difference in naming xml between res-auto and com.package.name - android

Question

I have seen custom xml with :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res-auto"

and

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/com.package.custom"

whats the difference between these two separate names?

1. Is the latter only points to default location like your package?
2. Is the former points to the reference lib ?

thanks.

Answer 1

If we add a new custom view and its attributes inside our project, you add this at the beginning of your layout:

xmlns:custom="http://schemas.android.com/apk/res/your_main_app_package

If the new custom view is inside a library project linked to your project, you add this:

xmlns:custom="http://schemas.android.com/apk/res-auto

Note: This problem has been fixed in ADT revision 17+ . For any services or Activities, declare the namespace as follows:

xmlns:custom="http://schemas.android.com/apk/res-auto"

The suffix res-auto will be replaced at build time with the actual project package, so make sure you set up your attribute names to avoid collisions if at all possible.