From f3be97ef4d4ce829bdf69b1fe84516cf0b977272 Mon Sep 17 00:00:00 2001
From: Timo Stollenwerk <timo@rudolf.(none)>
Date: Sun, 30 Oct 2011 10:10:55 +0100
Subject: [PATCH] Comments viewlet howto updated.

---
 .../howto_override_comments_viewlet.txt       | 78 +++++++++++++++----
 1 file changed, 61 insertions(+), 17 deletions(-)

diff --git a/docs/source/howtos/howto_override_comments_viewlet.txt b/docs/source/howtos/howto_override_comments_viewlet.txt
index f766799..0fd424b 100644
--- a/docs/source/howtos/howto_override_comments_viewlet.txt
+++ b/docs/source/howtos/howto_override_comments_viewlet.txt
@@ -2,27 +2,51 @@
 How to override plone.app.discussion's comments viewlet
 ================================================================================
 
+This document explains how to override the plone.app.discussion comments 
+viewlet that controls the way existing comments are displayed.
+
+There are three different ways to override plone.app.discussion's comments 
+viewlet: through-the-web, on the file system with z3c.jbot, and by overriding 
+the comments viewlet class on the file system. 
+
+Overriding the comments viewlet template throught-the-web is the quick and 
+dirty approach. Using z3c.jbot is the recommended approach if you just want to 
+override the comments viewlet template. If you want full control over the 
+comments viewlet class, for instance if you want to add/customize view methods,
+overriding the comments viewlet class on the file system is the recommended
+approach.
+
+
 Override the comments template through-the web
 ----------------------------------------------
 
-    * go to the ZMI
-    * click on portal_view_customizations
-    * customize plone.comments (plone.app.discussion.interfaces.IDiscussionLayer)
+Overriding the comments template through-the web is the easiest way to 
+customize the comments viewlet::
+
+  * Go to the ZMI (http://localhost:8080/Plone/manage_main)
+  * Click on "portal_view_customizations"
+  * Customize plone.comments (plone.app.discussion.interfaces.IDiscussionLayer)
 
 
 Override the comments template with z3c.jbot on the file system
 ---------------------------------------------------------------
 
-http://pypi.python.org/pypi/z3c.jbot
+The easiest way to override the comments template on the file
+system is with `z3c.jbot`_. `z3c.jbot`_ allows you to override any
+Plone template just by putting a file in a specific directory.
 
-setup.py::
+`z3c.jbot`:: http://pypi.python.org/pypi/z3c.jbot
+
+Add z3c.jbot to the dependencies of your package by adding a
+line to your setup.py file::
 
     install_requires=[
         ...
         'z3c.jbot',
     ],
 
-configure.zcml::
+Register an overrides directory where you can put your file
+overrides in your configure.zcml file::
 
     <include package="z3c.jbot" file="meta.zcml" />
 
@@ -32,51 +56,66 @@ configure.zcml::
 
 Replace <layer> with a custom browserlayer of your package.
 
-Create template directory::
+Create the template directory we just registered::
 
     $ mkdir overrides
 
-Copy comments viewlet template to overrides directory::
+Copy the comments viewlet template we want to override to the
+overrides directory we just created and registered::
     
     $ cp ../parts/omelette/plone/app/discussion/browser/comments.pt overrides/plone.app.discussion.browser.comments.pt
 
-Restart your Plone instance and you can start to customize your copy of the comments viewlet.
+Restart your Plone instance and you can start to customize 
+the plone.app.discussion.browser.comments.pt we just created.
 
 
 Override the comments viewlet class on the file system
 ------------------------------------------------------
 
-interfaces.py::
+Overriding/subclassing the comments viewlet class is allows you not only to
+override the comments viewlet template, but also the comment viewlets view 
+methods. There are many ways to override components in Plone with the Zope
+Component Architecture (ZCA), which is beyond the scope of this howto.
+
+We are going to register our own browserlayer
+
+First we define our browser layer in interfaces.py::
 
     from plone.app.discussion.interfaces import IDiscussionLayer
 
     class IMyDiscussionLayer(IDiscussionLayer):
-        """Marker interface for browser layer
+        """Marker interface for a custom plone.app.discussion browser layer
         """
 
-profiles/default/browserlayer.xml::
+Next, we register the browserlayer in our generic setup (GS) setup in the
+profiles/default/browserlayer.xml file::
 
     <?xml version="1.0"?>
     <layers>
-      <layer name="my.discussion"
+      <layer name="my.discussionlayer"
              interface="my.discussion.interfaces.IMyDiscussionLayer" />
     </layers>
 
 
+
+
 configure.zcml::
 
   <!-- Override plone.app.discussion's comments viewlet -->
   <browser:viewlet
     name="plone.comments"
     for="Products.CMFCore.interfaces.IContentish"
-    layer="plone.app.discussion.interfaces.IDiscussionLayer"
+    layer="my.discussion.interfaces.IDiscussionLayer"
     manager="plone.app.layout.viewlets.interfaces.IBelowContent"
     view="plone.app.layout.globals.interfaces.IViewView"
     class=".comments.CommentsViewlet"
     permission="zope2.View"
     />
 
-comments.py::
+note: Note that we override the comments viewlet by using the my.discussion.interfaces.IMyDiscussionLayer browser layer and not the default plone.app.discussion.interfaces.IDiscussionLayer browser layer.
+
+Once we registered the custom discussion browser layer and the viewlet, we can create a
+comments.py file with our custom version of the comments viewlet::
 
     from Products.Five.browser.pagetemplatefile import ViewPageTemplateFile
     
@@ -95,8 +134,8 @@ comments.py::
             else:
                 return "%s/memberhome/%s" % (self.context.portal_url(), username)
 
-
-comment.pt::
+To override the comments viewlet template, we create a comment.pt file in the
+same directory and copy the contents from::
 
     ...
 
@@ -104,14 +143,19 @@ comment.pt::
 Override the comments viewlet Javascript
 ----------------------------------------
 
+Overriding the comments viewlet javascript works just like overriding the
+comments viewlet. We register the javascript file for our custom browser
+layer and remove the existing javascript file in 
 profiles/default/jsregistry.xml::
 
     <?xml version="1.0"?>
     <object name="portal_javascripts">
+     <!-- Remove plone.app.discussion comments javascript -->
      <javascript
          id="++resource++plone.app.discussion.javascripts/comments.js"
          remove="True"
          />
+     <!-- Register a custom version of the plone.app.discussion javascript -->
      <javascript
          id="++resource++example.myaddonproduct.javascripts/comments.js" />
     </object>