Angular JS observe on directive attribute

Angular JS observe on directive attribute

How can angular js watch attributes on custom directive in order to accept
angular values to be bind
Here is what I have so far:
app.directive('tile', [function(){ return { restrict: 'E', link:
function(scope, element, attrs) { var title = attrs.title;
attrs.$observe('dataValue', function(val) {
var data = val;
console.log(data);
var dom =
"<div>" +
"<p>" + title + "</p>" +
"<p>" + data + "</p>" +
"</div";
$(element).append($(dom.trim()));
});
}
};
}]);
but the observed value is coming back as undefined