ScottPierce/kinject

A simple Kotlin Multiplatform dependency injection library.

Kinject

This library was made from a series of blog posts on creating a Kotlin Dependency Injection Library. You can find all the posts here.

A multiplatform Dependency Injection library.

Artifacts

implementation("dev.scottpierce:kinject-core:<latest version here>")

Artifact	Description
kinject-core	Provides core DI functionality.
kinject-android	Provides helper methods for working with ObjectGraphs embedded in Contexts, and helper classes for embedding ObjectGraphs in Contexts.
kinject-android-appcompat	Provides KinjectAppCompatActivity.
kinject-android-compose	Provides KinjectComponentActivity.
kinject-compose	Provides the ability to provide an ObjectGraph in a Compose hierarchy.
kinject-compose-viewmodel	Provides the ability to get a ViewModel in a compose hierarchy.
kinject-compose-voyager	Provides the ability to get a ScreenModel in a compose hierarchy.
kinject-coroutines	Provides a KinjectCoroutineContextElement, to easily allow passing an ObjectGraph via a CoroutineContext.
kinject-viewmodel	Provides the ability to declare a view model dependency, and a factory to create it.

Basic Usage

Dependencies:

class A

class B(val a: A)

class C(
    val a: A,
    val b: B,
)

Usage:

val graph = objectGraph {
    singleton(A())                          // Provided Binding
    singleton { B(a = get()) }              // Lazy Binding
    singleton { C(a = get(), b = get()) }   // Lazy Binding
}

val a: A = graph.get()
val b: B = graph.get()
val c: C = graph.get()

Adding an ObjectGraph to another ObjectGraph

ObjectGraphs can be added together to scope dependencies. After adding a graph, all of it's dependencies become accessible to the new graph.

val graph1 = objectGraph {
    singleton(A())
    singleton { B(a = get()) }
}

val graph2 = objectGraph {
    add(graph1)                             // Add the first graph 2 this graph
    
    singleton { C(a = get(), b = get()) }   // Now we can access all of the first graphs dependencies
}

val a: A = graph2.get()
val b: B = graph2.get()
val c: C = graph2.get()