Extend my android app in different APK

Question

I am developing an application that should be extendable I want the user to install the base app and then extend it by installing extension packs (different APKs) or plug-ins (

Answer 1

To build this type of interaction, ContentProvider will be your friend. There are two options I can think of to build this type of system, depending on which direction you would like information to flow.

Option 1: Single ContentProvider in main application

Define a ContentProvider in your main application, which creates an external interface for other applications to read/write data to a common location. This provider maintains access to the scene data files/database your application needs.

Each subsequent plugin application accesses the main ContentProvider (and also warns the user if they run a plugin but haven't installed the main app yet) and installs its specific content by writing it to the ContentProvider. In this way, each plugin is designed to act as an "installer", meaning the user has to download and run the plugin from Market to install the scene content.

Option 2: Each "Plugin" application has its own ContentProvider

This option is the reverse of the above. Define a ContentProvider with a consistent interface in each plugin application and have a method from the main application that scans the system for new plugins (this can be done via PackageManager) and reads the data from each provider into its main local store.

The difference here is that the user won't have to run each plugin package, because the main application will take care of getting the data. However, there's more complexity in defining multiple providers. For instance, you have to make sure that, even if each provider has the same basic interface, they cannot have a single common authority, so you will have to scan the system for package names like your own and resolve the providers based on that information.

Editorial

Having said that, I feel I should mention that I don't believe this is a good method of providing content to your users. My personal feeling on the subject is this method pollutes the user's devices with application icons that do them no good, and it's difficult to hide that kind of thing on the mobile device. A simpler, and much cleaner approach to this would be to store your "add-on" content on a server (AWS services like S3 and SimpleDB are practically free) and use a service like Google's In-App Billing to let your users purchase the new content and download it directly into the single application rather than having them go back to Market and purchase more apps.

Hope that Helps!