android - How to manage different support library versions for 3rd party deps with gradle?

Question

I have a bunch of third party libs that I include in my base application. I cannot control the support library those 3rd party modules include. This makes it hard to have the same version of the android support library in my application.

I know using gradle when I can exclude certain libraries from each dependency:

compile('com.test:lib1:1.0.0') {
    exclude group: 'com.android.support'
}

However there are a ton of support libraries and excluding them all for each one of my 3rd party libraries seems like overkill.

Is there a better way?

Reading this blog post: https://www.devsbedevin.net/android-understanding-gradle-dependencies-and-resolving-conflicts/

It suggests:

configurations.all {
  resolutionStrategy {
    preferProjectModules()
  }
}

However when using that I still get a warning in Android Studio in my gradle file that there are multiple versions of the support library detected.

What do I do if my dependencies depend on different versions of the support library? In either case above I would be forcing the 3rd party libraries to use a specific version of the support library that they were not build with. Which version am I supposed to use? Latest support library? Min support library of all 3rd party dependencies?

Here is a minimal gradle file example showing pulling in 3rd party dependencies that each depend on their own version of the support library.

android {
    compileSdkVersion 26
    buildToolsVersion '26.0.2'

    defaultConfig {
        applicationId "com.example.app"
        minSdkVersion 17
        targetSdkVersion 25
    }
}

configurations.all {
    resolutionStrategy {
        preferProjectModules()
    }
}

dependencies {
    compile 'com.android.support:support-v13:26.0.0'
    compile 'com.test:lib1:1.0' // depends on support-v13:25.0.0
    compile 'com.test:lib2:1.0' // depends on support-v13:25.2.0
    compile 'com.test:lib3:1.0' // depends on support-v13:25.4.0
    compile 'com.test:lib4:1.0' // depends on support-v13:26.0.0
}

Android studio gives the following warning:

Answer 1

This is certainly possible. In your projects build.gradle file (the top level build.gradle file) add the following code block:

ext {
    supportlib_version = '26.1.0'
    gps_version = '11.2.0'
}

//Ensure that all dependencies use the same version of the Android Support library
subprojects {
    project.configurations.all {
        resolutionStrategy.eachDependency { details ->
            if (details.requested.group == 'com.android.support'
                    && !details.requested.name.contains('multidex')) {
                details.useVersion "$supportlib_version"
            }
            if (details.requested.group == 'com.google.android.gms'
                    && !details.requested.name.contains('multidex')) {
                details.useVersion "$gps_version"
            }
        }
    }
}

The following code ensures that the 'com.android.support' dependency version will be equal to $supportlib_version for all dependencies. The same for the 'com.google.android.gms' framework.

Make sure that in your module's build.gradle file you also use these versions for your dependencies. E.g.:

compile "com.android.support:support-v4:$supportlib_version"

Read more about forcing a certain dependency version in the Official Gradle documentation.

Update Google has decoupled library versions. Therefore, forcing a specific version above 15.0.0 may not work. Instead, you can allow a limited range of versions. The example below allows any version higher than 15.0.0 but lower than 16.

gps_version = '[15.0.0, 16.0.0)'