Product flavors are required by production level apps to provide different versions of their app available to people. Each of the flavor has separate functionality depending on the type of flavors chosen. Most common flavors are full and demo flavors, from their name only we can understand that these flavors contain full version and demo version of their apps. Since SUSI.AI android app has to be released on FDroid several libraries that were present in the current app were not  acceptable by them as it only allows apps that completely use only open source software to develop and therefore there was a need to make the app compatible with both the app stores (Play Store and FDroid) product flavors were added in the app.

Proprietary software in the app

There are several libraries which are not acceptable on FDroid but are present in the app, a couple of them being :

1. Crashlytics using fabric
2. LinkPreview library

These two libraries were found which are not acceptable in FDroid. Although the link preview library was not proprietary software, but fdroid has guidelines which only allows that recognised and trusted libraries from maven repository is accepted.

Further, youtube api recently integrated in the app is also not acceptable by FDroid as it is under google and categorised as a proprietary software.

Adding product flavors

The flavor names chosen to be made were “fdroid” and “playStore”, fdroid here specifying the build variant for the app that would contain the libraries and code acceptable by fdroid and playStore flavor to contain the sources and libraries for the regular version of the app which can contain proprietary software.

The flavors were added as shown below in the module level build.gradle file :

flavorDimensions “default” productFlavors {   fdroid {       dimension “default”       applicationIdSuffix “.fdroid”       versionNameSuffix “-FDroid”   }   playStore {       dimension “default”       versionNameSuffix “-PlayStore”   } }

the flavors are added under the block of code by the name productFlavors, and each flavor needs to have some properties to be set. The applicationId of the app can be changed or can be kept same, in our case for the fdroid flavor the applicationIdSuffix was added which adds “.fdroid” at the end of the applicationId for the fdroid version.

versionNameSuffix property was set in both the flavors which adds “-FDroid” to end of the versionname for the fdroid variant and “-PlayStore” to the end of the versionname for the playstore variant.

Using the product flavors we can generate multiple apks , as in our case after the build flavors were added there were four apks built. These can be seen as  :

Choosing any of these apks we can select the variant that is to be worked upon. The debug apks here are those used for developing purposes.

Conclusion

Adding flavors allows SUSI.AI android app to keep separate code and resources for different variants. Any code that is different to both the variants is added separately after creating the directories named “fdroid” and “playStore” in the src folder.

This was added after switching to the Project view in Android Studio and then moving to the app folder and then inside the src folder make a directories named fdroid and playStore.

References

1. Configure Build Variants: https://developer.android.com/studio/build/
2. Android Product Flavors: https://medium.com/@iammert/android-product-flavors-1ef276b2bbc1

Handling multiple java sources and flavors using flavors on Gradle: https://medium.com/@thiagolopessilva/the-handling-multiple-java-source-and-resources-using-flavors-on-gradle-18a4b581285b