Angular canvas directive. Demo at http://plnkr.co/edit/fMjsBr?p=preview

ng-canvas.js

(function(angular) {
  "use strict";
  angular.module("ng.canvas", [])
    .directive('canvas', ["$timeout",
      function($timeout) {
        return {
          restrict: "E",
          link: function(scope, elm , attrs ) {
            scope[attrs.context2d||"context2d"]=elm[0].getContext("2d");
            $timeout(function(){scope.$eval(attrs.init||"canvasInit()")});
          }
        };
      }
    ]);
})(angular);