Factor out direct use of the page object
Instead of directly using the page object in the html,
pass around page_name. This will make it easier to remove
Page in favor of a simpler implementation.
# Wrapper for loading templates from storage of some sort (e.g. filesystem, database).
#
# This uses the TEMPLATE_LOADERS setting, which is a list of loaders to use.
# Each loader is expected to have this interface:
#
# callable(name, dirs=[])
#
# name is the template name.
# dirs is an optional list of directories to search instead of TEMPLATE_DIRS.
#
# The loader should return a tuple of (template_source, path). The path returned
# might be shown to the user for debugging purposes, so it should identify where
# the template was loaded from.
#
# Each loader should have an "is_usable" attribute set. This is a boolean that
# specifies whether the loader can be used in this Python installation. Each
# loader is responsible for setting this when it's initialized.
#
# For example, the eggs loader (which is capable of loading templates from
# Python eggs) sets is_usable to False if the "pkg_resources" module isn't
# installed, because pkg_resources is necessary to read eggs.
from django.core.exceptions import ImproperlyConfigured
from django.template import Origin, Template, Context, TemplateDoesNotExist, add_to_builtins
from django.conf import settings
template_source_loaders = None
class LoaderOrigin(Origin):
def __init__(self, display_name, loader, name, dirs):
super(LoaderOrigin, self).__init__(display_name)
self.loader, self.loadname, self.dirs = loader, name, dirs
def reload(self):
return self.loader(self.loadname, self.dirs)[0]
def make_origin(display_name, loader, name, dirs):
if settings.TEMPLATE_DEBUG:
return LoaderOrigin(display_name, loader, name, dirs)
else:
return None
def find_template_source(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 path in settings.TEMPLATE_LOADERS:
i = path.rfind('.')
module, attr = path[:i], path[i+1:]
try:
mod = __import__(module, globals(), locals(), [attr])
except ImportError, e:
raise ImproperlyConfigured, 'Error importing template source loader %s: "%s"' % (module, e)
try:
func = getattr(mod, attr)
except AttributeError:
raise ImproperlyConfigured, 'Module "%s" does not define a "%s" callable template source loader' % (module, attr)
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." % path)
else:
loaders.append(func)
template_source_loaders = tuple(loaders)
for loader in template_source_loaders:
try:
source, display_name = loader(name, dirs)
return (source, make_origin(display_name, loader, name, dirs))
except TemplateDoesNotExist:
pass
raise TemplateDoesNotExist, name
def get_template(template_name):
"""
Returns a compiled Template object for the given template name,
handling template inheritance recursively.
"""
source, origin = find_template_source(template_name)
template = get_template_from_string(source, origin, template_name)
return template
def get_template_from_string(source, origin=None, name=None):
"""
Returns a compiled Template object for the given template code,
handling template inheritance recursively.
"""
return Template(source, origin, name)
def render_to_string(template_name, dictionary=None, context_instance=None):
"""
Loads the given template_name and renders it with the given dictionary as
context. The template_name may be a string to load a single template using
get_template, or it may be a tuple to use select_template to find one of
the templates in the list. Returns a string.
"""
dictionary = dictionary or {}
if isinstance(template_name, (list, tuple)):
t = select_template(template_name)
else:
t = get_template(template_name)
if context_instance:
context_instance.update(dictionary)
else:
context_instance = Context(dictionary)
return t.render(context_instance)
def select_template(template_name_list):
"Given a list of template names, returns the first that can be loaded."
for template_name in template_name_list:
try:
return get_template(template_name)
except TemplateDoesNotExist:
continue
# If we get here, none of the templates could be loaded
raise TemplateDoesNotExist, ', '.join(template_name_list)
add_to_builtins('django.template.loader_tags')