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deb-python-jingo/jingo/monkey.py
Andrew Williamson 0d293ae8ae django 1.8 compatability fixes
Fix #70
2015-05-13 10:00:28 -04:00

113 lines
3.6 KiB
Python

"""
Django marks its form HTML "safe" according to its own rules, which Jinja2 does
not recognize.
This monkeypatches Django to support the ``__html__`` protocol used in Jinja2
templates. ``Form``, ``BoundField``, ``ErrorList``, and other form objects that
render HTML through their ``__unicode__`` method are extended with ``__html__``
so they can be rendered in Jinja2 templates without adding ``|safe``.
Call the ``patch()`` function to execute the patch. It must be called
before ``django.forms`` is imported for the conditional_escape patch to work
properly. The root URLconf is the recommended location for calling ``patch()``.
Usage::
import jingo.monkey
jingo.monkey.patch()
This patch was originally developed by Jeff Balogh and this version is taken
from the nuggets project at
https://github.com/mozilla/nuggets/blob/master/safe_django_forms.py
"""
from __future__ import unicode_literals
import django.utils.encoding
import django.utils.html
import django.utils.safestring
from django.utils import six
try:
# This was removed in Django 1.5+. We add it back to support Django 1.4.
from django.utils.encoding import StrAndUnicode
has_str_and_unicode = True
except ImportError:
has_str_and_unicode = False
from django.utils.encoding import python_2_unicode_compatible
@python_2_unicode_compatible
class StrAndUnicode(object):
def __str__(self):
return self.code
# This function gets directly imported within Django, so this change needs to
# happen before too many Django imports happen.
def conditional_escape(html):
"""
Similar to escape(), except that it doesn't operate on pre-escaped strings.
"""
if hasattr(html, '__html__'):
return html.__html__()
elif isinstance(html, django.utils.safestring.SafeData):
return html
return django.utils.html.escape(html)
# Django uses SafeData to mark a string that has already been escaped or
# otherwise deemed safe. This __html__ method lets Jinja know about that too.
def __html__(self):
"""
Returns the html representation of a string.
Allows interoperability with other template engines.
"""
return six.text_type(self)
# Django uses StrAndUnicode for classes like Form, BoundField, Widget which
# have a __unicode__ method which returns escaped html. We replace
# StrAndUnicode with SafeStrAndUnicode to get the __html__ method.
class SafeStrAndUnicode(StrAndUnicode):
"""A class whose __str__ and __html__ returns __unicode__."""
def __html__(self):
return six.text_type(self)
def patch():
django.utils.html.conditional_escape = conditional_escape
django.utils.safestring.SafeData.__html__ = __html__
# forms imports have to come after we patch conditional_escape.
from django.forms import forms, formsets, util, widgets
# Replace StrAndUnicode with SafeStrAndUnicode in the inheritance
# for all these classes.
classes = [
forms.BaseForm,
forms.BoundField,
formsets.BaseFormSet,
util.ErrorDict,
util.ErrorList,
widgets.Media,
widgets.RadioFieldRenderer,
]
try:
classes.append(widgets.RadioChoiceInput)
except AttributeError:
classes.append(widgets.RadioInput)
if has_str_and_unicode:
for cls in classes:
bases = list(cls.__bases__)
if StrAndUnicode in bases:
idx = bases.index(StrAndUnicode)
bases[idx] = SafeStrAndUnicode
cls.__bases__ = tuple(bases)
for cls in classes:
if not hasattr(cls, '__html__'):
cls.__html__ = __html__