Files
deb-python-jingo/jingo/__init__.py
James Socol fee58b2b89 Version 0.9
2016-05-30 14:31:52 -04:00

282 lines
8.6 KiB
Python

"""Adapter for using Jinja2 with Django."""
from __future__ import unicode_literals
import functools
import logging
import re
from django.apps import apps
from django.conf import settings
from django.template.base import Origin, TemplateDoesNotExist
from django.template.loader import BaseLoader
try:
from importlib import import_module
except ImportError:
from django.utils.importlib import import_module
try:
import importlib.util
if hasattr(importlib.util, 'find_spec'): # Py3>=3.4
def has_helpers(config):
module = '%s.helpers' % (config.name,)
return importlib.util.find_spec(module) is not None
else: # Py3<3.4
def has_helpers(config):
# For Python 3.3, just try to import the module. Unfortunately,
# this changes the contract slightly for Python 3.3: if there is an
# module but this raises a legitimate ImportError, jingo will act
# as if the module doesn't exist. The intent is that we raise
# legitimate ImportErrors but ignore missing modules.
try:
import_module('%s.helpers' % config.name)
return True
except ImportError:
return False
except ImportError:
import imp
def has_helpers(config):
try:
imp.find_module('helpers', [config.path])
return True
except ImportError:
return False
import jinja2
try:
from django.template.engine import Engine
has_engine = True
def get_standard_processors():
return Engine.get_default().template_context_processors
except ImportError:
from django.template.context import get_standard_processors
has_engine = False
VERSION = (0, 9, 0)
__version__ = '.'.join(map(str, VERSION))
EXCLUDE_APPS = (
'admin',
'admindocs',
'registration',
'context_processors',
)
log = logging.getLogger('jingo')
_helpers_loaded = False
class Template(jinja2.Template):
def render(self, context={}):
"""Render's a template, context can be a Django Context or a
dictionary.
"""
# flatten the Django Context into a single dictionary.
context_dict = {}
if hasattr(context, 'dicts'):
for d in context.dicts:
context_dict.update(d)
else:
context_dict = context
# Django Debug Toolbar needs a RequestContext-like object in order
# to inspect context.
class FakeRequestContext:
dicts = [context]
context = FakeRequestContext()
# Used by debug_toolbar.
if settings.TEMPLATE_DEBUG:
from django.test import signals
self.origin = Origin(self.filename)
signals.template_rendered.send(sender=self, template=self,
context=context)
return super(Template, self).render(context_dict)
class Environment(jinja2.Environment):
template_class = Template
def get_template(self, name, parent=None, globals=None):
"""Make sure our helpers get loaded before any templates."""
load_helpers()
return super(Environment, self).get_template(name, parent, globals)
def from_string(self, source, globals=None, template_class=None):
load_helpers()
return super(Environment, self).from_string(source, globals,
template_class)
_env = None
def get_env():
"""Configure and return a jinja2 Environment."""
global _env
if _env:
return _env
# Mimic Django's setup by loading templates from directories in
# TEMPLATE_DIRS and packages in INSTALLED_APPS.
loaders = [jinja2.FileSystemLoader(d) for d in settings.TEMPLATE_DIRS]
loaders += [jinja2.PackageLoader(c.name) for c in apps.get_app_configs()]
opts = {
'trim_blocks': True,
'extensions': ['jinja2.ext.i18n', 'jingo.ext.JingoExtension'],
'autoescape': True,
'auto_reload': settings.DEBUG,
'loader': jinja2.ChoiceLoader(loaders),
}
if hasattr(settings, 'JINJA_CONFIG'):
if hasattr(settings.JINJA_CONFIG, '__call__'):
config = settings.JINJA_CONFIG()
else:
config = settings.JINJA_CONFIG
opts.update(config)
e = Environment(**opts)
# Install null translations since gettext isn't always loaded up during
# testing.
if ('jinja2.ext.i18n' in e.extensions or
'jinja2.ext.InternationalizationExtension' in e.extensions):
e.install_null_translations()
_env = e
return e
def render_to_string(request, template, context=None):
"""
Render a template into a string.
"""
def get_context():
c = {} if context is None else context.copy()
for processor in get_standard_processors():
c.update(processor(request))
return c
# If it's not a Template, it must be a path to be loaded.
if not isinstance(template, jinja2.environment.Template):
template = get_env().get_template(template)
return template.render(get_context())
def load_helpers():
"""Try to import ``helpers.py`` from each app in INSTALLED_APPS."""
# We want to wait as long as possible to load helpers so there aren't any
# weird circular imports with jingo.
global _helpers_loaded
if _helpers_loaded:
return
_helpers_loaded = True
for config in apps.get_app_configs():
if not has_helpers(config):
continue
import_module('%s.helpers' % config.name)
class Register(object):
"""Decorators to add filters and functions to the template Environment."""
def filter(self, f=None, override=True):
"""Adds the decorated function to Jinja's filter library."""
def decorator(f):
@functools.wraps(f)
def wrapper(*args, **kw):
return f(*args, **kw)
return self.filter(wrapper, override)
if not f:
return decorator
if override or f.__name__ not in get_env().filters:
get_env().filters[f.__name__] = f
return f
def function(self, f=None, override=True):
"""Adds the decorated function to Jinja's global namespace."""
def decorator(f):
@functools.wraps(f)
def wrapper(*args, **kw):
return f(*args, **kw)
return self.function(wrapper, override)
if not f:
return decorator
if override or f.__name__ not in get_env().globals:
get_env().globals[f.__name__] = f
return f
def inclusion_tag(self, template):
"""Adds a function to Jinja, but like Django's @inclusion_tag."""
def decorator(f):
@functools.wraps(f)
def wrapper(*args, **kw):
context = f(*args, **kw)
t = get_env().get_template(template).render(context)
return jinja2.Markup(t)
return self.function(wrapper)
return decorator
register = Register()
class Loader(BaseLoader):
is_usable = True
def __init__(self):
if has_engine:
super(Loader, self).__init__(Engine.get_default())
else:
super(Loader, self).__init__()
include_pattern = getattr(settings, 'JINGO_INCLUDE_PATTERN', None)
if include_pattern:
self.include_re = re.compile(include_pattern)
else:
self.include_re = None
def _valid_template(self, template_name):
if self.include_re:
if not self.include_re.search(template_name):
return False
if hasattr(template_name, 'split'):
app = template_name.split('/')[0]
if app in getattr(settings, 'JINGO_EXCLUDE_APPS', EXCLUDE_APPS):
return False
return True
def load_template(self, template_name, template_dirs=None):
if not self._valid_template(template_name):
raise TemplateDoesNotExist(template_name)
try:
template = get_env().get_template(template_name)
return template, template.filename
except jinja2.TemplateNotFound:
raise TemplateDoesNotExist(template_name)
def load_template_source(self, template_name, template_dirs=None):
if not self._valid_template(template_name):
raise TemplateDoesNotExist(template_name)
try:
template = get_env().get_template(template_name)
except jinja2.TemplateNotFound:
raise TemplateDoesNotExist(template_name)
with open(template.filename, 'rb') as fp:
return (fp.read().decode(settings.FILE_CHARSET), template.filename)