KODI
KOtlin Dependency Injection (KODI)
This is simple and useful dependency injection framework for work with your regular projects. It use standart Kotlin language construction like literal function with recieve
, infix function
, hight-order function
, ets. to bind and inject dependencies into your objects. It has two packages:
- Kodi library
It's a dependency injection library writen in pure Kotlin. This library has intuitive sintax like:
bind<SomeClassInterface>() at "Any_String_Scope_Name" with singleton { SomeClassImplementation() }
No annotation processing, and reflection in core module.
You can bind
three type of instances:
singleton
: only one instance will be used. It's lazy instantiatingprovider
: it's create instance every time it's called. Lazy also!constant
: constant value by tag. It's create when it binded
In order to get a value or add a new one to the dependency graph, you need to call the kodi {}
function from any part of your program. Recomendation to call it for binding at MainApplication.kt
class. You can use val myModule = kodiModule { bind<ISomeInstance> with ...}
for separate and organize independent component of your programm. Just call kodi {import(myModule) }
to bind all dependencies from it. Keywords:
bind
: bind string tag or generic typewith
given provided instancebindType
: bind inherit typewith
given provided instanceat
: add instance at scope with string namekodiModule { }
: instantiate module for dependency separationwithScope
: can used only withkodiModule
for bind all instances at selected scope. If there is any scope binding inside this module, it will be used as main scope for this bindings
fun main(args: Array<String>) {
// module with custom scope
val kodiModule = kodiModule {
bind<ISingleInterface>() with single { SingleClass(UUID.randomUUID().toString()) }
// this will be use a `MY_PROVIDER_SCOPE_NAME` scope (since version 1.3.+)
bind<IProviderInterface>() at MY_PROVIDER_SCOPE_NAME with provider { ProviderClass(UUID.randomUUID().toString()) }
// since version 1.2.7
bindType<ISingleInterface, AnotherSingleClass>() with single { AnotherSingleClass(UUID.randomUUID().toString()) }
bindType<ISingleInterface, OneMoreSingleClass>() with single { OneMoreSingleClass(UUID.randomUUID().toString()) }
} withScope MY_SINGLE_SCOPE_NAME.asScope()
kodi {
// Import module
import(kodiModule)
// bind constant value
bind<String>(SOME_CONSTANT_TAG) with constant { "Hello" } at scope(CONSTANTS_SCOPE)
// bind singleton value with lazy receiver properties
bind<IInjectable>() with single { InjectableClass(instance(), instance()) } at MY_SINGLE_SCOPE_NAME.asScope()
// Multi type instance from inherits (since 1.2.7)
val anotherInstance: ISingleInterface = instance<AnotherSingleClass>()
anotherInstance.printName()
// Call Instance of the same interface but another implementation
val oneMoreInstance: ISingleInterface = instance<OneMoreSingleClass>()
oneMoreInstance.printName()
// get value
val singleInstance = instance<ISingleInterface>()
singleInstance.printName()
// immutable variable
val providerImmutableLazyInstance by immutableInstance<IProviderInterface>()
// mutable variable
var providerMutableLazyInstance by mutableInstance<IProviderInterface>()
val injectableSinge = instance<IInjectable>()
// another instance call
instance<IProviderInterface>().printName()
// call immutable variable
providerImmutableLazyInstance.printName()
// call mutable variable
providerMutableLazyInstance.className()
providerMutableLazyInstance = ProviderClass("Another_id", "another name")
//call singleton class as lazy
injectableSinge.providerInstance.printName()
injectableSinge.singleInstance.printName()
// call of mutable instance
providerMutableLazyInstance.printName()
// unbind instance
unbind<IProviderInterface>()
//change instance scope
holder<IInjectable>() at MY_PROVIDER_SCOPE_NAME.asScope()
// unbind all scope of instances and removed it from dependency graph
unbindScope(MY_SINGLE_SCOPE_NAME.asScope())
}
}
interface IPrintable {
val id: String
val name: String
fun printName() {
println("-----> Class name: ${this.name} withScope id: $id")
}
}
interface ISingleInterface : IPrintable
data class SingleClass(override val id: String, override val name: String = "Single") : ISingleInterface
data class AnotherSingleClass(override val id: String, override val name: String = "Another") : ISingleInterface
data class OneMoreSingleClass(override val id: String, override val name: String = "OneMore") : ISingleInterface
interface IProviderInterface : IPrintable, Cloneable
data class ProviderClass(override val id: String, override val name: String = "Provider") : IProviderInterface
interface IInjectable {
val singleInstance: ISingleInterface
val providerInstance: IProviderInterface
}
data class InjectableClass(
override val providerInstance: IProviderInterface,
override val singleInstance: ISingleInterface
) : IInjectable
See com.mincor.kodiexample.KodiTest.kt
for full example.
- KodiReflect library
It's use a kotlin reflect library to create instances and inject parameters into constructor. For start using this you need to implement IKodi
interface to take all features of injection, like lazy property initialization or direct access to instances of given generic classe. It contains some functionality like:
single()
- create the one and only one instace of given generic class and save it in instanceMapinstance()
- simple create an instance of given generic classinstanceByTag()
- create an instance of given generic class and save it to instanceMapprovider()
- it's create or give an holder class for your functions and save it into instanceMap to call laterproviderCall()
- call the providing function with tag, function and paramsproviderCallByTag()
- call already saved provider by tag and paramsbind<Interface, Implementation>(... params)
- you can use binding function to map your interfaces to instance in just one line of code (Sinse version 0.1.5)constant(TAG, VALUE)
- map constants to tag (Sinse version 0.1.5)singleProvider(block: () -> T): T
- to initilize instance by yourself (since version 0.1.9)
You can initialize you instances, single, providers, binding and constants in just one place: val kodi = kodi { }
in every function you can pass params for injection and put a tag to get it later. You can use lazy instantiating by extension functions
- singleLazy
- providerLazy
data class UserData(val id:String, val name:String, val email:String)
data class Post(val id:String = "", val user:UserData? = null, val title:String = "", val desc:String = "")
interface IUserData {
fun getData():String
}
class UserDataInstance : IUserData {
override fun getData():String {
return "HELLO WORLD"
}
}
class MainActivity : AppCompatActivity(), IKodi {
companion object {
const val TAG_FUN_WITH_PARAMS = "fun_with_params"
const val TAG_FUN_WITHOUT_PARAMS = "fun_without_params"
const val TAG_FUN_FOR_INIT = "fun_for_init"
private const val INSTANCE_TAG = "simple_tag"
const val MY_GLOBAL_CONST = "global_const"
}
// now you can initialize Kodi and all the injected dependencies in one place
val kodi = initKODI {
single<UserData>(UUID.randomUUID().toString(), "Aleksandr", "[email protected]")
bind<IUserData, UserDataInstance>()
constant(MY_GLOBAL_CONST, "https://myamazingaddress.com")
provider(TAG_FUN_FOR_INIT, ::checkInstanceWithTag)
}
///-------- LAZY VAL SECTION ----////
private val singleInstance: UserData by singleLazy(UUID.randomUUID().toString(), "Aleksandr", "[email protected]")
private val providerWithReturnAndParams by providerLazy("", ::funcForProviderLazy, UUID.randomUUID().toString())
private val userDataInstance:IUserData by singleLazy()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
println("-----> SINGLE INSTANCE '${singleInstance.name}'")
val posts = mutableListOf<Post>()
(0..25).forEach {
// Only instances with 'var' constructor params can be ovveriden by input params if another case check
posts.add(instance(UUID.randomUUID().toString(), single<UserData>(listOf("1", "2", "3", "4", "5", "6")), "Title $it", "Desc $it"))
}
println("-----> INTERFACE BINDING TEST DATA ${userDataInstance.getData()}")
println("-----> CONSTANTS TEST ${constant<String>(MY_GLOBAL_CONST)}")
val providerData = providerWithReturnAndParams.call()
println("-----> PROVIDER LAZY DATA '${providerData.name}' and email = '${providerData.email}'")
// val instanceWithTag = instanceByTag<Post>(INSTANCE_TAG, UUID.randomUUID().toString(), singleInstance, "Title with tag", "Desc with tag")
// println("-----> INSTANCE WITH TAG TITLE '${instanceWithTag.title}'")
// call the function without params
providerCall(TAG_FUN_WITHOUT_PARAMS, ::funcWithoutParams)
// call the function with params
providerCall(TAG_FUN_WITH_PARAMS, ::funcWithParams, posts)
/**
* If you do not set the incoming function parameters it throw with RuntimeException
*/
// check for singleInstance user
val singleUser = single<UserData>()
val providerWithReturns = providerCall("fun_with_return", ::funcWithReturnAndParams, singleUser)
println("-----> RETURN FROM FUNC '$providerWithReturns'")
/**
* Call the function that we bind early in initKODI section
*/
providerCall<Unit>(TAG_FUN_FOR_INIT)
/**
* Call already bounded function with new params
*/
providerCallByTag<String>(TAG_FUN_WITH_PARAMS, single<UserData>())
//call provider with RuntimeException, cause there is no providing function gives
//providerCallByTag<String>("provider_call_without nothing", "HEHE")
println("-----> END OF PRINTING")
}
private fun checkInstanceWithTag() {
println("-----> HELLO instance with tag and desc = '${instanceByTag<Post>(INSTANCE_TAG).desc}'")
}
fun funcForProviderLazy(id:String):UserData {
return instance(id, "Vasya", "[email protected]")
}
fun funcWithoutParams() {
println("-----> IM WITHOUT PARAMS")
}
fun funcWithParams(posts:Any) {
println("-----> IM WITH PARAMS '$posts'")
}
fun funcWithReturnAndParams(user:UserData):String = user.id
override fun onDestroy() {
// clear all saved instances
removeAll()
super.onDestroy()
}
}
Gradle:
build.gradle {
maven { url = "https://jitpack.io" }
}
// Standart Library
implementation 'com.github.Rasalexman.KODI:kodi:x.y.z'
// AndroidX Module
implementation 'com.github.Rasalexman.KODI:kodiandroidx:x.y.z'
// Annotation processing
kapt 'com.github.Rasalexman.KODI:kodigen:x.y.z'
// Old Reflection Library. It's a final version and i don't have any plans to support it in the future.
implementation 'com.github.Rasalexman.KODI:kodireflect:x.y.z'
License
MIT License
Copyright (c) 2021 Aleksandr Minkin ([email protected])
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.