Updating the plugin.xml file for a VCT

After you have created your visualizer plug-in, you are ready to update its

plugin.xml file.

Creating a visualizer plug-in

To update the plugin.xml file for a visualizer plug-in:

1. Open the

   plugin.xml file for editing.

2. Just after the <runtime> tag, add the following tags. Note that the data and time example we are using refers to specific visual custom tags (VCT).

    <requires>
              <import plugin="com.ibm.etools.webedit.core"/>
    </requires>
   
    <extension point="com.ibm.etools.webedit.core.visualCustomTag">
       <vtaglib uri="/WEB-INF/lib/sample.jar">
          <vtag	name="date"
                class="com.ibm.etools.webedit.vct.sample.DateTimeTagVisualizer"
                description="Dynamically outputs current date and time"/>
       </vtaglib>
    </extension>

   In the above example, you used the <requires> and <import> elements to specify what other plug-ins the visualizer plug-in needed. Then, you imported the com.ibm.etools.webedit.core plug-in, and used the <extension> element to specify what this plug-in contributes. The plug-in connects to the extension point specified by the <extension> element's point attribute.

   The <vtaglib> element is similar to a <taglib> and specifies the VCTs that are available. The URI attribute of the <vtaglib> element serves as an identifier for the VCTs. When Page Designer discovers a custom tag, it looks for the taglib directive declaring the custom tag. It gets the URI attribute value of the taglib directive and tries to match it with the URI attribute of the <vtaglib> element. When a match is found, that plug-in is used to visualize the custom tag. Thus, the value of <vtaglib> element's URI attribute must be the same as the URI value specified in the taglib directive of the JSP page for the visualizers to work.

   The <vtag> element specifies the name of the VCT and the visualizer Java™ class. In the example, the tag is date and the visualizer that is executed is com.ibm.etools.webedit.vct.sample.DateTimeTagVisualizer. You can write some comments in the description attribute.

3. Before you create the JSP file, add additional plug-ins.

   1. Select

      Window | Preferences from the menu bar. The

      Preferences page appears.

   2. Select

      Plug-in Development | Target Platform from the list. Click

      Not In Workspace and then click OK.

4. Update the Java classpath to include the imported plug-in classes: org.apache.xerces and com.ibm.etools.webedit.core.

   1. Right-click the plug-in project in the Package Explorer. Select

      Update Classpath from the pop-up menu. The

      Java Classpath dialog box opens.

   2. Click Finish. The Java classpath of the plug-in project is updated to include the two plug-ins.

Now you are ready to use the visual custom tag in a JSP page.

 

Related concepts

Custom tag libraries

Visual custom tags (VCTs)

 

Related tasks

Creating visual custom tags (VCTs)

Creating a visualizer plug-in

Creating a visualization for a custom component tag

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