I had the same problem because I was trying to access the class in the other module. It fixed when I put the class I was trying to access into the module containing xml. You can access only the classes in that module from within the XML.

I’ve got a multi module project where the app module contains my binding adapters and my feature module depends on my app module since it is a dynamic feature module.

App (contains binding adapters) —-> Dynamic feature module (where the layout is present)

I have databinding and kapt enabled in all the modules.

I’m unable to build the app successfully. Android Studio gives me the following error,

error: cannot find symbol
import com.app.module1.databinding.FeatureItemBindingImpl;

Layout file in dynamic feature module:

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

    <data>

        <variable
            name="item"
            type="com.app.module1.views.FeatureItem" />

        <variable
            name="clickListener"
            type="com.app.module1.views.FeatureRecyclerViewAdapter.FeatureItemClickListener" />
    </data>

    <com.google.android.material.card.MaterialCardView xmlns_android="http://schemas.android.com/apk/res/android"
        android_layout_width="match_parent"
        android_layout_height="100dp"
        android_layout_margin="10dp"
        app_cardElevation="3dp"
        android_id="@+id/card"
        android_onClick="@{(view) -> clickListener.onClickFeature(view, item)}">

        <LinearLayout
            android_layout_width="match_parent"
            android_layout_height="match_parent"
            android_orientation="vertical">

            <androidx.appcompat.widget.AppCompatImageView
                android_id="@+id/feature_image"
                android_layout_width="match_parent"
                android_layout_height="0dp"
                android_layout_weight="7"
                android_scaleType="fitXY"
                app_set_image="@{item.featureImage}"
                tools_src="@color/green_200" />

            <com.google.android.material.textview.MaterialTextView
                android_id="@+id/feature_name"
                style="@style/TextAppearance.MyTheme.Body2"
                android_layout_width="match_parent"
                android_layout_height="wrap_content"
                android_layout_gravity="center_vertical"
                android_layout_weight="1"
                android_gravity="center"
                android_text="@{item.featureName.featureTitle}"
                tools_text="Order Pills" />
        </LinearLayout>

    </com.google.android.material.card.MaterialCardView>
</layout>

Binding Adapter in the App module:

@BindingAdapter("set_image")
fun AppCompatImageView.setImageToImageView(@DrawableRes drawable: Int) {
    this.setImageResource(drawable)
}