<skin>
<javascript>path/to/javascript1.js</javascript>
<css>path/to/stylesheet.css</css>
</skin>

This skin has 1 javascript file and 1 stylesheet. Note that the paths do not start with "/" characters; this denotes these files are relative to the web context (e.g. /uPortal/path/to/javascript.js).

<skin>
<css>path/to/stylesheet.css</css>
<css conditional="if IE gt 6>path/to/ie6-hack.css</css>
</skin>

0 javascript files, 2 stylesheets. The 2nd stylesheet is included in an Internet Explorer conditional comment.

<?xml version="1.0" encoding="UTF-8"?>
<resources>
  <!-- base Fluid Skinning System -->
  <css>../common/css/fluid/fluid.reset.css</css>
  <css>../common/css/fluid/fluid.layout.css</css>
  <css>../common/css/fluid/fluid.text.css</css>
  
  <!-- For printing of portal pages. Common to all skins using the universality theme -->
  <css>../common/css/print.css</css>
  
  <!-- For layout of portal pages (in tandem with FSS fluid.layout.css). Common to all skins using the universality theme. -->
  <css>../common/css/layout.css</css>
  
  <!-- Support for legacy uPortal css classes. -->
  <css>uportal3_legacy.css</css>
  
  <!-- Default jqueryui css -->
  <css>/ResourceServingWebapp/rs/jqueryui/1.6rc6/theme/smoothness/ui.all.css</css>
  
  <!-- uPortal jqueryui override css -->
  <css>jquery.css</css>
  
  <!-- Visual style for the portal. Built and formatted as a Fluid Skinning System theme. -->
  <css>fluid.theme.uportal3.css</css>
  
  <!-- Visual style for portlet content. An extension of the uportal3 skin. -->
  <css>uportal3_portlet.css</css>
  <css>jsr168_portlet_spec.css</css>
  
  <!-- Overrides specific to IE6. -->
  <css conditional="if IE 6">uportal3_ie6override.css</css>
  
  <js>../common/javascript/uportal/ajax-preferences-jquery.js</js>
  <js>../common/javascript/uportal/up-channel-browser.js</js>
  <js>../common/javascript/uportal/up-group-browser.js</js>
  <js>../common/javascript/uportal/flyout-nav.js</js>
</resources>

Directory structure for the corresponding skin and shared files:

uportal-war/src/main/webapp/media/skins/universality
|-- common
|   |-- css
|   |   |-- fluid
|   |   |   |-- fluid.layout.css
|   |   |   |-- fluid.reset.css
|   |   |   `-- fluid.text.css
|   |   |-- layout.css
|   |   `-- print.css
|   `-- javascript
|       `-- uportal
|           |-- ajax-preferences-jquery.js
|           |-- flyout-nav.js
|           |-- up-channel-browser.js
|           `-- up-group-browser.js
|-- skinList.xml
|-- universality_full.gif
|-- universality_icon.gif
`-- uportal3
    |-- fluid.theme.uportal3.css
    |-- jquery.css
    |-- jsr168_portlet_spec.css
    |-- skin.xml
    |-- uportal3_ie6override.css
    |-- uportal3_legacy.css
    `-- uportal3_portlet.css

After running through the plugin the following skin.aggr.xml would exist:

<?xml version="1.0" encoding="UTF-8"?>
<resources>
  <!--
    | AGGREGATE OF:
    |  ../common/css/fluid/fluid.reset.css
    |  ../common/css/fluid/fluid.layout.css
    |  ../common/css/fluid/fluid.text.css
    +-->
  <css>../common/css/fluid/uportal3_aggr1_MD5GOESHERE.css</css>
  
  <!--
    | AGGREGATE OF:
    |  ../common/css/print.css
    |  ../common/css/layout.css
    +-->
  <css>../common/css/uportal3_aggr2_MD5GOESHERE.css</css>
  
  <!--
    | AGGREGATE OF:
    |  uportal3_legacy.css
    +-->
  <css>uportal3_aggr3_MD5GOESHERE.css</css>
  
  <!--
    | AGGREGATION BREAK:
    |  external resource, causes break in aggregation to maintain ordering
    +-->
  <css>/ResourceServingWebapp/rs/jqueryui/1.6rc6/theme/smoothness/ui.all.css</css>
  
  <!--
    | AGGREGATE OF:
    |  jquery.css
    |  fluid.theme.uportal3.css
    |  uportal3_portlet.css
    |  jsr168_portlet_spec.css
    +-->
  <css>../common/css/uportal3_aggr4_MD5GOESHERE.css</css>
  
  <!--
    | AGGREGATE OF: (break in aggregation due to change in conditional from previous <css> element)
    |  uportal3_ie6override.css
    +-->
  <css conditional="if IE 6">uportal3_aggr5_MD5GOESHERE.css</css>
  
  <!--
    | AGGREGATE OF:
    |  ../common/javascript/uportal/ajax-preferences-jquery.js
    |  ../common/javascript/uportal/up-channel-browser.js
    |  ../common/javascript/uportal/up-group-browser.js
    |  ../common/javascript/uportal/flyout-nav.js
    +-->
  <js>../common/javascript/uportal/uportal3_aggr1_MD5GOESHERE.js</js>
</resources>

Where skin is the name of the skin the resource definition XML file is for, aggrN is an incrementing value to make tracking aggregate order easier, MD5 is the MD5 hash of the file's contents and type is the file type css or js.

• XSD for XML representation of skin configuration
• JAXB annotated classes for marshalling/unmarshalling skin configuration to/from Java data model
• IResourcesAggregator interface and implementation; automatically aggregates Css and Js objects that are "aggregatable" (same parent path, conditional, and media values), optionally compressing using YUI compressor.
• tests cases on sample skins

Outstanding work yet:

• Resolve some problems using the JavaScriptCompressor in YUI Compressor package; I think it's very strict out of the box and fails to compress javascript if there are minor problems in the source
• Test cases for the Mojo, incorporate with uportal3 build, verify works with universality skin
• Integrate aggregated output with XSL transformation so the aggregated versions of the files are included in the head (toggled via runtime with System property)

Mojo has been tested successfully as part of the uPortal build.

Committed a copy of the resources/js/css object model in uPortal/trunk, along with a Xalan extension implementation that can convert the resources into the appropriate script and link HTML tags.

Outstanding work:

• The requirements for this task locate the resources skin.xml file along with the css and javascript files, under uPortal/uportal-war/src/main/webapp/media. This location is not on the classpath, which will make it difficult to locate. Will need to come up with a way to either locate the skin.xml file on the classpath, or be able to resolve it's location from the theme xsl (which is on the classpath).
• Update the StaticRenderingPipeline to set the configured Resources as a transformer parameter (which will result in the Xalan extension mentioned above rendering the script/link tags in the head)

Almost done!

I have an update to the StaticRenderingPipeline and universality's page.xsl that does in fact accomplish the goals of this task (it works!), however I have to hold off on checking it in until we:

1. resolve the YUI Compressor issue mentioned in the prior comment
2. release a version of the maven-uportal-plugin - I have an update to uportal-war/pom.xml that depends on that plugin, which isn't available via maven (I have it installed in my local repository)

Checking these last 2 modifications in before resolving the above would temporarily break trunk.

uPortal trunk now has working implementation, depends on release 1.0.0-M2 of maven-uportal-plugin to aggregate during uportal-war build.