Weblets

Subbundles

As of Weblets 1.2 the possibility of subbundles has been added to the weblets core. Subbundles are simply bundles within bundles which enable certain functionality.

Lets take a look at the subbundles from the problem point of view.

An average page request has several includes for instance an include to three javascript files several css files.

Under normal circumstances you have one request per include, even if the request is served out of the cache, which happens in 20-40% of all request that means a significant slowdown because every request has to be processed separately by the browser.

Additionally to that if no cache is active or we have an empty cache hit, the server has to endure a series of requests per page request to serve the needed resources! Under normal circumstances it makes sense to bundle several resources which can be grouped together, to reduce both browser processing time and server load!

Now to resolve this issue we have two tools.

• Our indirection API
The subbundles

General Mechanism

<weblet>
    <weblet-name>weblets.demo</weblet-name>
    <weblet-class>
        net.java.dev.weblets.packaged.PackagedWeblet
    </weblet-class>
    <weblet-version>1.0</weblet-version>

    <subbundle>
        <id>scripts/bundlescript1.js</id>
        <resources>
            /scripts/script1.js,
            /scripts/script2.js,
            /scripts/script3.js
        </resources>
    </subbundle>


    <subbundle>
        <id>scripts/cssbundle1.css</id>
        <resources>
            css/css1.css, css/css2.css, css/css3.css
        </resources>
    </subbundle>
</weblet>
        

In this example two bundles are defined, both bundles are concatenated at indirection access to the resource name defined in the <id\> field!

Now what happens at access time? The indirection api resolves the first request into the bundle to the resource defined in <id\> and ever other resource into empty strings, thus omitting the additional requests.

All resources in the bundle are concatenated on the fly and served as a single resources.

Now what happens if those resources are accessed directly?

• The first access sends the entire bundle!
• all other accesses send empty strings.

To cope with this an API has been added which allows to check for already included resources!

WebletUtils.isResourceLoaded(Servlet/Portletrequest request,  String weblet, String pathInfo)
        

public static boolean FacesWebletUtils.isResourceLoaded(FacesContext context, String weblet, String pathInfo)
        

#{isResourceLoaded(weblet, pathInfo)}