interval.promises.html

## interval.promises.html
<html>
  <head>
    <title>Interval Example - Ticker and Promises</title>
    <script type="text/javascript" src="https://code.angularjs.org/1.4.0-rc.2/angular.js"></script>
  </head>
  <body ng-app="calculatorApp">
    <div ng-controller="CalculatorController">
      Ticker: {{ticker}}
      <br><br>
      <label>From:</label>
      <input type="number" ng-model="from">
      <label>Inc:</label>
      <input type="number" ng-model="inc">
      <input type="button" value="Start" ng-click="start()">
      <input type="button" value="Cancel" ng-click="cancel()">

      <h4>Debug Output</h4>
      <div>{{debug}}</div>
    </div>
    <script type="text/javascript">

      var app = angular.module('calculatorApp', []);

      app.controller('CalculatorController', function calculatorController($scope, $interval) {

        var counterInstance;
        var counterFunction = function(start, inc) {
          if ($scope.ticker === 0 && start)
            $scope.ticker = start;

          if (!inc)
            inc = 1;

          $scope.ticker += inc;
        }

        var debugOutput = function(msg) {
          // logging for demo
          $scope.debug += msg + ' * ';
        }

        // defaults
        $scope.ticker = 0;
        $scope.from = 0;
        $scope.inc = 1;

        $scope.start = function() {
          $scope.debug = '';
          counterInstance = $interval(counterFunction, 500, 3, true, $scope.from, $scope.inc);
          debugOutput('Starting status: ' + counterInstance.$$state.status);

          counterInstance.then(function(successCallback, errorCallback, notifyCallback) {
            debugOutput('The interval was executed: ' + successCallback + ' times!');
            debugOutput('Then status: ' + counterInstance.$$state.status);
            // errorCallback (always undefined for interval)
            // notifyCallback (always undefined for interval)
          });

          counterInstance.catch(function(errorCallback) {
            // called when the interval is cancelled
            if (errorCallback === 'canceled') {
              debugOutput('The interval was cancelled!');
            } else {
              debugOutput('Something else went wrong!');
            }
            debugOutput('Catch status: ' + counterInstance.$$state.status);
          });

          counterInstance.finally(function() {
            // always called regardless
            // Status values:
            //    0 for running
            //    1 for done
            //    2 for cancelled
            debugOutput('Finally status: ' + counterInstance.$$state.status);
            counterInstance = undefined;
          });

        }

        $scope.cancel = function() {
          if (angular.isDefined(counterInstance)) {
            $interval.cancel(counterInstance);
          }
        }

        $scope.$on('$destroy', function() {
          $scope.cancel();
        });

      });

    </script>

  </body>
</html>