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 import six
  18
  19 import jinja2
  20 from jinja2.ext import Extension
  21 from jinja2.nodes import Include, Const
  22
  23 from babel.localedata import exists
  24 from werkzeug.urls import url_quote_plus
  25
  26 from mediagoblin import mg_globals
  27 from mediagoblin import messages
  28 from mediagoblin import _version
  29 from mediagoblin.tools import common
  30 from mediagoblin.tools.translate import is_rtl
  31 from mediagoblin.tools.translate import set_thread_locale
  32 from mediagoblin.tools.translate import get_locale_from_request
  33 from mediagoblin.tools.pluginapi import get_hook_templates, hook_transform
  34 from mediagoblin.tools.timesince import timesince
  35 from mediagoblin.meddleware.csrf import render_csrf_form_token
  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     if six.PY2:
  70         template_env.install_gettext_callables(mg_globals.thread_scope.translations.ugettext,
  71                                            mg_globals.thread_scope.translations.ungettext)
  72     else:
  73         template_env.install_gettext_callables(mg_globals.thread_scope.translations.gettext,
  74                                            mg_globals.thread_scope.translations.ngettext)
  75
  76     # All templates will know how to ...
  77     # ... fetch all waiting messages and remove them from the queue
  78     # ... construct a grid of thumbnails or other media
  79     # ... have access to the global and app config
  80     # ... determine if the language is rtl or ltr
  81     template_env.globals['fetch_messages'] = messages.fetch_messages
  82     template_env.globals['app_config'] = mg_globals.app_config
  83     template_env.globals['global_config'] = mg_globals.global_config
  84     template_env.globals['version'] = _version.__version__
  85     template_env.globals['auth'] = mg_globals.app.auth
  86     template_env.globals['is_rtl'] = is_rtl(locale)
  87     template_env.filters['urlencode'] = url_quote_plus
  88
  89     # add human readable fuzzy date time
  90     template_env.globals['timesince'] = timesince
  91
  92     # allow for hooking up plugin templates
  93     template_env.globals['get_hook_templates'] = get_hook_templates
  94
  95     template_env.globals = hook_transform(
  96         'template_global_context', template_env.globals)
  97
  98     #### THIS IS TEMPORARY, PLEASE FIX IT
  99     ## Notifications stuff is not yet a plugin (and we're not sure it will be),
 100     ## but it needs to add stuff to the context.  This is THE WRONG WAY TO DO IT
 101     from mediagoblin import notifications
 102     template_env.globals['get_notifications'] = notifications.get_notifications
 103     template_env.globals[
 104         'get_notification_count'] = notifications.get_notification_count
 105     template_env.globals[
 106         'get_comment_subscription'] = notifications.get_comment_subscription
 107
 108     if exists(locale):
 109         SETUP_JINJA_ENVS[locale] = template_env
 110
 111     return template_env
 112
 113
 114 # We'll store context information here when doing unit tests
 115 TEMPLATE_TEST_CONTEXT = {}
 116
 117
 118 def render_template(request, template_path, context):
 119     """
 120     Render a template with context.
 121
 122     Always inserts the request into the context, so you don't have to.
 123     Also stores the context if we're doing unit tests.  Helpful!
 124     """
 125     template = request.template_env.get_template(
 126         template_path)
 127     context['request'] = request
 128     rendered_csrf_token = render_csrf_form_token(request)
 129     if rendered_csrf_token is not None:
 130         context['csrf_token'] = render_csrf_form_token(request)
 131
 132     # allow plugins to do things to the context
 133     if request.controller_name:
 134         context = hook_transform(
 135             (request.controller_name, template_path),
 136             context)
 137
 138     # More evil: allow plugins to possibly do something to the context
 139     # in every request ever with access to the request and other
 140     # variables.  Note: this is slower than using
 141     # template_global_context
 142     context = hook_transform(
 143         'template_context_prerender', context)
 144
 145     rendered = template.render(context)
 146
 147     if common.TESTS_ENABLED:
 148         TEMPLATE_TEST_CONTEXT[template_path] = context
 149
 150     return rendered
 151
 152
 153 def clear_test_template_context():
 154     global TEMPLATE_TEST_CONTEXT
 155     TEMPLATE_TEST_CONTEXT = {}
 156
 157
 158 class TemplateHookExtension(Extension):
 159     """
 160     Easily loop through a bunch of templates from a template hook.
 161
 162     Use:
 163       {% template_hook("comment_extras") %}
 164
 165     ... will include all templates hooked into the comment_extras section.
 166     """
 167
 168     tags = set(["template_hook"])
 169
 170     def parse(self, parser):
 171         includes = []
 172         expr = parser.parse_expression()
 173         lineno = expr.lineno
 174         hook_name = expr.args[0].value
 175
 176         for template_name in get_hook_templates(hook_name):
 177             includes.append(
 178                 parser.parse_import_context(
 179                     Include(Const(template_name), True, False, lineno=lineno),
 180                     True))
 181
 182         return includes