Added custom template loader to CMS in order to enable {% include %} and {% import %} in jinja temp…

sitescripts/cms/sources.py

Index: sitescripts/cms/sources.py
===================================================================
--- a/sitescripts/cms/sources.py
+++ b/sitescripts/cms/sources.py
@@ -18,6 +18,7 @@
 import sys, os, subprocess, zipfile, json, urlparse, codecs
 from StringIO import StringIO
 from ConfigParser import SafeConfigParser
+import jinja2
 
 class Source:
   def resolve_link(self, url, locale):
@@ -166,6 +167,9 @@
   def read_template(self, template):
     return self.read_file(self.template_filename(template))
 
+  def get_template_loader(self):
+    return SourceLoader(self)
+
   #
   # Include helpers
   #
@@ -259,3 +263,13 @@
           do_list(path, relpath + filename + "/")
     do_list(self.get_path(subdir), "")
     return result
+
+class SourceLoader(jinja2.BaseLoader):

[Wladimir Palant, 2013/12/11 18:46:02]

I don't think that Jinja-specific functionality belongs into sources.py - this
should be a private class of TemplateConverter, inside converters.py.

+  def __init__(self, source):
+    self.source = source
+
+  def get_source(self, environment, template):
+    try:
+      return self.source.read_file(template + '.tmpl'), None, None

[Wladimir Palant, 2013/12/11 18:46:02]

I think this should be self.source.read_include(template, "tmpl") - we want to
use paths relative to the includes directory.

[Sebastian Noack, 2013/12/11 22:20:14]

I've already addressed that, but I would like to undo that change, because the
template loader isn't only used for includes but also for imports and extends
(template inheritance). While you can argue whether imports are some kind of
includes, extends definetly aren't. Templates you extend from can and often will
also be rendered on their own. Beside that putting templates into the includes
subdir will also make them available for <? include ... ?>. But there is no
point in including templates that behave as library (only provide variables and
macros that can be imported) or that exist in order to extend them. What do you
think?

[Wladimir Palant, 2013/12/12 07:16:54]

Yes, you are right. We might want to extend the default template meaning that we
will have to address a template in the templates folder. Ok, let's have the
paths relative to the root here.

Nevertheless, the template with the team data should be located in the includes
directory.

+    except Exception:
+      raise jinja2.TemplateNotFound(template)