The key to building virtual applications is the addition of post-processing functions or filters to the application’s portlets. Post-processing functions can either transform a portlet’s content (for example, render the content as a chart), or create events For example, you can transform a portlet’s content into a chart or you can create events that are triggered when a user accesses a portlet’s content. You can add more than one post-processing function to handle a portlet’s content and configure the order in which the postprocessing occurs. When you use multiple postprocessing functions, each function operates on the output of the previous function—similar to a Pipes and Filter design.
Pipes and Filters is a design architecture where the
components are known as filters and the connectors are the pipes.
Filters read input data, perform some computation or transformation
on the data, and produce output data. Pipes serve as conduits for
the data streams, passing outputs from one filter to the inputs
of another filter.
The post-processing options are available by right-clicking a portlet in the Application Builder left pane:
Define Events – launches an Event Definition wizard. See“Defining broadcast events” and “Adding events”.
Define Listeners – launches a Listener Definition wizard. See “Adding listeners”.
Create Chart – lets you chart a portlet’s structured content. See “Adding charts”.
Form Parser – lets you process form input and define which form parameters should be event default values or listeners for events from other sources. See “Adding form processing”.
Create JSP Filter – lets you write custom code to process portlet content. See “Adding a JSP filter”.
Text Processor – launches a text processor wizard that lets you define an event to occur when the user clicks on selected text. See “Processing text to trigger events”.
Order Post Processing – lets you sequence a portlet’s postprocessing options at anytime. See “Ordering filters”.
Invisible Status – lets you hide a specific portlet from the end user. See “Invisible status”.
All available post-processing modules are configured in the uwp.xml configuration file, which is located in %JAGUAR%\Repository\WebApplication\onepage\fw\properties on Windows and in $JAGUAR/Repository/WebApplication/onepage/fw/properties on UNIX.
To add additional post-processing modules, use this interface:
Public interface PortletProccessingFilter {
String Process(string content, UWPRequest resquest,
UWPResponse response, UWPDataAccess access);
}
The following five post-processing filters will be offered as a part of the current implementation.
<PostProcessingFilters>
<FilterDef name="Events" class="com.onepage.fw.uwp.filters.events"/>
<FilterDef name="Listeners" class="com.onepage.fw.uwp.filters.listeners"/>
<FilterDef name="Forms" class="com.onepage.fw.uwp.filters.forms"/>
<FilterDef name="Charts" class="com.onepage.fw.uwp.filters.charts"/>
<FilterDef name="jsp" class="com.onepage.fw.uwp.filters.jsp"/>
</PostProcessingFilters>
There is a method in the UWPManager getPostProcessingFilters that returns a list of configured filters.
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