rh-id / a-provider

This is a simple pure java service locator for Android

a-provider

This is a simple Service Locator for Android projects that doesn't rely on annotations or "magic"

Example Usage

This project support jitpack, in order to use this, you need to add jitpack to your project root build.gradle:

allprojects {
    repositories {
        google()
        mavenCentral()
        maven { url "https://jitpack.io" }
        jcenter() // Warning: this repository is going to shut down soon
    }
}

Include this to your module dependency (module build.gradle)

dependencies {
    implementation 'com.github.rh-id:a-provider:v0.0.1'
}

Then you could proceed writing code, First create root module as a root of the provider to provide services.

public class RootModule implements ProviderModule{
    @Override
    void provides(ProviderRegistry providerRegistry, Provider provider){
        // Register your services/components here or other ProviderModule
        providerRegistry.register(IService.class, () -> new ServiceImpl());
        providerRegistry.registerModule(new ProviderModuleA());
        // You could use registerLazy to lazy-load your services
        providerRegistry.registerLazy(IServiceA.class, ServiceAImpl::new);
        // You could use registerAsync to initialize your services in background thread
        providerRegistry.registerAsync(IServiceB.class,
                                        () -> new ServiceBImpl(provider.get(IServiceA.class)));
        // use registerFactory to load new instances everytime Provider.get() is invoked
        providerRegistry.registerFactory(MyPojo.class, () -> {
            MyPojo myPojo = new MyPojo();
            myPojo.setAge(99);
            myPojo.setName("Foo");
            return myPojo;
        });
        // OR use registerPool to load new instances everytime Provider.get() is invoked.
        providerRegistry.registerPool(MyPojo.class, () -> {
            MyPojo myPojo = new MyPojo();
            myPojo.setAge(99);
            myPojo.setName("Foo");
            return myPojo;
        });
    }

    @Override
    void dispose(Provider provider){
        // do something when this module is going to be disposed
    }
}

Initialize on your application for global access (example only)

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        // store the instance in static value for global access
        Provider provider = Provider.createProvider(this, new RootModule());
        // example retrieve value
        IServiceA iServiceA = provider.get(IServiceA.class);
        MyPojo myPojo = provider.get(MyPojo.class);
    }
}

If you need to handle dispose event you could implement ProviderDisposable to your component/services

public class ServiceAImpl implements IServiceA, ProviderDisposable {
    @Override
    public void dispose(Context context){
    // anything to dispose, this will be called on Provide.dispose
    }
}

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        Provider provider = Provider.createProvider(this, new RootModule());
        IServiceA iServiceA = provider.get(IServiceA.class);
        provider.dispose(); // ServiceAImpl.dispose(Context) will be called
    }
}

Skipping same type

For integration testing purposes you could turn on skipSameType. This will make providerRegistry ignore duplicate type during registration

Example production RootModule:

public class RootModule implements ProviderModule{
    @Override
    void provides(ProviderRegistry providerRegistry, Provider provider){
        providerRegistry.register(IService.class, () -> new ServiceImpl());
    }
}

Example test RootModule to be used:

public class TestRootModule extends RootModule{
    @Override
    void provides(ProviderRegistry providerRegistry, Provider provider){
        // register IService.class with test instance
        providerRegistry.register(IService.class, () -> new TestServiceImpl());

        providerRegistry.setSkipSameType(true); // enable
        // since skip is true, the IService.class from parent will not be registered again
        super.provides(providerRegistry, provider); 
        providerRegistry.setSkipSameType(false); // disable skip after done
    }
}

The configuration providerRegistry.setSkipSameType(true); can be useful on some circumstances such as multiple android app flavors or configuration

Example Projects

• https://github.com/rh-id/a-news-provider
• https://github.com/rh-id/a-flash-deck
• https://github.com/rh-id/a-medic-log
• https://github.com/rh-id/a-personal-stuff

Support this project

Consider donation to support this project

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