diff options
Diffstat (limited to 'coffin/interop.py')
| -rw-r--r-- | coffin/interop.py | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/coffin/interop.py b/coffin/interop.py deleted file mode 100644 index 54120004..00000000 --- a/coffin/interop.py +++ /dev/null @@ -1,120 +0,0 @@ -"""Compatibility functions between Jinja2 and Django.
-
-General notes:
-
- - The Django ``stringfilter`` decorator is supported, but should not be
- used when writing filters specifically for Jinja: It will lose the
- attributes attached to the filter function by Jinja's
- ``environmentfilter`` and ``contextfilter`` decorators, when used
- in the wrong order.
-
- Maybe coffin should provide a custom version of stringfilter.
-
- - While transparently converting filters between Django and Jinja works
- for the most part, there is an issue with Django's
- ``mark_for_escaping``, as Jinja does not support a similar mechanism.
- Instead, for Jinja, we escape such strings immediately (whereas Django
- defers it to the template engine).
-"""
-
-import inspect
-from django.utils.safestring import SafeUnicode, SafeData, EscapeData
-from jinja2 import Markup, environmentfilter
-
-
-__all__ = (
- 'DJANGO', 'JINJA2',
- 'django_filter_to_jinja2',
- 'jinja2_filter_to_django',
- 'guess_filter_type',)
-
-
-DJANGO = 'django'
-JINJA2 = 'jinja2'
-
-
-def django_filter_to_jinja2(filter_func):
- """
- Note: Due to the way this function is used by
- ``coffin.template.Library``, it needs to be able to handle native
- Jinja2 filters and pass them through unmodified. This necessity
- stems from the fact that it is not always possible to determine
- the type of a filter.
-
- TODO: Django's "func.is_safe" is not yet handled
- """
- def _convert(v):
- if isinstance(v, SafeData):
- return Markup(v)
- if isinstance(v, EscapeData):
- return Markup.escape(v) # not 100% equivalent, see mod docs
- return v
- def conversion_wrapper(*args, **kwargs):
- result = filter_func(*args, **kwargs)
- return _convert(result)
- # Jinja2 supports a similar machanism to Django's
- # ``needs_autoescape`` filters: environment filters. We can
- # thus support Django filters that use it in Jinja2 with just
- # a little bit of argument rewriting.
- if hasattr(filter_func, 'needs_autoescape'):
- @environmentfilter
- def autoescape_wrapper(environment, *args, **kwargs):
- kwargs['autoescape'] = environment.autoescape
- return conversion_wrapper(*args, **kwargs)
- return autoescape_wrapper
- else:
- return conversion_wrapper
-
-
-def jinja2_filter_to_django(filter_func):
- """
- Note: Due to the way this function is used by
- ``coffin.template.Library``, it needs to be able to handle native
- Django filters and pass them through unmodified. This necessity
- stems from the fact that it is not always possible to determine
- the type of a filter.
- """
- if guess_filter_type(filter_func)[0] == DJANGO:
- return filter_func
- def _convert(v):
- # TODO: for now, this is not even necessary: Markup strings have
- # a custom replace() method that is immume to Django's escape()
- # attempts.
- #if isinstance(v, Markup):
- # return SafeUnicode(v) # jinja is always unicode
- # ... Jinja does not have a EscapeData equivalent
- return v
- def wrapped(value, *args, **kwargs):
- result = filter_func(value, *args, **kwargs)
- return _convert(result)
- return wrapped
-
-
-def guess_filter_type(filter_func):
- """Returns a 2-tuple of (type, can_be_ported).
-
- ``type`` is one of DJANGO, JINJA2, or ``False`` if the type can
- not be determined.
-
- ``can_be_ported`` is ``True`` if we believe the filter could be
- ported to the other engine, respectively, or ``False`` if we know
- it can't.
-
- TODO: May not yet use all possible clues, e.g. decorators like
- ``stringfilter``.
- TOOD: Needs tests.
- """
- if hasattr(filter_func, 'contextfilter') or \
- hasattr(filter_func, 'environmentfilter'):
- return JINJA2, False
-
- args = inspect.getargspec(filter_func)
- if len(args[0]) - (len(args[3]) if args[3] else 0) > 2:
- return JINJA2, False
-
- if hasattr(filter_func, 'needs_autoescape'):
- return DJANGO, True
-
- # Looks like your run of the mill Python function, which are
- # easily convertible in either direction.
- return False, True
\ No newline at end of file |