### Defining a custom IntroURL action

Using the org.eclipse.ui.intro.configExtension extension point, plug-ins can contribute their own custom actions that can be used as a url value for a link element in a page. For example, consider the following link:

`http://org.eclipse.ui.intro/runAction?pluginId=org.eclipse.pde.ui&class=org.eclipse.pde.ui.internal.samples.ShowSampleAction&id=org.eclipse.sdk.samples.swt.examples`

This IntroURL will run an action class called ShowSampleAction, which is in a package "org.eclipse.pde.ui.internal.samples" in the plug-in "org.eclipse.pde.ui". The id of the sample to run is "org.eclipse.sdk.samples.swt.examples".

To define a custom version of this intro URL, you can use the following markup:

    <extension point="org.eclipse.ui.intro.configExtension">
    	<action
    		name="myCommand"
    		replaces="runAction?pluginId=org.eclipse.pde.ui&class=org.eclipse.pde.ui.internal.samples.ShowSampleAction">
    	</action>
    </extension>

With the above extension you can now use the following URL to run the same action:

`http://org.eclipse.ui.intro/myCommand?id=org.eclipse.sdk.samples.swt.examples`

The action "myCommand" will be replaced by the value of the replaces attribute and any remaining URL parameters will be appended to the end. Once the substitution is made, the resulting URL will be expanded back into:

`http://org.eclipse.ui.intro/runAction?pluginId=org.eclipse.pde.ui&class=org.eclipse.pde.ui.internal.samples.ShowSampleAction&id=org.eclipse.sdk.samples.swt.examples`