How to compare strings in xml file using databinding

Question

How can I compare my object String field value to another String value in xml file using databinding? Is it possible to do so in xml file or should I create a method somewhere in my project with @BindingAdapter annotation? Below is what I've tried so far and it didn't worked. It would also be good to compare with String resource value and not with hardcoded string value.

<RadioGroup
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <RadioButton
                android:id="@+id/male"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:checked="@{user.gender.equalsIgnoreCase("male")}"
                android:text="@string/male"/>

            <RadioButton
                android:id="@+id/female"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:checked="@{user.gender.equalsIgnoreCase("female")}"
                android:text="@string/female"/>

        </RadioGroup>

Thanks for help.

Answer 1

You have it almost correct. String constants can't use double-quotes within double-quotes in XML, so android data binding supports using back-quote in the expression:

        <RadioButton
            android:id="@+id/male"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked="@{user.gender.equalsIgnoreCase(`male`)}"
            android:text="@string/male"/>

That allows you to mix character constants with single-quotes along with string constants.

XML also allows the use of single quotes for attribute values, so you can use double quotes within the expression. This is the more common approach:

        <RadioButton
            android:id="@+id/female"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked='@{user.gender.equalsIgnoreCase("female")}'
            android:text="@string/female"/>

You can skip the whole thing and use string resources or constants:

        <RadioButton
            android:id="@+id/male"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked="@{user.gender.equalsIgnoreCase(@string/male)}"
            android:text="@string/male"/>

        <RadioButton
            android:id="@+id/female"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:checked="@{user.gender.equalsIgnoreCase(StringConstants.FEMALE)}"
            android:text="@string/female"/>