexes into the supplied list
of values to return the corresponding value from the list. Used to convert
numeric index query parameters passed by POST to the GET redirect target, so
that the GET code can display messages, etc. (without passing the message
itself as a query argument and having to escape it or have silly people pass
in their own...).
#!/usr/bin/python2.5
#
# Copyright 2008 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Helpers for manipulating templates.
"""
__authors__ = [
'"Todd Larsen" <tlarsen@google.com>',
'"Pawel Solyga" <pawel.solyga@gmail.com>'
]
def makeSiblingTemplatesList(templates, new_template_file,
default_template=None):
"""Converts template paths into a list of "sibling" templates.
Args:
templates: search list of templates (or just a single template not in a
list) from which template paths will be extracted (discarding the final
template file name of each template)
new_template_file: new "sibling" template file to append to each extracted
template path
default_template: a default template (or a list of them) to append to the
end of the generated "sibling" template paths; default is None
Returns:
A list of potential "sibling" templates named by new_template_file located
in the paths of the templates in the supplied list. For example, from:
['foo/bar/the_old_template.html', 'foo/the_old_template.html']
to:
['foo/bar/some_new_template.html', 'foo/some_new_template.html']
"""
if not isinstance(templates, (list, tuple)):
templates = [templates]
if default_template is None:
default_template = []
if not isinstance(default_template, (list, tuple)):
default_template = [default_template]
sibling_templates = [
'%s/%s' % (t.rsplit('/', 1)[0], new_template_file) for t in templates]
return sibling_templates + default_template
def unescape(html):
"""Returns the given HTML with ampersands, quotes and carets decoded.
"""
if not isinstance(html, basestring):
html = str(html)
html.replace('&', '&').replace('<', '<')
html.replace('>', '>').replace('"', '"').replace(''',"'")
return html
def getSingleIndexedParamValue(request, param_name, values=()):
"""Returns a value indexed by a query parameter in the HTTP request.
Args:
request: the Django HTTP request object
param_name: name of the query parameter in the HTTP request
values: list (or tuple) of ordered values; one of which is
retrieved by the index value of the param_name argument in
the HTTP request
Returns:
None if the query parameter was not present, was not an integer, or
was an integer that is not a valid [0..len(values)-1] index into
the values list.
Otherwise, returns values[int(param_name value)]
"""
value_idx = request.GET.get(param_name)
if isinstance(value_idx, (tuple, list)):
# keep only the first argument if multiple are present
value_idx = value_idx[0]
try:
# GET parameter 'param_name' should be an integer value index
value_idx = int(value_idx)
except:
# ignore bogus or missing parameter values, so return None (no message)
return None
if value_idx < 0:
# value index out of range, so return None (no value)
return None
if value_idx >= len(values):
# value index out of range, so return None (no value)
return None
# return value associated with valid value index
return values[value_idx]
def getSingleIndexedParamValueIfMissing(value, request, param_name,
values=()):
"""Returns missing value indexed by a query parameter in the HTTP request.
Args:
value: an existing value, or a "False" value such as None
request, param_name, values: see getSingleIndexParamValue()
Returns:
value, if value is "non-False"
Otherwise, returns getSingleIndexedParamValue() result.
"""
if value:
# value already present, so return it
return value
return getSingleIndexedParamValue(request, param_name, values=values)
# TODO(tlarsen): write getMultipleIndexParamValues() that returns a
# list of values if present, omitting those values that are
# out of range