Thinking button in angular

btn-thinking.js

'use strict';

angular.module('app.common').directive('btnThinking', function($compile) {
    return {
        restrict: 'A',
        link: function (scope, element, attrs)
        {
            var html = element.html();

            attrs.$observe('btnThinking', function(thinking) {

                thinking = scope.$eval(thinking);

                if (thinking) {
                    element.attr('disabled', true);
                    element.html('<i class="glyphicon glyphicon-refresh"></i>');
                    element.addClass('btn-thinking');
                } else {
                    element.attr('disabled', false);
                    element.html(html);
                    $compile(element.contents())(scope);
                    element.removeClass('btn-thinking');
                }
            });

        }
    };
});