MidCOM 2.5, metadata and "the main object"

Greetings!

The latest wisdom for making well-performing MidCOM components is to  
populate NAP leaves from only the items that you absolutely want to  
make available to the site navigation. This means some things like  
changing between views of a component ("account details", "change  
password"), or navigation in simple content-oriented components like  
taviewer.

Since the rest of the components (including components like  
newsticker and photos) will not be using NAP for their contents, they  
must make MidCOM aware of what URL contains what content in other ways:

* Component interface class should resolve permalinks to views by  
implementing the _on_resolve_permalink() method

* Page titles should be registered using the $_MIDCOM->set_pagetitle 
() method

* Toolbars can be registered into the midcom_helper_toolbars static  
toolbar list (there are two toolbars relevant to components: "top"  
and "bottom" that practically replace the old NAP toolbar for  
switching between states)

However, this leaves one important aspect out of question: metadata.  
Since there is no active leaf selected, MidCOM's metadata system will  
not be able to provide information like "last updated" and "page  
author" into metatags.

I would propose to add another method to $_MIDCOM for registering the  
"main object" of a view as the object where metadata should be  
derived from. Something like:

$_MIDCOM->set_metadata_object($article);

This method should be called in component's handle phase, and the  
MidCOM metadata system should then utilize the $_MIDCOM->add_meta_head 
() method to populate appropriate information to all regular pages.

The information should by default at least include:
- Title of the main object as "dc.title"
- User who created the main object as "author" and "dc.creator"
- Initial creation date of the main object as "dc.date"
- Latest editing date of the main object as "lastupdated"
- Metadata keywords and summary of the object (if provided)
- PermaLink URL to the page as a "rel bookmark" link

In addition, it would be nice to display some information about the  
software setup. Something like:
- Component handling the main view (name and version) as  
"midcom.component"
- Generator of the page (Midgard, MidCOM and PHP versions) as  
"generator"

At the moment midcom-template handles this metadata population, and  
displays something like the following:

<link rel="bookmark" href="http://bergie.iki.fi/midcom- 
permalink-1c8e36dd7a43d34868de8d04ce5b5bd4" />
<meta name="generator" content="Midgard/1.6.3/Repository MidCOM/2.4.6  
PHP/4.3.10-15" />
<meta name="midcom.component" content="de.linkm.newsticker" />
<meta name="midcom.application" content="midcom-template/2005.07.27" />
<meta name="dc.date" content="2005-08-29" />
<meta name="dc.creator" content="Henri Bergius" />
<meta name="author" content="Henri Bergius" />
<meta name="dc.title" content="Posting pictures from iPhoto to  
Midgard" />
<meta name="lastupdated" content="2005-08-29" />

As m-t is going away soon, we must have a proper measure to replace  
it. Good meta tags are important for search engine ranking and  
machine-readability of the page.

/Bergie

Henri Bergius
Consultant Partner, Nemein
henri.bergius-ZpG/[email protected]

Midgard CMS
www.midgard-project.org