Issue 2179 - [cms] Give Jinja2 templates a way to set global parameters

cms/converters.py

Index: cms/converters.py
===================================================================
--- a/cms/converters.py
+++ b/cms/converters.py
@@ -289,17 +289,17 @@ class TemplateConverter(Converter):
         extensions=["jinja2.ext.do",],
         autoescape=True
     )
     self._env.filters.update(filters)
     self._env.globals.update(globals)
 
   def get_html(self, source):
     template = self._env.from_string(source)
-    return template.render(self._params)
+    return template.render(self._params, params=self._params)

[Sebastian Noack, 2015/03/20 09:44:36]

Note that modifying the params dict won't modify the current context. Hence
following template would output the old "title" passed to the template if any.

  {% do params.update(title="foo") %}
  ...
  {{ title }}

So how about:

  module = template.make_module(self._params)
  for key, value in module.__dict__.iteritems():
    if not key.startswith("_"):
      self._params[key] = value
  return unicode(module)

That way you can just keep using the regular {% set %} statement to set
variables. And variables set in the template will be copied to the self._params.

[Wladimir Palant, 2015/03/20 15:31:39]

The complication here: only variables set at top level will work. So setting
conditionally for example is extremely awkward. But - fine with me, I managed to
get it working.

I'm somewhat concerned about dumping every exported variable into self._params
but I don't see a better solution right now.

[Sebastian Noack, 2015/03/20 15:53:18]

I think it's the best we can realistically do.

 
   def translate(self, default, name, comment=None):
     # Note: We currently ignore the comment, it is only relevant when
     # generating the master translation.
     localedata = self._params["localedata"]
     return jinja2.Markup(self.localize_string(name, default, localedata, html_escapes))
 
   def get_string(self, name, page):