Q:

How to update Android projects from a template?

Currently I am working on an application aimed to small local businesses, which serves as a template for other applications (other stores). The base application allows local stores to send notifications to their customers, depending on the business context, notifications can be to report promotions, inform a client that he can pick up his order at the store, notices of new products in the store, etc ... What I do is work on the template for each client and then customize the appearance of the application in the background but the functionality is the same for everyone. My problem is that every time we have more businesses interested in the application and the problem arises when I find bugs or want further improvements, and to update the code in each of the applications can be hell (open each project, add the lines code, recompile, etc ...), and also publish new applications involves a great job because I have to change namespaces whole project, change the authority of the content provider, update references to the namespace associated with the template, etc. ...
Is there any way that I provide update and / or add portions of code in the original template and the changes are automatically reflected in all projects generated from the template?
I have understood Apache Ant can help with the compiling process of  large project with many dependencies, but could be useful in the context of my problem?
The solution that I can think of right now is to create a project library and then put everything common to projects, including resources and Activities. The problem is that for example the application Content Provider could not go there because I need to have a single authority in the Manifiest defined for each application.
In advance thank you very much for taking the time to read my message. Any help or advice is welcome. Thank you again.

A:

My question is there any way that I provide update and / or add portions of code in the original template and the changes are automatically reflected in all projects generated from the template?

Make the core code be an Android library project, and use that library project in all the customer apps.

The solution that I can think of right now is to create a project library and then put everything common to projects, including resources and Activities.

Correct.

The problem is that for example the application Content Provider could not go there because I need to have a single authority in the Manifiest defined for each application.

Your ContentProvider implementation can go in the library project. Your customer-specific project will need the <provider> element in the manifest, with a unique authority, pointing to the ContentProvider class from the library.

