grafana/public/app/plugins/datasource/cloudwatch/query_ctrl.js

define([
  'angular',
  'lodash',
],
function (angular, _) {
  'use strict';

  var module = angular.module('grafana.controllers');

  module.controller('CloudWatchQueryCtrl', function($scope) {

    $scope.init = function() {
      $scope.aliasSyntax = '{{metric}} {{stat}} {{namespace}} {{region}} {{<dimension name>}}';
    };

    $scope.refreshMetricData = function() {
      if (!_.isEqual($scope.oldTarget, $scope.target)) {
        $scope.oldTarget = angular.copy($scope.target);
        $scope.get_data();
      }
    };

    $scope.init();

  });

});