How to include 3rd party aar into Android React Native module?

Question

I am building an android React Native module and my code imports classes from a 3rd party SDK which is provided as an aar file. How should I bundle this file into my module? I tried adding

allprojects {
    repositories {
        flatDir {
            dirs: 'libs'
        }
    }
}

and

dependencies {
    ... other deps ...
    compile (name:'my-external-lib', ext:'aar')
}

to the build.gradle file and putting this my-external-lib.aar file into libs/ folder, but still getting an error when building MyApp react-native application with react-native-my-module included:

* What went wrong:
A problem occurred configuring project ':app'.
> Could not resolve all dependencies for configuration 
':app:_developmentDebugApkCopy'.
   > Could not find :my-external-lib:.
     Required by:
         MyApp:app:unspecified > MyApp:react-native-my-module:unspecified

Any advice?

Answer 1

Looks like I managed to solve this question by myself. It seems that you need to define repositories in the main project to allow sub-projects locate their dependencies.

Putting this to the main project build.gradle file:

repositories {
    flatDir {
        dirs: 'libs'
    }
}

did the trick.

I believe though, that this is not the correct way to include sub-projects with dependencies, because you're obviously can't know how to amend your build.gradle file if this library is a 3rd party lib from npm. So, can someone explain why this worked and how should it be done in the right way?