Linker

Linker provides an annotation-based API to handle URI routing for Android. This library is written in kotlin, and the generated codes are also pure kotlin.

Dependencies

Add the following to your build.gradle file:

dependencies {
	api 'me.twocities:linker:0.0.5'
	kapt 'me.twocities:linker-compiler:0.0.5'
}

Usage

There are two parts of Linker: annotations and LinkResolver

Annotations

@Link for activity

Use annotation @Link indicate which URI was respect:

@Link("link://product/detail{id})
class ProductActivity: AppCompatActivity {
}

@LinkPath @LinkQuery for parameters

@Link("link://product/detail/{id})
class ProductActivity: AppCompatActivity {
  @LinkPath("id") lateinit var productId: String
  @LinkQuery("title") lateinit var productTitle: String
}

After annotation processing, an extension function bindLinkParams() of ProductActivity will be generated, you can use it to get values of @LinkPath @LinkQuery params:

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
  bindLinkParams()
}

@LinkModule for module

// generate LinkerExampleLinkModule
@LinkModule
class ExampleLinkModule

After annotation processing, a module class was generated, will contains informations of all defined @Link, @LinkPath, @LinkQuery. The generated class will be used to decided which uri will be routed.

@LinkModule supports multi android's library module.

@LinkResolverBuilder for builder

// generate LinkerExampleLinkResolverBuilder
@LinkResolverBuilder(modules = arrayOf(ExampleLinkModule::class, LibraryLinkModule::class))
interface ExampleLinkResolverBuilder

This will generate a LinkResolver's builder:

val resolver = LinkerExampleLinkResolverBuilder(context).build()

LinkResolver

The definition of LinkResolver is much simpler:

interface LinkResolver {
  fun resolve(link: String): Result
}

Function resolve will parse the given link, and then return a Result, which has a nullable property of Intent, it will be null if no responding activities was found,

Routing:

val result = resolver.resolve("link//product/detail/123")
if (result.success()) startActivity(result.intent)

Thanks to kotlin, we can simplify this by writing extension function like this:

startActivity("link://product/detail/123")

see ObjectGraph for more details.

Advance

Linker also provide other mechanisms: Interceptor, FallbackHandler, which you can change the behavior of a link. You can add interceptors or set fallback handler by the generated builder class:

 val resolver = LinkerBuilder(context)
        .addInterceptor(HttpUrlInterceptor(context))
        .setFallbackHandler(DefaultUrlHandler(context))
        .setListener(ResolverListener())
        .build()

the Listener will be notified when an link was resolved.

Interceptors

The interceptor will give you an ability to change a link's intent, or put extra values to activity

// An interceptor handles how http(s) url was resolved
class HttpUrlInterceptor(private val context: Context) : Interceptor {
  override fun intercept(link: String, metadata: LinkMetadata?): Intent? {
    if (link.startsWith("http") or link.startsWith("https")) {
      // since `LINK` will be passed to intent automatically, we can return the intent directly
      return Intent(context, SimpleBrowserActivity::class.java)
    }
    return null
  }
}

FallbackHandler

If there's no activities match with the given link, or no interceptors has intercepted, the fallback handler be called. The [FallbackHandler] gives you the ability to handle unknown link: start another activity or show an error page.

TODO

• Generate link's builder when compiling
• Support multi links for per activity
• More unit tests

Credit

• DeepLinkDispatch
• ButterKnife

License

Apache License, Version 2.0