Gradle : how to use BuildConfig in an android-libr

Question

My (gradle 1.10 and gradle plugin 0.8)-based android project consists of a big android-library that is a dependency for 3 different android-apps

In my library, I would love to be able to use a structure like this

if (BuildConfig.SOME_FLAG) {
    callToBigLibraries()
}

as proguard would be able to reduce the size of the produced apk, based on the final value of SOME_FLAG

But I can't figure how to do it with gradle as :

* the BuildConfig produced by the library doesn't have the same package name than the app
* I have to import the BuildConfig with the library package in the library
* The apk of an apps includes the BuildConfig with the package of the app but not the one with the package of the library.

I tried without success to play with BuildTypes and stuff like

release {
    // packageNameSuffix "library"
    buildConfigField "boolean", "SOME_FLAG", "true"
}
debug {
    //packageNameSuffix "library"
    buildConfigField "boolean", "SOME_FLAG", "true"
}

What is the right way to builds a shared BuildConfig for my library and my apps whose flags will be overridden at build in the apps?

Answer 1

use both

my build.gradle
// ...
productFlavors {
    internal {
        // applicationId "com.elevensein.sein.internal"
        applicationIdSuffix ".internal"
        resValue "string", "build_config_package", "com.elevensein.sein"
    }

    production {
        applicationId "com.elevensein.sein"
    }
}

I want to call like below

Boolean isDebug = (Boolean) BuildConfigUtils.getBuildConfigValue(context, "DEBUG");

BuildConfigUtils.java

public class BuildConfigUtils
{

    public static Object getBuildConfigValue (Context context, String fieldName)
    {
        Class<?> buildConfigClass = resolveBuildConfigClass(context);
        return getStaticFieldValue(buildConfigClass, fieldName);
    }

    public static Class<?> resolveBuildConfigClass (Context context)
    {
        int resId = context.getResources().getIdentifier("build_config_package",
                                                         "string",
                                                         context.getPackageName());
        if (resId != 0)
        {
            // defined in build.gradle
            return loadClass(context.getString(resId) + ".BuildConfig");
        }

        // not defined in build.gradle
        // try packageName + ".BuildConfig"
        return loadClass(context.getPackageName() + ".BuildConfig");

    }

    private static Class<?> loadClass (String className)
    {
        Log.i("BuildConfigUtils", "try class load : " + className);
        try { 
            return Class.forName(className); 
        } catch (ClassNotFoundException e) { 
            e.printStackTrace(); 
        }

        return null;
    }

    private static Object getStaticFieldValue (Class<?> clazz, String fieldName)
    {
        try { return clazz.getField(fieldName).get(null); }
        catch (NoSuchFieldException e) { e.printStackTrace(); }
        catch (IllegalAccessException e) { e.printStackTrace(); }
        return null;
    }
}