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.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 SETUP_JINJA_ENVS = {}
  37
  38
  39 def get_jinja_env(app, template_loader, locale):
  40     """
  41     Set up the Jinja environment,
  42
  43     (In the future we may have another system for providing theming;
  44     for now this is good enough.)
  45     """
  46     set_thread_locale(locale)
  47
  48     # If we have a jinja environment set up with this locale, just
  49     # return that one.
  50     if locale in SETUP_JINJA_ENVS:
  51         return SETUP_JINJA_ENVS[locale]
  52
  53     # The default config does not require a [jinja2] block.
  54     # You may create one if you wish to enable additional jinja2 extensions,
  55     # see example in config_spec.ini
  56     jinja2_config = app.global_config.get('jinja2', {})
  57     local_exts = jinja2_config.get('extensions', [])
  58
  59     # jinja2.StrictUndefined will give exceptions on references
  60     # to undefined/unknown variables in templates.
  61     template_env = jinja2.Environment(
  62         loader=template_loader, autoescape=True,
  63         undefined=jinja2.StrictUndefined,
  64         extensions=[
  65             'jinja2.ext.i18n', 'jinja2.ext.autoescape',
  66             TemplateHookExtension] + local_exts)
  67
  68     if six.PY2:
  69         template_env.install_gettext_callables(mg_globals.thread_scope.translations.ugettext,
  70                                            mg_globals.thread_scope.translations.ungettext)
  71     else:
  72         template_env.install_gettext_callables(mg_globals.thread_scope.translations.gettext,
  73                                            mg_globals.thread_scope.translations.ngettext)
  74
  75     # All templates will know how to ...
  76     # ... fetch all waiting messages and remove them from the queue
  77     # ... construct a grid of thumbnails or other media
  78     # ... have access to the global and app config
  79     # ... determine if the language is rtl or ltr
  80     template_env.globals['fetch_messages'] = messages.fetch_messages
  81     template_env.globals['app_config'] = app.app_config
  82     template_env.globals['global_config'] = app.global_config
  83     template_env.globals['version'] = _version.__version__
  84     template_env.globals['auth'] = app.auth
  85     template_env.globals['is_rtl'] = is_rtl(locale)
  86     template_env.filters['urlencode'] = url_quote_plus
  87
  88     # add human readable fuzzy date time
  89     template_env.globals['timesince'] = timesince
  90
  91     # allow for hooking up plugin templates
  92     template_env.globals['get_hook_templates'] = get_hook_templates
  93
  94     template_env.globals = hook_transform(
  95         'template_global_context', template_env.globals)
  96
  97     #### THIS IS TEMPORARY, PLEASE FIX IT
  98     ## Notifications stuff is not yet a plugin (and we're not sure it will be),
  99     ## but it needs to add stuff to the context.  This is THE WRONG WAY TO DO IT
 100     from mediagoblin import notifications
 101     template_env.globals['get_notifications'] = notifications.get_notifications
 102     template_env.globals[
 103         'get_notification_count'] = notifications.get_notification_count
 104     template_env.globals[
 105         'get_comment_subscription'] = notifications.get_comment_subscription
 106
 107     if exists(locale):
 108         SETUP_JINJA_ENVS[locale] = template_env
 109
 110     return template_env
 111
 112
 113 # We'll store context information here when doing unit tests
 114 TEMPLATE_TEST_CONTEXT = {}
 115
 116
 117 def render_template(request, template_path, context):
 118     """
 119     Render a template with context.
 120
 121     Always inserts the request into the context, so you don't have to.
 122     Also stores the context if we're doing unit tests.  Helpful!
 123     """
 124     template = request.template_env.get_template(
 125         template_path)
 126     context['request'] = request
 127     rendered_csrf_token = render_csrf_form_token(request)
 128     if rendered_csrf_token is not None:
 129         context['csrf_token'] = render_csrf_form_token(request)
 130
 131     # allow plugins to do things to the context
 132     if request.controller_name:
 133         context = hook_transform(
 134             (request.controller_name, template_path),
 135             context)
 136
 137     # More evil: allow plugins to possibly do something to the context
 138     # in every request ever with access to the request and other
 139     # variables.  Note: this is slower than using
 140     # template_global_context
 141     context = hook_transform(
 142         'template_context_prerender', context)
 143
 144     rendered = template.render(context)
 145
 146     if common.TESTS_ENABLED:
 147         TEMPLATE_TEST_CONTEXT[template_path] = context
 148
 149     return rendered
 150
 151
 152 def clear_test_template_context():
 153     global TEMPLATE_TEST_CONTEXT
 154     TEMPLATE_TEST_CONTEXT = {}
 155
 156
 157 class TemplateHookExtension(Extension):
 158     """
 159     Easily loop through a bunch of templates from a template hook.
 160
 161     Use:
 162       {% template_hook("comment_extras") %}
 163
 164     ... will include all templates hooked into the comment_extras section.
 165     """
 166
 167     tags = set(["template_hook"])
 168
 169     def parse(self, parser):
 170         includes = []
 171         expr = parser.parse_expression()
 172         lineno = expr.lineno
 173         hook_name = expr.args[0].value
 174
 175         for template_name in get_hook_templates(hook_name):
 176             includes.append(
 177                 parser.parse_import_context(
 178                     Include(Const(template_name), True, False, lineno=lineno),
 179                     True))
 180
 181         return includes