mediagoblin/tools/template.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 import jinja2
  19 from jinja2.ext import Extension
  20 from jinja2.nodes import Include, Const
  21
  22 from babel.localedata import exists
  23 from werkzeug.urls import url_quote_plus
  24
  25 from mediagoblin import mg_globals
  26 from mediagoblin import messages
  27 from mediagoblin import _version
  28 from mediagoblin.tools import common
  29 from mediagoblin.tools.translate import is_rtl
  30 from mediagoblin.tools.translate import set_thread_locale
  31 from mediagoblin.tools.translate import get_locale_from_request
  32 from mediagoblin.tools.pluginapi import get_hook_templates, hook_transform
  33 from mediagoblin.tools.timesince import timesince
  34 from mediagoblin.meddleware.csrf import render_csrf_form_token
  35
  36
  37 SETUP_JINJA_ENVS = {}
  38
  39
  40 def get_jinja_env(template_loader, locale):
  41     """
  42     Set up the Jinja environment,
  43
  44     (In the future we may have another system for providing theming;
  45     for now this is good enough.)
  46     """
  47     set_thread_locale(locale)
  48
  49     # If we have a jinja environment set up with this locale, just
  50     # return that one.
  51     if locale in SETUP_JINJA_ENVS:
  52         return SETUP_JINJA_ENVS[locale]
  53
  54     # The default config does not require a [jinja2] block.
  55     # You may create one if you wish to enable additional jinja2 extensions,
  56     # see example in config_spec.ini
  57     jinja2_config = mg_globals.global_config.get('jinja2', {})
  58     local_exts = jinja2_config.get('extensions', [])
  59
  60     # jinja2.StrictUndefined will give exceptions on references
  61     # to undefined/unknown variables in templates.
  62     template_env = jinja2.Environment(
  63         loader=template_loader, autoescape=True,
  64         undefined=jinja2.StrictUndefined,
  65         extensions=[
  66             'jinja2.ext.i18n', 'jinja2.ext.autoescape',
  67             TemplateHookExtension] + local_exts)
  68
  69     template_env.install_gettext_callables(
  70         mg_globals.thread_scope.translations.ugettext,
  71         mg_globals.thread_scope.translations.ungettext)
  72
  73     # All templates will know how to ...
  74     # ... fetch all waiting messages and remove them from the queue
  75     # ... construct a grid of thumbnails or other media
  76     # ... have access to the global and app config
  77     # ... determine if the language is rtl or ltr
  78     template_env.globals['fetch_messages'] = messages.fetch_messages
  79     template_env.globals['app_config'] = mg_globals.app_config
  80     template_env.globals['global_config'] = mg_globals.global_config
  81     template_env.globals['version'] = _version.__version__
  82     template_env.globals['auth'] = mg_globals.app.auth
  83     template_env.globals['is_rtl'] = is_rtl(locale)
  84     template_env.filters['urlencode'] = url_quote_plus
  85
  86     # add human readable fuzzy date time
  87     template_env.globals['timesince'] = timesince
  88
  89     # allow for hooking up plugin templates
  90     template_env.globals['get_hook_templates'] = get_hook_templates
  91
  92     template_env.globals = hook_transform(
  93         'template_global_context', template_env.globals)
  94
  95     #### THIS IS TEMPORARY, PLEASE FIX IT
  96     ## Notifications stuff is not yet a plugin (and we're not sure it will be),
  97     ## but it needs to add stuff to the context.  This is THE WRONG WAY TO DO IT
  98     from mediagoblin import notifications
  99     template_env.globals['get_notifications'] = notifications.get_notifications
 100     template_env.globals[
 101         'get_notification_count'] = notifications.get_notification_count
 102     template_env.globals[
 103         'get_comment_subscription'] = notifications.get_comment_subscription
 104
 105     if exists(locale):
 106         SETUP_JINJA_ENVS[locale] = template_env
 107
 108     return template_env
 109
 110
 111 # We'll store context information here when doing unit tests
 112 TEMPLATE_TEST_CONTEXT = {}
 113
 114
 115 def render_template(request, template_path, context):
 116     """
 117     Render a template with context.
 118
 119     Always inserts the request into the context, so you don't have to.
 120     Also stores the context if we're doing unit tests.  Helpful!
 121     """
 122     template = request.template_env.get_template(
 123         template_path)
 124     context['request'] = request
 125     rendered_csrf_token = render_csrf_form_token(request)
 126     if rendered_csrf_token is not None:
 127         context['csrf_token'] = render_csrf_form_token(request)
 128
 129     # allow plugins to do things to the context
 130     if request.controller_name:
 131         context = hook_transform(
 132             (request.controller_name, template_path),
 133             context)
 134
 135     # More evil: allow plugins to possibly do something to the context
 136     # in every request ever with access to the request and other
 137     # variables.  Note: this is slower than using
 138     # template_global_context
 139     context = hook_transform(
 140         'template_context_prerender', context)
 141
 142     rendered = template.render(context)
 143
 144     if common.TESTS_ENABLED:
 145         TEMPLATE_TEST_CONTEXT[template_path] = context
 146
 147     return rendered
 148
 149
 150 def clear_test_template_context():
 151     global TEMPLATE_TEST_CONTEXT
 152     TEMPLATE_TEST_CONTEXT = {}
 153
 154
 155 class TemplateHookExtension(Extension):
 156     """
 157     Easily loop through a bunch of templates from a template hook.
 158
 159     Use:
 160       {% template_hook("comment_extras") %}
 161
 162     ... will include all templates hooked into the comment_extras section.
 163     """
 164
 165     tags = set(["template_hook"])
 166
 167     def parse(self, parser):
 168         includes = []
 169         expr = parser.parse_expression()
 170         lineno = expr.lineno
 171         hook_name = expr.args[0].value
 172
 173         for template_name in get_hook_templates(hook_name):
 174             includes.append(
 175                 parser.parse_import_context(
 176                     Include(Const(template_name), True, False, lineno=lineno),
 177                     True))
 178
 179         return includes