Android two way binding with Integer type causes databinding does not exist

Question

I'm having some issue with implementing two way binding with an Integer data type.

public class User {

    private String firstName;
    private String lastName;
    private int age;

    public User() {}

    public void setFirstName(String firstName) {
       this.firstName = firstName;
    }

    public String getFirstName() {
       return this.firstName;
    }

    public void setLastName(String lastName) {
       this.lastName = lastName;
    }

    public String getLastName() {
       return this.lastName;
    }

    public void setAge(int age) {
       this.age = age;
    }

    public int getAge() {
       return this.age;
    }

}

XML:

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

    <data class="UserDataBinding">
        <variable
            name="user"
            type="com.databinding.model.User" />
    </data>

    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="@dimen/activity_horizontal_margin">

       <EditText android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@={user.firstName}" />

       <EditText android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@={user.lastName}" />

       <EditText android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@={user.age}" />

    </LinearLayout>
</layout>

Unfortunately, it gives me the error

"Error:(52, 17) Cannot find the getter for attribute 'android:text' with value type java.lang.Integer on android.support.design.widget.TextInputEditText. "

If I change the attribute text to

       <EditText android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@={Integer.toString(user.age)}" />

then I get the error

"Error:cannot generate view binders java.lang.NullPointerException"

Appreciate any help on this.

UPDATE: It seems there was another error right after the error mentioned above.

cannot generate view binders java.lang.NullPointerException

Not sure why its giving me NPE even though the app hasn't started yet.

Answer 1

Well, six months later but maybe i can help someone.

You can do this simple trick:

android:text="@={`` + mObject.someNumber}"

OBS.: You need at least Android Studio 2.3

Answer 2

android:text="@{String.valueOf(Integer)}"

Answer 3

Somehow I got this to work by using BindingAdapter and InverseBindingAdapter.

public class User {

    private String firstName;
    private String lastName;
    private int age;

    public User() {}

    public void setFirstName(String firstName) {
       this.firstName = firstName;
    }

    public String getFirstName() {
       return this.firstName;
    }

    public void setLastName(String lastName) {
       this.lastName = lastName;
    }

    public String getLastName() {
       return this.lastName;
    }

    public void setAge(int age) {
       this.age = age;
    }

    public int getAge() {
       return this.age;
    }

    @BindingAdapter("android:text")
    public static void setText(TextView view, int value) {
        view.setText(Integer.toString(value));
    }

    @InverseBindingAdapter(attribute = "android:text")
    public static int getText(TextView view) {
        return Integer.parseInt(view.getText().toString());
    }
}

Hopefully this will help someone else as well.