Tip: Configuring Blojsom for Tagging and a del.icio.us-like Tag Cloud

I am looking for a blog server for my present research in the application of blogs and digital libraries in knowledge management. Blojsom and Pebble, two Java blog servers for hosting under Tomcat 5, seem interesting to me.

Blojsom is a well-established product and is the technology that underlies Apple Mac OS X Server Collaboration Services. It comes with a wide variety of plug-ins (which imply its extensibility) and is also accompanied by a good-looking javadoc.

Pebble, on the other hand, impressed me with its fancy support for del.icio.us-like tagging–see the developer's own blog here for example. But after spending some time looking at its documentation and mailing list on SourceForge, despite the developer's enthusiasm to support the community of users, I found Pebble less friendly to 3rd-party developers than Blojsom and anticipated troubles–with me and the developer–adapting it to my research work.

Therefore...I think I would rather go with Blojsom.

I spent some time googling this afternoon and came across a series of webpages that refer to tags and tag cloud in Blojsom. Kelmon's "Weblog as an Enterprise Project Management Communication Tool" project for his master degree in Information Technology from University of Liverpool, was the most useful to me. In his Plojsom software, he proposed a customized version of Blojsom that would be useful for enterprise project management.

Blojsom's Tagging and Tag Cloud plug-in modules were part of the proposed work.

Following Kelmon and the Blojsom "Available Plugins" Wiki, here is a procedure to enable tagging and tag cloud in Blojsom:

References:

Blojsom Wiki: Technorati Tags Plugin
Blojsom Wiki: Tag Cloud Plugin

Background:

1. The Tag Cloud plug-in generates a cloud of Technorati tags from blog entries.

2. The Technorati Tags plug-in by default generates and embeds the

<a href="http://www.technorati.com/tag/some-tag" rel="tag">

link. However, the blojsom wiki suggested that this template may be overridden from the default

<a href="http://www.technorati.com/tag/{0}" rel="tag">{0}</a>

to an arbitrary one by placing a file "technorati-tag-link.vm" in the subdirectory

"org/blojsom/plugin/technorati/templates/"

of a user's blog templates directory.

3. For information, the template command "#TechnoratiTags($entry)" in the file "asual-entry.vm" is used to generate the set of Technorati tags for a blog entry.

Procedure:

1. Edit the file

{user_name}/templates/asual-column.vm

and add the template below to generate the tag cloud.

#if (!$BLOJSOM_PERMALINK && $BLOJSOM_PLUGIN_TAG_CLOUD_MAP)
<div>
<h5>Tags:</h5>
#foreach($tag in $BLOJSOM_PLUGIN_TAG_CLOUD_MAP.keySet())
<span class="tagcloud$BLOJSOM_PLUGIN_TAG_CLOUD_MAP.get($tag)">
<a href="#BlogURL()?tq=$tag">$tag</a>
</span>
#end
</div>
#end

2. Create a file

{user_name}/templates/org/blojsom/plugin/technorati/templates/
technorati-tag-link.vm

with the content

<a href="http://localhost:8080/blojsom/blog/default/?tq={0}" rel="tag">{0}</a>

There should be no spaces or line breaks in the file.

3. Reload a blog page to verify the changes.

Keywords: blojsom, blogging, tagging, customization

Update: Aug 30, 2006:

I just learned about the "general (global) settings" concept of Blojsom. We can make most global changes in the "WEB-INF/bootstrap" directory in stead of the {user_name} folder. However, I guess global settings will be overridden by the specific ones in the {user_name} directory.