[Zope-PTK] CMF some basic Q

[Jeffrey P Shell]

On 3/12/01 11:48 AM, "Norman Khine" <khine@bmpublications.co.uk> wrote:

> Hello,
> Following the set up of CMF1.0beta on zope 2.3.1b1, I am finding it to be a
> first class application and am hoping to learn more about it. What I am
> trying to figure out is as discussed in the
> http://cmf.zope.org/doc/ReviewerGuide customising skins, is that I would
> like to create a skin based on my own requrements.
> 
> Can someone please tell me how to create my own skins or if there are any
> particular steps needed to be taken?
> Am I correct to assume that the /custom folder in the ZMI is where these
> skins are built? If thats true, do I have to create seperate subfolders ie
> for images, content control etc etc...?
> As a simple example I tried to change the logo.png, so what I did was to go
> to the Image folder click on logo.png then click on Customize which in turn
> creates a copy of logo.png in the customs folder, I then Browse and get the
> image I want to place and Uploaded, Save the changes and then do a view.
> This is where the problem happens, when viewing I am unable to see anything,
> it just gives an outline of the image.
> Can you please direct me in the right direction as to how one is able to
> create their own skins
> Thanks

The following document is unfinished (and unposted), but should be enough to
tell you what you need.  Hopefully this document will be finished this week.
--
Skinning Portals

 About this document

  This document is an overview of the concept of *skinning*, one of
  the new techniques used in the CMF to allow customization.  This
  document assumes familiarity with Zope concepts such as DTML and the
  Zope Find tool.

 About the skins tool

  In the Zope CMF (Content Management Framework), a new concept has
  been introduced called *Tools*.  These tools perform services for
  content objects, letting the content objects be all about the
  content they represent.  One of these tools is the Skins Tool,
  *portal_skins*.  The skins tool moves the site-specific behavior
  away from the objects in the system, allowing a high degree of
  customization without requiring changes be made to the core classes
  of objects being used.

 The problems it solves

  Many Zope classes written in Python have direct links to their
  *management screens*, which ties objects too closely with their
  views.  Sometimes ZClasses can be used with Python classes as their
  base, putting all of the logic associated with an object in the base
  and all of the views as DTML methods in the ZClass.  But this runs
  into distribution problems: typically, a CMF developer would
  customize the views in a ZClass for their site.  But when a new CMF
  release was issued, their changes stood a good chance of being
  overwritten.

  So the problems that needed to be solved were:

   o Views of an object needed to be separated from the object.

   o The default views should be easy to update and distribute in the
     core product without affecting CMF Users customizations.

   o CMF Users shouldn't perform their customizations on the default set
     of views, but should have an easy way to customize and override.

   o Allowing multiple skins to coexist.  This gives quite a few
     benefits, including the ability to do internationalization of
     sites.

 What's in the skins tool

  So how does the Skins Tool solve these problems?  There are a few
  things that come together to form a skin:

   A definition of layers -- A proper skin is a definition of layers.

   What those layers are -- That definition of layers is a list of
     folderish objects containing DTML, Images, and Properties (or
     folders defining properties).  A skin named 'blue' might define
     its layers as 'blue, basic_css, general'.  This means that name
     lookup for something like 'standard_html_header' looks first in
     'blue', then 'basic_css', and then 'general' when the skin 'blue'
     is active.

     There are two types of places these names can come from by
     default:

      o FileSystem based default -- This is how the distribution
        problem is solved.  These are special objects that represent a
        view onto DTML, Properties, and Images that are stored on the
        file system in the CMF product.  The important thing here is
        that *they cannot be changed through the web*.  Updates to the
        CMF Product will replace these files, so it's important that
        they don't get changed.  These show up as *locked items*,
        reflecting that the user cannot change them.

      o Custom folders -- These are normal Zope folder objects that
        can contain normal DTML Methods and other objects.  Updating
        the CMF product won't touch what's in these folders.  And
        there's a special trick that the FileSystem based objects
        perform: they have a *customize* action that lets you copy the
        source of a FileSystem based object into any of the custom
        folders in the skins tool.

  The rest of this document explains in greater detail how you use
  these facilities to start customizing your CMF site.

 How to start skinning

  Looking deeper at the skins tool

   *This section assumes that you've already set up a CMF Site
   instance and are in the Zope Management Interface (ZMI)*

   It's time to look deeper at the skins tool to learn a little more
   about what's in it by default.  Go to the 'portal_skins' object in
   your CMF Site in the Zope Management Interface (ZMI).  In the
   default view, 'contents', you should see about seven or eight
   folders depending on your setup and the configuration of the CMF.
   Most of the folders have little green locks on them.  These are
   *Filesystem Directory View* objects.  They and their contents
   cannot be changed through the ZMI.  By default, there is one normal
   Zope folder in the skins tool, 'custom'.  This is where we'll start
   making our customizations.

   By clicking on the 'Properties' tab of the 'portal_skins' object,
   you'll see how skins are actually configured.  By default, there
   are three skins: *Basic*, *No CSS*, and *Nouvelle*.  A skin is made
   by layering different folders in the skins tool together.  In the
   'Layers' column in the skin selections area of the properties page
   are the comma separated lists of folders, in the order the lookup
   happens in for that skin selection.

  Looking at the default folders

   There's a default base of FileSystem DirectoryView objects that
   are installed in the skins tool by default.  This section covers
   what's inside.

   **Images** -- This folder only contains non-icon images that are
   used in the default skins.

   **content** -- This folder contains skinned DTML Methods and icons
   for the default set of Content objects (from the CMFDefault
   package).  These are for things like Document, File, etc..., as
   well as some common DTML Methods for all content objects, such as
   metadata editing forms and forms that support the default workflow
   configuration.

   **control** -- This folder contains DTML Methods acting as some
   common control scripts.  Examples of this are *folder_copy*, a
   wrapper around the default copy method of Folders.

   **custom** -- A regular Zope folder to start doing customizations
   in.  You can add other folders in the skins tool as well, but
   you'll likely start off here.

   **generic** -- The generic look and feel of the site.  This is
   where you'll find things like the default 'standard_html_header'
   and 'actions_box' DTML methods, as well as the DTML Methods used
   for the 'reconfigure portal' page.  The default style sheet setup
   (used in the skin *basic*) also lives here.

   **no_css** -- Used by the *No CSS* skin, this folder contains a
   file system properties object that disables the style sheet
   normally used in the skins.

   **nouvelle** -- Used by the *Nouvelle* skin, this folder contains a
   'nouvelle_stylesheet', and a filesystem properties object that
   supplies the values used in 'nouvelle_stylesheet'.

   **topic** -- If you have CMF Topic installed, you should have a
   'topic' folder as well.  This contains Topic object specific views.

   Hopefully the above can be used as a guide to help you find what
   you want or need to customize for your site.  Some general rules
   I've used for locating content is:

   o Use *ZopeFind*.  The 'Find' tab in Zope can be very helpful.
     From the 'portal_skins' tool, do a find for the item you want to
     customize, such as 'standard_html_header'.

   o Read 'standard_html_header' and 'standard_html_footer' enough to
     understand the different page components they're using.  You may
     not need to customize either of these much at first.  But you
     will need to know the named objects they're looking for.

   o Get to know the general purposes of the default folders in the
     skins tool.  Do some clicking around and look at the different
     DTML Methods.  After a while, you start noticing some patterns
     and remembering which ones are complete pages and which are
     components to use in those pages.

  Doing a simple customization

   Let's do a relatively simple customization.  If you're in a site
   that doesn't have any news items yet, the default news box on the
   Portal's front page says "No news is no news" by default.  Let's
   say we want to change that to say "There is nothing new under the
   sun".  The first step is finding the right thing to customize.
   Since that news box isn't really bound to a particular content
   object, it's safe to assume it's part of the 'generic' folder.  If
   you look in 'portal_skins/generic', there are a couple of DTML
   Methods with the name news in them.  Select *news_box* and see what
   comes up.  Instead of the normal DTML Method edit form, you'll get
   a grey box with the source code.  Above the box is the 'Customize'
   action form containing a pop-up list of folders available to
   customize to.  If you haven't added any new folders to the
   'portal_skins' tool, the default (and only) option should be
   *custom*.  So, with 'custom' selected, click *Customize*.  Now you
   should be on a normal DTML Method editing form.  If you look at the
   path, you'll notice you're now in 'portal_skins/custom/news_box'.
   This is where you can safely start to customize your own site,
   independant of whatever changes occur in the default stylings of
   the CMF.

   In another browser window, go to the front page of your CMF Site
   and verify that it says "No news is no news" in the news box
   (again, this won't occur if you actually have news items).  Then,
   back in the 'news_box' edit window, change the part of the source
   that says "No news is no news" to "There is nothing new under the
   sun".  Go back to your CMF front page and reload - it should now
   say the new phrase in the news box.

 Defining new skins

  Making new folders in the skins tool

  Customizing into the new folders

  Defining a new skin