It would be helpful if we could have application/x-www-form-urlencoded supported. It's common when using Android to include parameters in the body with this encoding but XData complains that it is not supported. For example:
from the Android code
@FormUrlEncoded
@POST("LoginService/Login")
Observable login( @Field("username") String username, @Field("password") String password );
gives an EXDataHttpUnsupportedMediaType exception from within XData