Providing Portlets to Manage Requests

In this tutorial, you’ll learn how to declare an entity type and action for a desired function, and you’ll create a module that finds the correct application (portlet) to use based on those given parameters.

Specifying a Desired Portlet Behavior

To find the portlet you need for your particular request, you’ll use the Portlet Providers framework. The first thing you’ll need to do is call the PortletProviderUtil class and request the framework find a portlet suitable for the current task. You can request the portlet ID or portlet URL, depending on what you prefer. Here’s an example declaration:

String portletId = PortletProviderUtil.getPortletId(
    "com.liferay.portlet.trash.model.TrashEntry", PortletProvider.Action.VIEW);

This declaration expects two parameters: the class name of the entity type you want the portlet to handle and the type of action. The above code requests a portlet ID for a portlet that can view Recycle Bin entries.

There are five different kinds of actions supported by the Portlet Providers framework: ADD, BROWSE, EDIT, PREVIEW, and VIEW. Find the portlet ID or portlet URL (depending on your needs), and specify the entity type and action you want the portlet to handle.

Note: The getPortletURL methods require an additional HttpServletRequest or PortletRequest parameter, depending on which you use. Make sure to account for this additional parameter when using the getPortletURL method.

You’ve successfully requested the portlet ID/portlet URL of a portlet that matches your entity and action type. The portal, however, is not yet configured to handle this request. You’ll need to create a module that can find the correct portlet to handle the request.

1. Create an OSGi module.

2. Create a unique package name in the module’s src directory and create a new Java class in that package. To follow naming conventions, name the class based on the element type and action type, followed by PortletProvider (e.g., LanguageEntryViewPortletProvider). The class should extend the BasePortletProvider class and implement the appropriate portlet provider interface based on the action type you chose your portlet to handle (e.g., ViewPortletProvider, BrowsePortletProvider, etc.).

3. Directly above the class’s declaration, insert the following annotation:

    @Component(
        immediate = true,
        property = {"model.class.name=CLASS_NAME"},
        service = INTERFACE.class
    )
   

   The property element should match the element type you specified in your getPortletID/getPortletURL declaration (e.g., com.liferay.portal.kernel.servlet.taglib.ui.LanguageEntry). Also, your service element should match the interface you’re implementing (e.g., ViewPortletProvider.class). You can view an example of a similar @Component annotation in the RolesSelectorEditPortletProvider class:

    @Component(
        immediate = true,
        property = {"model.class.name=com.liferay.portal.kernel.model.UserGroupRole"},
        service = EditPortletProvider.class
    )
   

4. In some cases, a default portlet is already in place to handle the entity and action type requested. To override the default portlet with a custom portlet, you can assign your portlet a higher service ranking. You can do this by setting the following property in your @Component declaration:

    property= {"service.ranking:Integer=10"}
   

   Make sure to replace the integer with a number that is ranked higher than the portlet being used by default.

5. Specify the methods you’d like to implement. Make sure to retrieve the portlet ID/portlet URL that should be provided when this service is called.

Lastly, generate the module’s JAR file and deploy it to your portal instance. Now a portlet that can handle the entity and action type you specified is used when requesting a portlet ID/URL. You can now specify portlet usage without hardcoding a specific portlet!

Related Topics

Portlets

Embedding Portlets in Themes

Customizing Liferay Services