If data is cached and uptodate, do not use ajax rendering

README

@@ -108,7 +108,9 @@ The config dictonnary can contain the following keys:
 content of the dictionnary is described later,
 - `template`, the template in which to render the data sources, it
 will receive a variable named `data_sources` in its context
-containing property named after the `slug` field of each source.
+containing property named after the `slug` field of each source,
+- `accepted_http_status`, a list of integers giving the accepted HTTP status,
+	default is `[200]`.
 
 A source definition is a dictionnary containing the following keys:
     - `slug`, the field name to hold this source parsed value in the
@@ -164,7 +166,9 @@ A source definition is a dictionnary containing the following keys:
       present,
     - `user_context`, whether the user must be part of the cache key. For retro
       compatibility If authentication mechanism is OAuth2, it defaults to True
-      otherwise to False.
+      otherwise to False,
+    - `accepted_http_status`, a list of integers giving the accepted HTTP status,
+      default is taken from the renderer level.
 
 Exemple with the JSON parser
 ----------------------------

src/cmsplugin_blurp/cms_plugins.py

@@ -1,9 +1,12 @@
+import logging
+
+from django.conf import settings
 from django.utils.translation import ugettext_lazy as _
 
 from cms.plugin_pool import plugin_pool
 from cms.plugin_base import CMSPluginBase
 
-from . import models
+from . import models, utils
 
 class BlurpPlugin(CMSPluginBase):
     name = _('Blurp Plugin')
@@ -12,26 +15,18 @@ class BlurpPlugin(CMSPluginBase):
     render_template = ''
 
     def render(self, context, instance, placeholder):
-        renderer = instance.get_renderer()
-        request = context.get('request')
-        ajax = context.get('ajaxy', True) and renderer.config.get('ajax', False)
-        if not ajax:
-            self.render_template = renderer.render_template()
-            return renderer.render(context)
-        else:
-            request = context.get('request')
-            context['plugin_id'] = instance.id
-            context['ajax_refresh'] = renderer.config.get('ajax_refresh', 0)
-            if request.GET:
-                context['plugin_args'] = '?{0}'.format(request.GET.urlencode())
-            # hack alert !!
-            self.render_template = 'cmsplugin_blurp/ajax.html'
+        logger = logging.getLogger(__name__)
+        try:
+            slug = instance.name
+            template, context = utils.render_blurp(context, slug)
+            self.render_template = template
             return context
-
-
-
-
-
+        except Exception, e:
+            logger.exception('error while rendering blurp %s', slug)
+            if settings.TEMPLATE_DEBUG:
+                msg = 'error while rendering blurp %s: %s' % (slug, e)
+                self.render_template = 'cmsplugin_blurp/error.html'
+                return {'content': msg}
 
 
 plugin_pool.register_plugin(BlurpPlugin)

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)

src/cmsplugin_blurp/renderers/data_source.py

@@ -37,6 +37,7 @@ class Renderer(template.TemplateRenderer):
                      'timeout': 10, # optional default is 1, it cannot be less than 1
                      'refresh': 3600, # optional, default is taken from the renderer level
                      'limit': 0, # optional, default is taken from the renderer level
+                     'accepted_http_status': [200,400], # optional, default it taken from the renderer level
                   },
               ]
               'template_name': 'data_from_xyz.html'
@@ -51,9 +52,11 @@ class Renderer(template.TemplateRenderer):
               # not limited if it is 0
               # you can also override it in each source
               'limit': 0, # optional default is 0
+              'accepted_http_status': [200,400], # optional, default is [200]
            }
 
     '''
+    __sources = None
 
     @classmethod
     def check_config(cls, config):
@@ -78,12 +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:
@@ -100,6 +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
@@ -141,6 +158,8 @@ class Data(object):
         self.signature_key = source.get('signature_key')
         self.parser_type = source.get('parser_type', 'raw')
         self.content_type = source.get('content_type', self.MAPPING[self.parser_type])
+        self.accepted_http_status = source.get('accepted_http_status',
+                config.get('accepted_http_status', [200]))
         self.user_context = source.get('user_context',
                 config.get('user_context', self.auth_mech == 'oauth2'))
         pre_hash = 'datasource-{self.slug}-{self.url}-{self.limit}-' \
@@ -195,7 +214,8 @@ class Data(object):
                     allow_redirects=self.redirects,
                     timeout=self.timeout,
                     stream=True)
-            request.raise_for_status()
+            if request.status_code not in self.accepted_http_status:
+                request.raise_for_status()
             return request.raw, None
         except HTTPError:
             error = 'HTTP Error %s when loading URL %s for renderer %r' % (
@@ -271,6 +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

src/cmsplugin_blurp/templates/cmsplugin_blurp/ajax.html

@@ -7,13 +7,13 @@
         if ($ == undefined) {
           alert('jQuery is missing');
         } else {
-          var $container = $("#block-plugin-ajax-{{ plugin_id }}");
+          var $container = $("#block-plugin-ajax-{{ slug }}");
           var ajax_refresh = {{ ajax_refresh }};
           var exponential_refresh = ajax_refresh;
           var reload = function () {
             $container.removeClass('block-plugin-ajax-failed');
             $container.addClass('block-plugin-ajax-loading');
-            $.getJSON('{% url 'ajax_render' plugin_id=plugin_id %}{{ plugin_args|safe }}', function (result) {
+            $.getJSON('{% url 'ajax_render' slug=slug %}{{ plugin_args|safe }}', function (result) {
               $container.html(result.content);
               $container.removeClass('block-plugin-ajax-loading');
               if (ajax_refresh > 0) {
@@ -38,7 +38,7 @@
   </script>
 {% endaddtoblock %}
 
-<div id="block-plugin-ajax-{{ plugin_id }}" class='block-plugin-ajax block-plugin-ajax-loading'>
+<div id="block-plugin-ajax-{{ slug }}" class='block-plugin-ajax block-plugin-ajax-loading'>
   <div class="block-plugin-ajax-placeholder">{% trans "loading..." %}</div>
 </div>
 

src/cmsplugin_blurp/templatetags/blurp_tags.py

@@ -32,25 +32,22 @@ class RenderBlurp(Tag):
     )
 
 
-    def render_tag(self, context, name):
-        renderer = utils.resolve_renderer(name)
-        if not renderer:
-            return ''
-        template = renderer.render_template()
-        context = renderer.render(context)
+    def render_tag(self, context, slug):
+        context.push()
         try:
-            if not hasattr(template, 'render'):
-                template = template.Template(template)
-            return template.render(context)
-        except Exception, e:
-            logging.getLogger(__name__).exception('error while rendering %s',
-                    renderer)
-            msg = ''
-            if settings.TEMPLATE_DEBUG:
-                msg += 'error while rendering %s: %s' % (renderer, e)
-                msg = '<pre>%s</pre>' % escape(msg)
-            return msg
-
+            logger = logging.getLogger(__name__)
+            try:
+                template, context = utils.render_blurp(context, slug)
+                return template.render(context)
+            except Exception, e:
+                logger.exception('error while rendering blurp %s', slug)
+                msg = ''
+                if settings.TEMPLATE_DEBUG:
+                    msg += 'error while rendering blurp %s: %s' % (slug, e)
+                    msg = '<pre>%s</pre>' % escape(msg)
+                return msg
+        finally:
+            context.pop()
 
 @register.tag
 class BlurpNode(Tag):
@@ -60,9 +57,11 @@ class BlurpNode(Tag):
             Argument('name'),
             blocks=[('endblurp', 'nodelist')])
 
-    def render_tag(self, context, name, nodelist):
+    def render_tag(self, context, slug, nodelist):
         context.push()
-        utils.insert_blurp_in_context(name, context)
-        output = self.nodelist.render(context)
-        context.pop()
-        return output
+        try:
+            utils.insert_blurp_in_context(slug, context)
+            output = self.nodelist.render(context)
+            return output
+        finally:
+            context.pop()

src/cmsplugin_blurp/urls.py

@@ -3,7 +3,7 @@ from django.conf.urls import patterns, url
 from . import views
 
 urlpatterns = patterns('',
-                  url(r'^block-plugin-async/(?P<plugin_id>\d+)/$', 
+                  url(r'^block-plugin-async/(?P<slug>\w+)/$', 
                       views.ajax_render,
                       name='ajax_render')
               )

src/cmsplugin_blurp/utils.py

@@ -1,5 +1,8 @@
+import logging
+
 from django.utils.importlib import import_module
 from django.utils.translation import ugettext_lazy as _
+from django.template.loader import get_template
 
 from . import app_settings
 
@@ -34,3 +37,26 @@ def insert_blurp_in_context(name, context):
         if not renderer:
             return ''
         return renderer.render(context)
+
+def render_blurp(context, slug, ajax=True):
+    logger = logging.getLogger(__name__)
+    renderer = resolve_renderer(slug)
+    if not renderer:
+        logger.warning('renderer %s does not exist', slug)
+        return None, None
+    # Ajax rendering is canceled in the ajax view
+    ajax = ajax and renderer.use_ajax(context)
+    if ajax:
+        request = context.get('request')
+        context['slug'] = renderer.slug
+        context['ajax_refresh'] = renderer.config.get('ajax_refresh', 0)
+        if request.GET:
+            context['plugin_args'] = '?{0}'.format(request.GET.urlencode())
+        # hack alert !!
+        template = get_template('cmsplugin_blurp/ajax.html', context)
+    else:
+        template = renderer.render_template()
+        if not hasattr(template, 'render'):
+            template = template.Template(template)
+        context = renderer.render(context)
+    return template, context

src/cmsplugin_blurp/views.py

@@ -2,20 +2,27 @@ import json
 import logging
 
 from django.http import HttpResponse
-from django.template import RequestContext, loader
-from django.shortcuts import get_object_or_404
+from django.template import RequestContext
+from django.utils.html import escape
+from django.conf import settings
 
-from cms.models import CMSPlugin
+from . import utils
 
 logger = logging.getLogger(__name__)
 
-def ajax_render(request, plugin_id):
+def ajax_render(request, slug):
     context = RequestContext(request)
-    context['ajaxy'] = False
-    plugin = get_object_or_404(CMSPlugin, pk=plugin_id)
-    rendered = plugin.render_plugin(context)
-    # use another template to render accumulated js and css declarations from sekizai
-    content = loader.render_to_string('cmsplugin_blurp/sekizai_render.html',
-            {'content': rendered}, context)
-    return HttpResponse(json.dumps({'content': content}))
+    template, context = utils.render_blurp(context, slug, ajax=False)
+    result = {}
+    try:
+        template, context = utils.render_blurp(context, slug)
+        result['content'] = template.render(context)
+    except Exception, e:
+        logger.exception('error while rendering blurp %s', slug)
+        msg = ''
+        result['error'] = msg
+        if settings.TEMPLATE_DEBUG:
+            msg += 'error while rendering blurp %s: %s' % (slug, e)
+            result['content'] = '<pre>%s</pre>' % escape(msg)
+    return HttpResponse(json.dumps(result))