Question

Let’s say I have an app which does something (exactly what is irrelevant, as this is a very generic question), and I want other third-party developers to be able to expand the functionality of my application through an add-on like system. Just to give you an example of what I mean, I might develop an SMS app for which someone else could add support for Facebook chat, AIM etc. Is this possible, and if so, how would you go about doing this?

Answer 1

I’m pretty sure this isn’t allowed due to it would allow a 3rd party to circumvent the permission system in Android. If could get an App to load code not shipped with it then they could get elevated permissions without the user knowing. Even if you had to request permissions when installing the 3rd party plugin those permissions don’t have to include the permissions of the App you are augmenting. Therefore, if that code got loaded into the same process as the App it would be allowed to execute at the level of permissions the orignal App had instead of the ones it presented to the user.

Therefore, your only option is to leverage intents, but intents don’t have to invoke Activites. You could build a service, or broadcast method to do some processing and give back the results to the original activity. Read up on them and see if you can leverage them. Android’s system is a system of collaborating applications not plugins.

http://developer.android.com/guide/topics/intents/intents-filters.html