From cb8b7cd2f42e7f8837f8880b07ecc0e90a0334cd Mon Sep 17 00:00:00 2001
From: Benjamin Dauvergne <bdauvergne@entrouvert.com>
Date: Mon, 26 Jan 2015 15:12:10 +0100
Subject: [PATCH] If data is cached and uptodate, do not use ajax rendering

---
 src/cmsplugin_blurp/renderers/base.py        |  3 ++
 src/cmsplugin_blurp/renderers/data_source.py | 44 +++++++++++++++++---
 src/cmsplugin_blurp/utils.py                 |  2 +-
 3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/src/cmsplugin_blurp/renderers/base.py b/src/cmsplugin_blurp/renderers/base.py
index ae5e85b..5c4f327 100644
--- a/src/cmsplugin_blurp/renderers/base.py
+++ b/src/cmsplugin_blurp/renderers/base.py
@@ -40,3 +40,6 @@ class BaseRenderer(object):
     def render_template(self):
         '''Return a template path or a Template object'''
         pass
+
+    def use_ajax(self, context):
+        return self.config.get('ajax', False)
diff --git a/src/cmsplugin_blurp/renderers/data_source.py b/src/cmsplugin_blurp/renderers/data_source.py
index 183ad6a..5a7a765 100644
--- a/src/cmsplugin_blurp/renderers/data_source.py
+++ b/src/cmsplugin_blurp/renderers/data_source.py
@@ -56,6 +56,7 @@ class Renderer(template.TemplateRenderer):
            }
 
     '''
+    __sources = None
 
     @classmethod
     def check_config(cls, config):
@@ -80,12 +81,17 @@ class Renderer(template.TemplateRenderer):
                    yield 'missing signature_key string'
 
     def get_sources(self, context):
-        for source in self.config['sources']:
-            slug = '{0}.{1}'.format(self.slug, source['slug'])
-            data = Data(slug, self.config, source, context)
-            yield source['slug'], data
-        if settings.TEMPLATE_DEBUG:
-            yield 'blurp_debug__', '\n'.join(self.debug_content(context))
+        if self.__sources is None:
+            sources = []
+            for source in self.config['sources']:
+                slug = '{0}.{1}'.format(self.slug, source['slug'])
+                data = Data(slug, self.config, source, context)
+                sources.append((source['slug'], data))
+            if settings.TEMPLATE_DEBUG:
+                sources.append(('blurp_debug__',
+                    '\n'.join(self.debug_content(context))))
+            self.__sources = sources
+        return self.__sources
 
     def debug_content(self, context):
         try:
@@ -102,6 +108,15 @@ class Renderer(template.TemplateRenderer):
             except Exception, e:
                 yield u'slug {0!r}: pformat failed {1!r}'.format(slug, e)
 
+    def use_ajax(self, context):
+        '''Only use ajax if some content is not cached'''
+        if super(Renderer, self).use_ajax(context):
+            for source in self.get_sources():
+                if not source.content_is_cached():
+                    return False
+        else:
+            return False
+
     def render(self, context):
         for slug, source in self.get_sources(context):
             context[slug] = source
@@ -276,6 +291,23 @@ class Data(object):
     UPDATE_THREADS = {}
     CONDITIONS = {}
 
+    def content_is_cached(self, ignore_stale_content=True):
+        '''Test if some content is in cache'''
+        if self.__content is self.__CACHE_SENTINEL:
+            content, until = cache.get(self.key, (self.__CACHE_SENTINEL, None))
+            if not ignore_stale_content:
+                self.__content = content
+            if until is not None and ignore_stale_content and until < self.now:
+                return False
+            if self.refresh <= 0:
+                return False
+            if self.request and 'updatecache' in self.request.GET:
+                return False
+            self.__content = content
+            return True
+        else:
+            return True
+
     def get_content(self):
         if self.__content is not self.__CACHE_SENTINEL:
             return self.__content
diff --git a/src/cmsplugin_blurp/utils.py b/src/cmsplugin_blurp/utils.py
index d6337fd..2b4c47e 100644
--- a/src/cmsplugin_blurp/utils.py
+++ b/src/cmsplugin_blurp/utils.py
@@ -45,7 +45,7 @@ def render_blurp(context, slug, ajax=True):
         logger.warning('renderer %s does not exist', slug)
         return None, None
     # Ajax rendering is canceled in the ajax view
-    ajax = ajax and renderer.config.get('ajax', False)
+    ajax = ajax and renderer.use_ajax(context)
     if ajax:
         request = context.get('request')
         context['slug'] = renderer.slug