Generates mutable models from immutable definitions, simplifying state updates and reducing boilerplate code. Inspired by Redux and Immer, offers atomic field updates and reactive immutable value updates using `StateFlow`.
(Pronunciation: /mjuːˈteɪt/, 'k' is silent)
Generates mutable models from immutable model definitions. It's based on Kotlin's Symbol Processor (KSP). This is inspired from the concept Redux and Immer from JS world that let you write simpler immutable update logic using "mutating" syntax which helps simplify most reducer implementations. So you just need to focus on actual development and Mutekt will write boilerplate for you! 😎
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Try out the example app to see it in action.
Declare a state model as an interface and apply @GenerateMutableModel annotation to it.
Example:
@GenerateMutableModel
interface NotesState {
val isLoading: Boolean
val notes: List<String>
val error: String?
}
// You can also apply annotation `@Immutable` if using for Jetpack Compose UI model.
Once done, 🔨Build project and mutable model will be generated for the immutable definition by KSP.
The mutable model can be created with the factory function which is generated with the name of an interface with prefix
Mutable.
For example, if interface name is ExampleState then method name for creating mutable model will be
MutableExampleState() and will have parameters in it which are declared as public properties in the interface.
/**
* Instance of mutable model [MutableNotesState] which is generated with Mutekt.
*/
private val _state = MutableNotesState(isLoading = true, notes = emptyList(), error = null)
fun setLoading() {
_state.isLoading = true
}
fun setNotes() {
_state.update {
isLoading = false
notes = listOf("Lorem Ipsum")
}
}
Note
Use methodupdate{}on Mutable model instance to mutate multiple fields atomically.
To get immutable instance with reactive state updates, use method asStateFlow() which returns instance of
StateFlow<T>.
Whenever any field of Mutable model is updated with new value, this StateFlow gets updated with new immutable state value.
val state: StateFlow<NotesState> = _state.asStateFlow()
equals() and hashCode()
already overridden.In order to support code generation at compile time, enable KSP support in the module.
plugins {
id 'com.google.devtools.ksp' version '1.7.10-1.0.6'
}
In build.gradle of app module, include this dependency
repositories {
mavenCentral()
}
dependencies {
implementation("dev.shreyaspatil.mutekt:mutekt-core:$mutektVersion")
ksp("dev.shreyaspatil.mutekt:mutekt-codegen:$mutektVersion")
// Include kotlin coroutine to support usage of StateFlow
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
}
In build.gradle.kts of project module:
kotlin {
sourceSets {
val commonMain by getting {
dependencies {
implementation("dev.shreyaspatil.mutekt:mutekt-core:$mutektVersion")
}
}
}
}
dependencies {
add("kspCommonMainMetadata", "dev.shreyaspatil.mutekt:mutekt-codegen:$mutektVersion")
}
tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
if (name != "kspCommonMainKotlinMetadata") {
dependsOn("kspCommonMainKotlinMetadata")
}
}
You can find the latest version and changelogs in the releases.
In order to make IDE aware of generated code, it's important to include KSP generated sources in the project source sets.
Include generated sources as follows:
kotlin {
sourceSets {
main.kotlin.srcDirs += 'build/generated/ksp/main/kotlin'
test.kotlin.srcDirs += 'build/generated/ksp/test/kotlin'
}
}
kotlin {
sourceSets.main {
kotlin.srcDir("build/generated/ksp/main/kotlin")
}
sourceSets.test {
kotlin.srcDir("build/generated/ksp/test/kotlin")
}
}
android {
applicationVariants.all { variant ->
kotlin.sourceSets {
def name = variant.name
getByName(name) {
kotlin.srcDir("build/generated/ksp/$name/kotlin")
}
}
}
}
android {
applicationVariants.all {
kotlin.sourceSets {
getByName(name) {
kotlin.srcDir("build/generated/ksp/$name/kotlin")
}
}
}
}
kotlin {
sourceSets {
val commonMain by getting {
kotlin.srcDirs("build/generated/ksp/metadata/commonMain/kotlin")
}
}
}
Clone this repository and import in IntelliJ IDEA (any edition) or Android Studio.
mutekt-core: Contain core annotation and interface for mutektmutekt-codegen: Includes sources for generating mutekt code with KSPexample: Example application which demonstrates usage of this library../gradlew build../gradlew spotlessCheck../gradlew spotlessApply.Read contribution guidelines for more information regarding contribution.
Have any questions, doubts or want to present your opinions, views? You're always welcome. You can start discussions.
Copyright 2022 Shreyas Patil
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance the License.
You may obtain a copy of the License at
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distributed under the License distributed an BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express implied.
See the License the specific language governing permissions
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