Docserver: Factor SamplesModel out of SamplesDataSource

chrome/common/extensions/docs/server2/template_renderer.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from data_source_registry import CreateDataSources
 from third_party.handlebar import Handlebar
 from url_constants import GITHUB_BASE, EXTENSIONS_SAMPLES
 
 
 class TemplateRenderer(object):
@@ skipping 20 matching lines @@
     render_context = self._CreateDataSources(request)
     if data_sources is not None:
       render_context = dict((name, d) for name, d in render_context.iteritems()
                             if name in data_sources)
     render_context.update({
       'apps_samples_url': GITHUB_BASE,
       'base_path': self._server_instance.base_path,
       'extensions_samples_url': EXTENSIONS_SAMPLES,
       'static': self._server_instance.base_path + 'static',
     })
     if additional_context:

[ahernandez, 2014/08/05 19:15:53]

This is a pretty insignificant change, but I couldn't resist doing it while I
was in here.

[not at google - send to devlin, 2014/08/05 19:59:18]

it's actually a bit dangerous doing this, because the {} in the
additional_context={} is global, not scoped to each function. so if you were
ever to modify additional_context - which you don't, but who knows in the future
- that modification would persist. I've seen some very subtle bugs caused by
this behaviour so basically I just always set it to None, though if you *really*
want to inline it you could do

render_context.update(additional_context or {})

       render_context.update(additional_context)
     render_data = template.Render(render_context)
     return render_data.text, render_data.errors
 
   def _CreateDataSources(self, request):
     server_instance = self._server_instance
     data_sources = CreateDataSources(server_instance, request=request)
-    data_sources.update({
-      'samples': server_instance.samples_data_source_factory.Create(request),
-    })

[not at google - send to devlin, 2014/08/05 16:04:25]

you can delete more code than this. in fact I'd just inline _CreateDataSources
at the call site, it's all-but-1-line.

     return data_sources