Twitter url is not recalculated once she is defined

In a angular webapp, if we navigate in tabs, the main template in which is  included the directive does not change but the url is.
This creates a problem for twitter due to the code at line 70:
scope.status = scope.status || ("Check this out! - " + url);

For my usage, it should only be:
scope.status = "Check this out! - " + url

Thanks for good job :)
