Grunticon embedder for use in Angular directives/templates

ng-grunticon-embed.directive.js

/* globals grunticon: false */

(function() {
    'use strict';

    angular.module('ngGrunticon', [])
        .provider('grunticonEmbedConfig', function() {
            this.gruntIcons = undefined;

            this.init = function(grunticonCss) {
                var css = grunticon.getCSS(grunticonCss);
                css = css ? css : window.document.querySelector('[data-grunticon-css]');

                if (css) {
                    this.gruntIcons = {};
                    
                    var icons = grunticon.getIcons(css);
                    Object.keys(icons).forEach(function(key) {
                        var selector = key.slice('grunticon:.'.length);
                        this.gruntIcons[selector] = icons[key];
                    }, this);
                }
            };

            this.$get = function() {
                return this;
            };
        })
        .directive('grunticonEmbed', function($log, grunticonEmbedConfig) {
            return {
                restrict: 'A',
                scope: {
                    grunticonEmbed: '@'
                },
                controller: function($scope, $element) {
                    $scope.$watch('grunticonEmbed', function(newClass, oldClass) {
                        if (oldClass) {
                            $element.removeClass(oldClass);
                        }

                        if (newClass) {
                            $element.addClass(newClass);
                        }
                        
                        embedIcon($element);
                    });
                }
            };

            function embedIcon(element) {
                if (grunticonEmbedConfig.gruntIcons) {
                    var classListArray = element[0].classList.toString().split(' ');
                    var icons = arrayIntersection(classListArray, Object.keys(grunticonEmbedConfig.gruntIcons));

                    if (icons.length === 1) {
                        element[0].innerHTML = grunticonEmbedConfig.gruntIcons[icons[0]];
                        element[0].style.backgroundImage = 'none';
                    }
                } else {
                    $log.error('Grunticon CSS not configured! please use ' +
                        '\'grunticonEmbedConfigProvider.init()\' to configure.');
                }
            }
        });

    // Utility
    function arrayIntersection(array1, array2) {
        return array1.filter(function(n) {
            return array2.indexOf(n) !== -1;
        });
    }

})();

Gist updated to support dynamic class name + other improvements.

Dynamic class name:

Ideally, we would like the embedded to work with DOM element which has ng-class in them to select dynamically the name of the icon to show. However, we couldn't make our embedded to work after ng-class has finished injecting the classes to the DOM element. Therefore, we had to do some workaround:

Not working: <div ng-class="myIcon" data-grunticon-embed>
Working: <div data-grunticon-embed="{{ myIcon }}">

If anyone has a better idea we would love to hear