Enabled configurable plugin caching for CMS 3.3.0+ installations (#407)

* Re-enable caching for CMS 3.3.0+ installations

* Updated for review comments

* Added ability to set cache_duration for plugin on CMS 3.3.0+

* Fixed tox.ini

* Updated for review comments

aldryn_newsblog/cms_plugins.py

@@ -2,14 +2,18 @@
 
 from __future__ import unicode_literals
 
+from distutils.version import LooseVersion
 from django.utils.translation import ugettext_lazy as _
 
+from cms import __version__ as cms_version
 from cms.plugin_base import CMSPluginBase
 from cms.plugin_pool import plugin_pool
 
 from . import models, forms
 from .utils import add_prefix_to_path, default_reverse
 
+CMS_GTE_330 = LooseVersion(cms_version) >= LooseVersion('3.3.0')
+
 
 class TemplatePrefixMixin(object):
 
@@ -27,11 +31,39 @@ class NewsBlogPlugin(TemplatePrefixMixin, CMSPluginBase):
     module = 'News & Blog'
 
 
+class AdjustableCacheMixin(object):
+    """
+    For django CMS < 3.3.0 installations, we have no choice but to disable the
+    cache where there is time-sensitive information. However, in later CMS
+    versions, we can configure it with `get_cache_expiration()`.
+    """
+    if not CMS_GTE_330:
+        cache = False
+
+    def get_cache_expiration(self, request, instance, placeholder):
+        return getattr(instance, 'cache_duration', 0)
+
+    def get_fieldsets(self, request, obj=None):
+        """
+        Removes the cache_duration field from the displayed form if we're not
+        using django CMS v3.3.0 or later.
+        """
+        fieldsets = super(AdjustableCacheMixin, self).get_fieldsets(request, obj=None)
+        if CMS_GTE_330:
+            return fieldsets
+
+        field = 'cache_duration'
+        for fieldset in fieldsets:
+            new_fieldset = [
+                item for item in fieldset[1]['fields'] if item != field]
+            fieldset[1]['fields'] = tuple(new_fieldset)
+        return fieldsets
+
+
 @plugin_pool.register_plugin
-class NewsBlogArchivePlugin(NewsBlogPlugin):
+class NewsBlogArchivePlugin(AdjustableCacheMixin, NewsBlogPlugin):
     render_template = 'aldryn_newsblog/plugins/archive.html'
     name = _('Archive')
-    cache = False
     model = models.NewsBlogArchivePlugin
     form = forms.NewsBlogArchivePluginForm
 
@@ -112,10 +144,9 @@ def render(self, context, instance, placeholder):
 
 
 @plugin_pool.register_plugin
-class NewsBlogLatestArticlesPlugin(NewsBlogPlugin):
+class NewsBlogLatestArticlesPlugin(AdjustableCacheMixin, NewsBlogPlugin):
     render_template = 'aldryn_newsblog/plugins/latest_articles.html'
     name = _('Latest Articles')
-    cache = False
     model = models.NewsBlogLatestArticlesPlugin
     form = forms.NewsBlogLatestArticlesPluginForm
 
@@ -127,11 +158,11 @@ def render(self, context, instance, placeholder):
 
 
 @plugin_pool.register_plugin
-class NewsBlogRelatedPlugin(NewsBlogPlugin):
+class NewsBlogRelatedPlugin(AdjustableCacheMixin, NewsBlogPlugin):
     render_template = 'aldryn_newsblog/plugins/related_articles.html'
     name = _('Related Articles')
-    cache = False
     model = models.NewsBlogRelatedPlugin
+    form = forms.NewsBlogRelatedPluginForm
 
     def get_article(self, request):
         if request and request.resolver_match:

aldryn_newsblog/forms.py

@@ -20,7 +20,7 @@ def __init__(self, *args, **kwargs):
 class NewsBlogArchivePluginForm(AutoAppConfigFormMixin, forms.ModelForm):
     class Meta:
         model = models.NewsBlogArchivePlugin
-        fields = ['app_config']
+        fields = ['app_config', 'cache_duration']
 
 
 class NewsBlogArticleSearchPluginForm(AutoAppConfigFormMixin, forms.ModelForm):
@@ -52,9 +52,17 @@ class NewsBlogLatestArticlesPluginForm(AutoAppConfigFormMixin,
                                        forms.ModelForm):
     class Meta:
         model = models.NewsBlogLatestArticlesPlugin
-        fields = ['app_config', 'latest_articles', 'exclude_featured']
+        fields = [
+            'app_config', 'latest_articles', 'exclude_featured',
+            'cache_duration'
+        ]
 
 
 class NewsBlogTagsPluginForm(AutoAppConfigFormMixin, forms.ModelForm):
     class Meta:
         fields = ['app_config']
+
+
+class NewsBlogRelatedPluginForm(forms.ModelForm):
+    class Meta:
+        fields = ['cache_duration']

aldryn_newsblog/migrations/0013_auto_20160623_1703.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.6 on 2016-06-23 21:03
+from __future__ import unicode_literals
+
+import app_data.fields
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('aldryn_newsblog', '0012_auto_20160503_1626'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='newsblogarchiveplugin',
+            name='cache_duration',
+            field=models.PositiveSmallIntegerField(default=0, help_text="The maximum duration (in seconds) that this plugin's contentshould be cached. Values between 5 minutes (300) and one day (84600) recommended)."),
+        ),
+        migrations.AddField(
+            model_name='newsbloglatestarticlesplugin',
+            name='cache_duration',
+            field=models.PositiveSmallIntegerField(default=0, help_text="The maximum duration (in seconds) that this plugin's contentshould be cached. Values between 5 minutes (300) and one day (84600) recommended)."),
+        ),
+        migrations.AddField(
+            model_name='newsblogrelatedplugin',
+            name='cache_duration',
+            field=models.PositiveSmallIntegerField(default=0, help_text="The maximum duration (in seconds) that this plugin's contentshould be cached. Values between 5 minutes (300) and one day (84600) recommended)."),
+        ),
+        migrations.AlterField(
+            model_name='newsblogconfig',
+            name='app_data',
+            field=app_data.fields.AppDataField(default='{}', editable=False),
+        ),
+    ]

aldryn_newsblog/models.py

@@ -248,6 +248,21 @@ def get_edit_mode(self, request):
             request.toolbar.edit_mode)
 
 
+class AdjustableCacheModelMixin(models.Model):
+    # NOTE: This field shouldn't even be displayed in the plugin's change form
+    # if using django CMS < 3.3.0
+    cache_duration = models.PositiveSmallIntegerField(
+        default=0,  # not the most sensible, but consistent with older versions
+        blank=False,
+        help_text=_(
+            "The maximum duration (in seconds) that this plugin's content "
+            "should be cached.")
+    )
+
+    class Meta:
+        abstract = True
+
+
 class NewsBlogCMSPlugin(CMSPlugin):
     """AppHookConfig aware abstract CMSPlugin class for Aldryn Newsblog"""
     # avoid reverse relation name clashes by not adding a related_name
@@ -265,7 +280,8 @@ def copy_relations(self, old_instance):
 
 
 @python_2_unicode_compatible
-class NewsBlogArchivePlugin(PluginEditModeMixin, NewsBlogCMSPlugin):
+class NewsBlogArchivePlugin(PluginEditModeMixin, AdjustableCacheModelMixin,
+                            NewsBlogCMSPlugin):
     # NOTE: the PluginEditModeMixin is eventually used in the cmsplugin, not
     # here in the model.
     def __str__(self):
@@ -403,7 +419,9 @@ def __str__(self):
 
 
 @python_2_unicode_compatible
-class NewsBlogLatestArticlesPlugin(PluginEditModeMixin, NewsBlogCMSPlugin):
+class NewsBlogLatestArticlesPlugin(PluginEditModeMixin,
+                                   AdjustableCacheModelMixin,
+                                   NewsBlogCMSPlugin):
     latest_articles = models.IntegerField(
         default=5,
         help_text=_('The maximum number of latest articles to display.')
@@ -447,7 +465,8 @@ def __str__(self):
 
 
 @python_2_unicode_compatible
-class NewsBlogRelatedPlugin(PluginEditModeMixin, CMSPlugin):
+class NewsBlogRelatedPlugin(PluginEditModeMixin, AdjustableCacheModelMixin,
+                            CMSPlugin):
     # NOTE: This one does NOT subclass NewsBlogCMSPlugin. This is because this
     # plugin can really only be placed on the article detail view in an apphook.
     cmsplugin_ptr = models.OneToOneField(