Android DataBinding Custom Binding Adapter Warning

Question

I followed the data binding documentation for Custom Binding Adapter for image loading from official Android Developers site: http://develo

Answer 1

I believe the namespace is truly ignored in the BindingAdapter annotation. The warning occurs if you use any namespace prefix, regardless of whether it matches the one used in your layout or not. If you omit the namespace, like so:

@BindingAdapter({"imageUrl"})

...the warning doesn't occur.

I suspect the warning exists to alert us the namespace is stripped off before the string is used as a key in the annotation's implementation. Which makes sense when you consider layouts are free to declare whatever namespaces they want, e.g. app: or bind: or foo:, and the annotation needs to work across all those cases.