Custom attributes in Android fragments

Question

I'd like to define custom attributes in Android fragment using XML (without using bundle additional parameters) like declare-styleable in custom controls. But there are no constructors with AttrSet parameters, so is it possible? Can i just override public void onInflate(android.app.Activity activity, android.util.AttributeSet attrs, android.os.Bundle savedInstanceState) in order to get attributes support?

Answer 1

The Link for Support4Demos is changed or can be changed so posting the complete solution. Here it goes.

1. Create attrs.xml file in res/values folder. Or add the below content if file already exists.

    <?xml version="1.0" encoding="utf-8"?>
    <resources>
    <declare-styleable name="MyFragment">
        <attr name="my_string" format="string"/>
        <attr name="my_integer" format="integer"/>
    </declare-styleable> 
   

2. Override the onInflate delegate of fragment and read attributes in it

    /**
     * Parse attributes during inflation from a view hierarchy into the
     * arguments we handle.
     */
    @Override
    public void onInflate(Activity activity, AttributeSet attrs, Bundle savedInstanceState) {
        super.onInflate(activity, attrs, savedInstanceState);
        Log.v(TAG,"onInflate called");
   
        TypedArray a = activity.obtainStyledAttributes(attrs,R.styleable.MyFragment);
   
        CharSequence myString = a.getText(R.styleable.MyFragment_my_string);
        if(myString != null) {
            Log.v(TAG, "My String Received : " + myString.toString());
        }
   
        int myInteger = a.getInt(R.styleable.AdFragment_my_integer, -1);
        if(myInteger != -1) {
            Log.v(TAG,"My Integer Received :" + myInteger);
        }
   
        a.recycle();
    }
   

3. Pass these attributes in your layout file as following. Just an example

    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
   
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="This is android activity" />
   
        <fragment
            android:id="@+id/ad_fragment"
            android:name="com.yourapp.packagename.MyFragment"
            android:layout_width="fill_parent"
            android:layout_height="50dp"
            android:layout_alignParentBottom="true"
            app:my_string="Hello This is HardCoded String. Don't use me"
            app:my_integer="30" />
   
    </RelativeLayout>
   

Thats all. Its a working solution.

While doing this if you see any namespace error in xml. try project cleaning again and again. This is pathetic but Eclipse and adt misbehaves sometimes.

Answer 2

@Override
public void onInflate(Activity activity, AttributeSet attrs, Bundle savedInstanceState) {
    super.onInflate(activity, attrs, savedInstanceState); 
    // Your code here to process the attributes
}