Android data binding: can't find setter for attribute android:onClick

Question

I'm getting this error:

Cannot find the setter for attribute 'android:onClick' with parameter type android.view.View.OnClickListener on android.widget.Button. file:/home/itstym/ApkProjects/Reminder/app/src/main/res/layout/activity_main.xml loc:54:27 - 54:61

activity.main.xml

<data class="ActivityMainBinding">
        <variable
            name="login"
            type="com.example.itstym.reminder.loginViewModel" />

        <variable
            name="handler"
            type="com.example.itstym.reminder.LoginHandler" />
    </data>

     <Button
    android:onClick="@{(v) -> handler.onLoginButtonClicked(v,login)}"
    android:id="@+id/submit_button"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginEnd="16dp"
    android:layout_marginStart="16dp"
    android:layout_marginTop="24dp"
    android:text="Sign In"
    app:layout_constraintEnd_toEndOf="@+id/user_password"
    app:layout_constraintStart_toStartOf="@+id/user_password"
    app:layout_constraintTop_toBottomOf="@+id/user_password"/>

MainActivity.java

val handler= LoginHandler(this@MainActivity)

LoginHandler.kt

class LoginHandler(context:Context) {

    fun onLoginButtonClicked(view:View, userInfo: loginViewModel) {
        Log.i("Email is ", userInfo.userEmailAddress)
        Log.i("Password is ", userInfo.userPassword)
    }
}

How do I create the setter for the button here? I think I am creating it only for the view, but not for the button setter.

Stacktrace

at android.databinding.tool.processing.Scope.assertNoError(Scope.java:112)
    at android.databinding.annotationprocessor.ProcessDataBinding.process(ProcessDataBinding.java:91)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:794)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$200(JavacProcessingEnvironment.java:91)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment$DiscoveredProcessors$ProcessorStateIterator.runContributingProcs(JavacProcessingEnvironment.java:627)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1033)
    at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1198)
    at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1170)
    at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1068)
    at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:73)

Any leads will help!

Answer 1

Your xml should be like this

<data class="ActivityMainBinding">
    <variable
        name="login"
        type="com.example.itstym.reminder.loginViewModel" />

    <variable
        name="handler"
        type="com.example.itstym.reminder.MainActivity" />
</data>

     <Button
        android:onClick="@{(v) -> handler.onLoginButtonClicked(v, login)}"
        android:id="@+id/submit_button"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="24dp"
        android:text="Sign In"
        app:layout_constraintEnd_toEndOf="@+id/user_password"
        app:layout_constraintStart_toStartOf="@+id/user_password"
        app:layout_constraintTop_toBottomOf="@+id/user_password"/>

You can directly get this onClick in your MainActivity . There is no need to create a separate class.

MainActivity.java

ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
binding.setHandler(this);      

Then in MainActivity you can access this method like:

public void onLoginButtonClicked(View view, LoginViewModel model) {
   //Do something
}