Dagger and Kotlin. Dagger doesn't generate component classes - kotlin

Question

I'm new with kotlin and Dagger. I have a little problem that I do not how to solve and I don't find a solution.
So this is what I have:
#Module
class AppModule (app: Application) {
private var application: Application;
init {
this.application = app;
}
#Provides fun provideApplication(): Application? {
return application;
}
#Provides fun provideResources(): Resources? {
return application.resources;
}
}
#Singleton
#Component(modules = arrayOf(AppModule::class))
interface AppComponent: AppComponentBase {
public class Initializer {
private constructor(){}
companion object {
fun Init(app: Application): AppComponent? {
return DaggerAppComponent.builder().appModule(AppModule(app)).build()
}
}
}
}
AppComponentBase: This interface contain all the methods needed by this component.
Now, the problem is that this DaggerAppComponent class is not generated by Dagger if I do this DaggerAppComponent.builder().appModule(AppModule(app)).build() invocation within the companion object.
If a invoke the same line any were by the companion object dagger generate de class without any problem.
An other thing I did look for a solution was create an other different class with the same structure, and importe the DaggerAppComponent as internal object, and I the same result happened.
I don't what to have the initialization of the component outside. So, there any other alternative solution, or what am I doing wrong?.

Answer 1

You need to have the kapt processor in build.gradle:
kapt {
generateStubs = true
}
dependencies {
...
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
compile 'com.google.dagger:dagger:2.0.2'
kapt 'com.google.dagger:dagger-compiler:2.0.2'
...
}
This extension will generate the code for dagger.
Additionally, for newer gradle versions, you can also apply the plugin in your build.gradle:
apply plugin: 'kotlin-kapt'
dependencies {
...
compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
compile 'com.google.dagger:dagger:2.0.2'
kapt 'com.google.dagger:dagger-compiler:2.0.2'
...
}
You can check this project for reference

Answer 2

I don't know when this change happened, but on 1.1.2 of the Kotlin gradle plugin you replace this (in your module's build.gradle):
kapt {
generateStubs = true
}
with this:
apply plugin: 'kotlin-kapt'
and then make sure to replace dependencies that use annotationProcessor with kapt.
For example, the old way would be to use:
annotationProcessor (
'some.library:one:1.0'
...
'some.library.n:n.0'
)
and now you use:
kapt (
'some.library:one:1.0'
...
'some.library.n:n.0'
)

Answer 3

UPDATE FOR KOTLIN 1.1.4
generateStubs does not work anymore. Feel free to make a build with the latest Kotlin and it would tell you in the Messages section of Android Studio that it is not necessary anymore. Here's an up-to-date list of dependencies for Dagger2 for Android and Kotlin
apply plugin: 'kotlin-kapt'
//...
// Other Gradle stuff
//...
dependencies {
compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:1.1.4-3"
compile 'com.google.dagger:dagger-android:2.12'
kapt 'com.google.dagger:dagger-android-processor:2.12'
compileOnly 'com.google.dagger:dagger:2.12'
kapt 'com.google.dagger:dagger-compiler:2.12'
}

Answer 4

This issue can be fixed with the bellow change which is different from original answer
Following will also work well to fix this issue
with plugins
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'
and dependencies
implementation "com.google.dagger:dagger:$dagger_version"
implementation "com.google.dagger:dagger-android:$dagger_version"
implementation "com.google.dagger:dagger-android-support:$dagger_version"
kapt "com.google.dagger:dagger-compiler:$dagger_version"
kapt "com.google.dagger:dagger-android-processor:$dagger_version"
For reference check out this Gist

Answer 5

Use these dependencies if you are using kotlin as the primary language for android application development
// Dagger dependencies
def dagger_version = "2.44"
implementation "com.google.dagger:dagger:$dagger_version"
kapt "com.google.dagger:dagger-compiler:$dagger_version"
implementation "com.google.dagger:dagger-android:$dagger_version"
implementation "com.google.dagger:dagger-android-support:$dagger_version" // if you use the support libraries
kapt "com.google.dagger:dagger-android-processor:$dagger_version"

Answer 6

My case must be some exclusion rule in Dagger's implementation
com.mycompany.native -> Dagger doesn't generate code
com.mycompany.other -> Dagger generates code
I wasted quite some time on this :-( I hope it helps someone else!

Answer 7

Sorry, I didn’t create a new issue, but decided to answer under similar questions, because maybe someone find it useful!
I faced to ridiculous issue! «Make Project» do not generate dagger files. They are generated while preparing run your App! But I was trying to solve problem for hours and didn't think of simple trying to click Run..)))
So, maybe you faced to the same problem:
Neither «Sync Project with Gradle» nor «Clean» and «Build Project» help generate dagger files.
-> Then just Run your App!
After the first Run App my Dagger started generated files if I click Make Project.

Answer 8

If u have problem withe DaggerComponent, You should add
apply plugin: 'kotlin-kapt'
kapt {
generateStubs = true
}
to build.gradleit will generate kotlin code for dagger 2 otherwise project will only build on Rebuild