Using @string for android:authorities in a ContentProvider

Question

I have a ContentProvider in my manifest, when I define them fully with hardcoded strings it works. E.g.

<provider android:name="com.myprovider" android:authorities="com.myprovider"/>

Works perfect, however the ContentProviders are in a library that gets used by multiple projects, and I don't want authority conflicts, so I attempted to do the following.

<provider android:name="com.myprovider" android:authorities="@string/myProviderAuthority">

This way I should be able to define all my authorities in a single strings.xml file and not have conflicts between apps since I should be able to change them using each apps resource override system.

However, it appears that when I try to build with @string, it gives me a malformed manifest error and says "Provider does not INCUDE (yes it says INCUDE) authorities tribute"

Can I not use a resource string for the authorities tribute, I feel sick everytime I need to maintain constants in two locations. Authority conflicts can be hard to catch by our QA dept, and I don't want things to become out of sync or it could cause confusion. Anybody have any ideas why my code isn't working?

Answer 1

I faced a similar problem but with the android:versionCode attribute. When I tried to define the version code in resources and use a reference to it in the manifest Android Market even forbade me to publish the application. The reason of such behavior turned out to be rather simple. Resources can change depending on current configuration and this value have to be the same in any case.

Probably, this is the reason why content providers with authority references do not work too. And it seems to me that it's not a good idea to use such a reference because there's no guarantee that there will be the only one value for an authority resource in an app. I understand that you can be careful enough to keep a single instance of this resource but there's no special compiler or system checks for this so it cannot be trusted.