Building the Guestbook Mobile SDK

Once you’ve deployed the Guestbook portlet, you’re ready to build the Guestbook Mobile SDK. You might be asking yourself, “Why do I have to build a separate Mobile SDK? Can’t I just use the pre-built Mobile SDK that Liferay already provides?” Fantastic question! The reason is that Liferay’s pre-built Mobile SDK doesn’t have the classes it needs to call the Guestbook portlet’s remote services. The pre-built Mobile SDK includes only the framework necessary to make server calls to the remote services of Liferay DXP’s core apps. Core apps (also referred to as out-of-the-box apps) are those included with every Liferay DXP instance. Since you’re calling services of an app the default Mobile SDK doesn’t know about (the Guestbook portlet), you must build a Mobile SDK that can call its services. Now put on your hard hat, because it’s time to get building!

Building the Mobile SDK

In the Mobile SDK source code, Liferay provides a Mobile SDK Builder that you can use to build your own Mobile SDKs. For the builder to generate the classes that can call a non-core app’s remote services, those services must be available and accompanied by a Web Service Deployment Descriptor (WSDD). To learn how the Guestbook portlet’s remote services and WSDD were generated, see the section Generating Web Services in the web application Learning Path. Since the Guestbook portlet’s web services already exist, you don’t need to generate them. Just remember that you must generate web services when developing your own portlets.

To build the Guestbook Mobile SDK, first download the Mobile SDK’s source code by clicking here. Unzip the file to a location on your machine where you want the Mobile SDK to reside. This location is purely personal preference; the builder works the same no matter where you put the Mobile SDK’s source code. Once unzipped, the Mobile SDK’s source code is in the liferay-mobile-sdk-android-7.0.6 folder.

Now you’re ready to build the Guestbook Mobile SDK. The builder contains a convenient command line wizard to assist you in building Mobile SDKs. To start it, navigate to the liferay-mobile-sdk-android-7.0.6 folder and run the following command:

./gradlew createModule

The wizard launches and asks you to enter your project’s properties. You must first provide the Context property. This is the context path of the remote services the builder will generate classes and methods for. To view your Liferay DXP instance’s remote service context paths, go to http://localhost:8080/api/jsonws. On the page’s upper left, there’s a menu for selecting the context path. Select gb, which is the Guestbook portlet’s context path. The UI updates to show only the remote services available in the selected context path. Return to the terminal and enter gb for the Context property.

Figure 1: The Guestbook Portlet's context path (gb) on the server.

Next, the wizard needs the Package Name property. This is the package path for the classes the builder generates. Accept the default value of com.liferay.mobile.android. The wizard then asks for the POM Description property. Technically, you only need this if you want to publish your Mobile SDK to Maven. Since the builder requires it, however, enter Guestbook SDK. The following screenshot shows these properties entered in the wizard:

Figure 2: To build your Mobile SDK, you must enter values for the `Context`, `Package Name`, and `POM Description` properties. The blue values in square brackets are defaults.

Once you enter the final property, the builder runs and generates a BUILD SUCCESSFUL message. Now that the builder contains a gb module, you must generate that module’s remote services. To do this, first navigate to the following folder:

liferay-mobile-sdk-android-7.0.6/modules/gb

Then run the following command:

../../gradlew generate

As before, the builder runs and generates a BUILD SUCCESSFUL message. Great! You’re probably wondering what just happened, though. The builder generated the source classes you’ll use in your Android app to interact with the Guestbook portlet. You can find these source classes in the following folder of the Mobile SDK’s source code:

modules/gb/android/src/gen/java

Also note that the source classes are in the package path you specified when generating the module, with an additional folder that denotes the Liferay DXP version they work with. The full path to the generated source classes is therefore:

modules/gb/android/src/gen/java/com/liferay/mobile/android/v7

This folder has two subfolders that correspond to each entity in the Guestbook portlet: guestbook and entry. Each subfolder contains that entity’s source class, GuestbookService and EntryService, respectively.

There’s one last thing to do before you can use these classes in your Android app: put them in a JAR file. To do this, make sure you’re still in the modules/gb folder on the command line and run ../../gradlew jar. This command does two things:

1. Generates a JAR file in modules/gb/build/libs that contains the Guestbook portlet’s service classes. This JAR file is the Guestbook Mobile SDK.

2. Generates a custom-built version of Liferay’s pre-built Mobile SDK in liferay-mobile-sdk-android-7.0.6/android/build/libs.

Congratulations! You just built the Guestbook Mobile SDK. Now that’s an accomplishment worth writing in a guestbook. All you need now is an Android app in which to install this Mobile SDK. The next article shows you how to create this.