Unresolved reference when importing views from a submodule using kotlin-android-extensions

Question

When I try to use kotlin-android-extendions' view injection in a multi-module application I get an error injecting a view from an android.library submodule:

Unresolved reference: component_xyz_user_name

We have a main app module and an android.library submodule subm. App module references subm. Both of these modules use databinding, kapt and android-extensions.

In both modules gradle files contain:

apply plugin: 'com.android.library' //or com.android.application
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'

android {
    [...]

    dataBinding.enabled = true
    androidExtensions.experimental = true
}

In subm library we define component_user_info.xml view defined like so:

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools">

    <data> [...] </data>

    <android.support.constraint.ConstraintLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/component_xyz_user_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    </android.support.constraint.ConstraintLayout>
</layout>

where component_xyz_user_name is the view that we're gonna inject in the next step.

In main app we define a fragment_main.xml view like so:

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>[...]</data>

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/news_details_coordinator_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true">

        <include layout="@layout/component_user_info"
            />

    </android.support.design.widget.CoordinatorLayout>
</layout>

with a ViewModel MainFragmentViewModel defined in the following manner:

import kotlinx.android.synthetic.main.component_user_info.*

class MainFragment : Fragment() {

    fun updateUserInfo() {
        component_xyz_user_name.text = "ABCDEF"
    }
}

Compilation FAILS with the following error:

e: /Users/user/repos/project/app/src/main/java/com/company/users/MainFragment.kt: (108, 9): Unresolved reference: component_xyz_user_name
e: /Users/user/repos/project/app/src/main/java/com/company/users/MainFragment.kt: (109, 9): Unresolved reference: component_xyz_user_name

Why do I get Unresolved reference: component_xyz_user_name. Is there any workaround for this?

EDIT:

As a temporary workaround I've written the following extension function for Activity & Fragment:

/**
 * Find view in an activity
 */
fun <T : View> Activity.v(@IdRes resId: Int): T = findViewById(resId)

/**
 * Find view in a fragment
 */
fun <T : View> Fragment.v(@IdRes resId: Int): T = activity.findViewById(resId)

so that I can :

fun updateUserInfo() {
    v<TextView>(R.id.component_xyz_user_name).text = "ABCDEF"
}

Farrel

Possible duplicate of Kotlin Android Extension layouts from library module cannot be resolved – Decennial

Have you tried walking the hierarchy. Typically when you have an include you have to access it via dot notation. mainFragBinding.childLayout.txtBox. I understand synthetic imports should work, but it's only saving you a couple dot walks, so I would try without the synthetic import to ensure there aren't issues there. Also you may need to give your include an ID to access it by name. – Losse

thanks problem was in kotlin extension, if use findViewById, it's work and can see views between modules. – Brabazon

Answer 1

I had a similar problem - I added a submodule using git and I was not able to access it in the kotlin files, so what I had to add in the build.gradle was this part:

sourceSets {

    main {
        java {
            srcDir 'src/main/java/module_folder'
        }
    }
}

and this had to be in the main android object

Daffie