Refactored getting the list of template loaders.

This provides the opportunity to move utility functions specific to the
Django Template Language outside of django.template.loader.
This commit is contained in:
Aymeric Augustin 2014-11-15 20:58:26 +01:00
parent 1851dcf377
commit 9eeb788cfb
8 changed files with 102 additions and 93 deletions

View File

@ -1,13 +1,9 @@
import warnings
from django.core.exceptions import ImproperlyConfigured
from django.template.base import Origin, Template, Context, TemplateDoesNotExist
from django.conf import settings
from django.template.base import Origin, Template, Context, TemplateDoesNotExist
from django.template.loaders.utils import get_template_loaders
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.module_loading import import_string
from django.utils import six
template_source_loaders = None
class LoaderOrigin(Origin):
@ -26,58 +22,8 @@ def make_origin(display_name, loader, name, dirs):
return None
def find_template_loader(loader):
if isinstance(loader, (tuple, list)):
loader, args = loader[0], loader[1:]
else:
args = []
if isinstance(loader, six.string_types):
TemplateLoader = import_string(loader)
if hasattr(TemplateLoader, 'load_template_source'):
func = TemplateLoader(*args)
else:
warnings.warn(
"Function-based template loaders are deprecated. Please use "
"class-based template loaders instead. Inherit base.Loader "
"and provide a load_template_source() method.",
RemovedInDjango20Warning, stacklevel=2)
# Try loading module the old way - string is full path to callable
if args:
raise ImproperlyConfigured(
"Error importing template source loader %s - can't pass "
"arguments to function-based loader." % loader
)
func = TemplateLoader
if not func.is_usable:
import warnings
warnings.warn(
"Your TEMPLATE_LOADERS setting includes %r, but your Python "
"installation doesn't support that type of template loading. "
"Consider removing that line from TEMPLATE_LOADERS." % loader
)
return None
else:
return func
else:
raise ImproperlyConfigured('Loader does not define a "load_template" callable template source loader')
def find_template(name, dirs=None):
# Calculate template_source_loaders the first time the function is executed
# because putting this logic in the module-level namespace may cause
# circular import errors. See Django ticket #1292.
global template_source_loaders
if template_source_loaders is None:
loaders = []
for loader_name in settings.TEMPLATE_LOADERS:
loader = find_template_loader(loader_name)
if loader is not None:
loaders.append(loader)
template_source_loaders = tuple(loaders)
for loader in template_source_loaders:
for loader in get_template_loaders():
try:
source, display_name = loader(name, dirs)
return (source, make_origin(display_name, loader, name, dirs))

View File

@ -5,7 +5,8 @@ to load templates from them in order, caching the result.
import hashlib
from django.template.base import TemplateDoesNotExist
from django.template.loader import get_template_from_string, find_template_loader, make_origin
from django.template.loader import get_template_from_string, make_origin
from django.template.loaders.utils import find_template_loader
from django.utils.encoding import force_bytes
from .base import Loader as BaseLoader

View File

@ -0,0 +1,57 @@
import warnings
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.utils import lru_cache
from django.utils import six
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.module_loading import import_string
@lru_cache.lru_cache()
def get_template_loaders():
loaders = []
for loader_name in settings.TEMPLATE_LOADERS:
loader = find_template_loader(loader_name)
if loader is not None:
loaders.append(loader)
# Immutable return value because it will be cached and shared by callers.
return tuple(loaders)
def find_template_loader(loader):
if isinstance(loader, (tuple, list)):
loader, args = loader[0], loader[1:]
else:
args = []
if isinstance(loader, six.string_types):
TemplateLoader = import_string(loader)
if hasattr(TemplateLoader, 'load_template_source'):
func = TemplateLoader(*args)
else:
warnings.warn(
"Function-based template loaders are deprecated. "
"Please use class-based template loaders instead. "
"Inherit django.template.loaders.base.Loader "
"and provide a load_template_source() method.",
RemovedInDjango20Warning, stacklevel=2)
# Try loading module the old way - string is full path to callable
if args:
raise ImproperlyConfigured(
"Error importing template source loader %s - can't pass "
"arguments to function-based loader." % loader)
func = TemplateLoader
if not func.is_usable:
warnings.warn(
"Your TEMPLATE_LOADERS setting includes %r, but your Python "
"installation doesn't support that type of template loading. "
"Consider removing that line from TEMPLATE_LOADERS." % loader)
return None
else:
return func
else:
raise ImproperlyConfigured(
"Invalid value in TEMPLATE_LOADERS: %r" % loader)

View File

@ -87,8 +87,8 @@ def clear_context_processors_cache(**kwargs):
@receiver(setting_changed)
def clear_template_loaders_cache(**kwargs):
if kwargs['setting'] == 'TEMPLATE_LOADERS':
from django.template import loader
loader.template_source_loaders = None
from django.template.loaders.utils import get_template_loaders
get_template_loaders.cache_clear()
@receiver(setting_changed)

View File

@ -12,6 +12,7 @@ from django.http import (HttpResponse, HttpResponseNotFound, HttpRequest,
build_request_repr)
from django.template import Template, Context, TemplateDoesNotExist
from django.template.defaultfilters import force_escape, pprint
from django.template.loaders.utils import get_template_loaders
from django.utils.datastructures import MultiValueDict
from django.utils.html import escape
from django.utils.encoding import force_bytes, smart_text
@ -279,14 +280,15 @@ class ExceptionReporter(object):
"""Return a dictionary containing traceback information."""
if self.exc_type and issubclass(self.exc_type, TemplateDoesNotExist):
from django.template.loader import template_source_loaders
self.template_does_not_exist = True
self.loader_debug_info = []
# If the template_source_loaders haven't been populated yet, you need
# to provide an empty list for this for loop to not fail.
if template_source_loaders is None:
template_source_loaders = []
for loader in template_source_loaders:
# If Django fails in get_template_loaders, provide an empty list
# for the following loop to not fail.
try:
template_loaders = get_template_loaders()
except Exception:
template_loaders = []
for loader in template_loaders:
try:
source_list_func = loader.get_template_sources
# NOTE: This assumes exc_value is the name of the template that

View File

@ -22,6 +22,7 @@ except ImportError:
from django.template import TemplateDoesNotExist, Context
from django.template.loaders.eggs import Loader as EggLoader
from django.template.loaders.utils import find_template_loader
from django.template import loader
from django.test import TestCase, override_settings
from django.utils import six
@ -127,7 +128,7 @@ class CachedLoader(TestCase):
def test_missing_template_is_cached(self):
"#19949 -- Check that the missing template is cached."
template_loader = loader.find_template_loader(settings.TEMPLATE_LOADERS[0])
template_loader = find_template_loader(settings.TEMPLATE_LOADERS[0])
# Empty cache, which may be filled from previous tests.
template_loader.reset()
# Check that 'missing.html' isn't already in cache before 'missing.html' is loaded

View File

@ -14,7 +14,8 @@ from django.contrib.auth.models import Group
from django.core import urlresolvers
from django.template import (base as template_base, loader, Context,
RequestContext, Template, TemplateSyntaxError)
from django.template.loaders import app_directories, filesystem, cached
from django.template.loaders import app_directories, filesystem
from django.template.loaders.utils import get_template_loaders
from django.test import RequestFactory, TestCase
from django.test.utils import override_settings, extend_sys_path
from django.utils.deprecation import RemovedInDjango19Warning, RemovedInDjango20Warning
@ -218,21 +219,27 @@ class TemplateLoaderTests(TestCase):
@override_settings(TEMPLATE_DEBUG=True)
def test_loader_debug_origin(self):
# We rely on the fact that runtests.py sets up TEMPLATE_DIRS to
# point to a directory containing a login.html file. Also that
# the file system and app directories loaders both inherit the
# load_template method from the base Loader class, so we only need
# to test one of them.
# point to a directory containing a login.html file.
load_name = 'login.html'
# We also rely on the fact the file system and app directories loaders
# both inherit the load_template method from the base Loader class, so
# we only need to test one of them.
template = loader.get_template(load_name)
template_name = template.nodelist[0].source[0].name
self.assertTrue(template_name.endswith(load_name),
'Template loaded by filesystem loader has incorrect name for debug page: %s' % template_name)
# Also test the cached loader, since it overrides load_template
cache_loader = cached.Loader(('',))
cache_loader._cached_loaders = loader.template_source_loaders
loader.template_source_loaders = (cache_loader,)
@override_settings(TEMPLATE_LOADERS=[
('django.template.loaders.cached.Loader',
['django.template.loaders.filesystem.Loader']),
])
@override_settings(TEMPLATE_DEBUG=True)
def test_cached_loader_debug_origin(self):
# Same comment as in test_loader_debug_origin.
load_name = 'login.html'
# Test the cached loader separately since it overrides load_template.
template = loader.get_template(load_name)
template_name = template.nodelist[0].source[0].name
self.assertTrue(template_name.endswith(load_name),
@ -243,15 +250,15 @@ class TemplateLoaderTests(TestCase):
self.assertTrue(template_name.endswith(load_name),
'Cached template loaded through cached loader has incorrect name for debug page: %s' % template_name)
@override_settings(TEMPLATE_DEBUG=True)
def test_loader_origin(self):
with self.settings(TEMPLATE_DEBUG=True):
template = loader.get_template('login.html')
self.assertEqual(template.origin.loadname, 'login.html')
template = loader.get_template('login.html')
self.assertEqual(template.origin.loadname, 'login.html')
@override_settings(TEMPLATE_DEBUG=True)
def test_string_origin(self):
with self.settings(TEMPLATE_DEBUG=True):
template = Template('string template')
self.assertEqual(template.origin.source, 'string template')
template = Template('string template')
self.assertEqual(template.origin.source, 'string template')
def test_debug_false_origin(self):
template = loader.get_template('login.html')
@ -613,7 +620,9 @@ class TemplateTests(TestCase):
if output != result:
failures.append("Template test (Cached='%s', TEMPLATE_STRING_IF_INVALID='%s', TEMPLATE_DEBUG=%s): %s -- FAILED. Expected %r, got %r" % (is_cached, invalid_str, template_debug, name, result, output))
loader.template_source_loaders[0].reset()
# This relies on get_template_loaders() memoizing its
# result. All callers get the same iterable of loaders.
get_template_loaders()[0].reset()
if template_base.invalid_var_format_string:
expected_invalid_str = 'INVALID'

View File

@ -8,8 +8,7 @@ import os
import itertools
from django.core.urlresolvers import reverse, NoReverseMatch
from django.template import (TemplateSyntaxError,
Context, Template, loader)
from django.template import TemplateSyntaxError, Context, Template
import django.template.context
from django.test import Client, TestCase, override_settings
from django.test.client import encode_file, RequestFactory
@ -902,13 +901,6 @@ class ExceptionTests(TestCase):
@override_settings(ROOT_URLCONF='test_client_regress.urls')
class TemplateExceptionTests(TestCase):
def setUp(self):
# Reset the loaders so they don't try to render cached templates.
if loader.template_source_loaders is not None:
for template_loader in loader.template_source_loaders:
if hasattr(template_loader, 'reset'):
template_loader.reset()
@override_settings(
TEMPLATE_DIRS=(os.path.join(os.path.dirname(upath(__file__)), 'bad_templates'),)
)
@ -916,9 +908,10 @@ class TemplateExceptionTests(TestCase):
"Errors found when rendering 404 error templates are re-raised"
try:
self.client.get("/no_such_view/")
self.fail("Should get error about syntax error in template")
except TemplateSyntaxError:
pass
else:
self.fail("Should get error about syntax error in template")
# We need two different tests to check URLconf substitution - one to check