Gradle flavors, applicationId and not resolved custom view attributes - android-gradle-plugin

Question

I have a custom view based on GridLayout:
package com.mycompany.myapp;
...
public class GridLayoutForceSizeCells extends GridLayout
{
}
I have defined an xml with custom attributes for this class:
<?xml version="1.0" encoding="utf-8" ?>
<resources>
<declare-styleable name="GridLayoutForceSizeCells">
<attr name="totalImages" format="integer" />
<attr name="desiredColumnCount" format="integer" />
<attr name="spacing" format="dimension" />
<attr name="autoGenerate" format="boolean" />
</declare-styleable>
</resources>
Then, I have a layout using this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:wheel="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.mycompany.myapp.GridLayoutForceSizeCells
xmlns:grid="http://schemas.android.com/apk/res/com.mycompany.myapp"
android:padding="3dp"
android:id="#+id/cellsGrid"
android:layout_width="match_parent"
android:layout_height="match_parent"
grid:desiredColumnCount="20"
grid:totalImages="0"
grid:spacing="1dp"
android:orientation="horizontal"/>
</LinearLayout>
The problem I am encountering is that when I change applicationId through a gradle flavor custom attributes are not resolved. I have read in gradlew help that the application package is the one used for R when it is decoupled using gradlew applicationId entry. So, applicationId should not affect my custom attributes package. But when I set applicationId to anything different from com.mycompany.myapp an error arises claiming that attributes can't be resolved.
Has anybody found a solution to this?
Cheers.

Answer 1

Finally fix it using xmlns:grid="http://schemas.android.com/apk/res-auto" to let it resolve the package for me in the layout file instead of the full package name.