Angularjs 根据一个select的值去设置另一个select的值方法

<div ng-controller="myselectcontroller">
<select ng-model="myfield" ng-options="field.label for field in names" 
ng-change="myselectcontrollerchange()">
<option value=''>{{'select.label.vxi.custom.select' | translate}}</option>
</select>
</div>
 <div ng-controller="myrelationcontroller">
<select ng-model="myrelation" ng-options="relation.name for relation in relationlist" >
<option value=''>{{'select.label.vxi.custom.select' | translate}}</option>
</select>
</div>

var myselectcontroller=['$scope', '$http', '$rootscope', function($scope, $http, $rootscope) {
 
 //$http的method可以是get/delete/head/jsonp/post/put
 //$http服务快捷的get请求
 //alert('root=='+activiti.config.contextroot);//对应/activiti-explorer/service
 $http({
 method:'put',
 url:activiti.config.contextroot +'/getformfieldlist'
 })
 .success(
 function(data,status,headers,config){
 //成功加载
   $scope.names=data;
 })
 .error(
 
 function(data,status,headers,config){
 //处理错误
 //do nothing
 }
 );
 //change
 $scope.myselectcontrollerchange=function(){
 var app=angular.module('activitimodeler',[]);
 if($scope.myfield.optiongroupid!=null && $scope.myfield.optiongroupid!=''){
 //有optiongroup
 console.log('if');
 $rootscope.relationlist = [{id:0,name:'等于'},{id:1,name:'不等于'},{id:2,name:'包含'}];
 }else{
 //没有optiongroup
 console.log('else');
 $rootscope.relationlist = [{id:0,name:'等于'},{id:3,name:'大于'},{id:4,name:'小于'},{id:5,name:'小于等于'},{id:6,name:'大于等于'},{id:2,name:'包含'}];
 }
 
 }
 
}
];

//change
 $scope.myselectcontrollerchange=function(){
 var data=null;
 if(null==$scope.mycolumnselectmodel){
 data={
  pa:'',
  pb:''
 };
 }else{
 data={
  pa:$scope.mycolumnselectmodel,
  pb:$scope.mycolumnselectmodel.optiongroupid
 };
 }
 $scope.$emit('to_myparentcontroller_on_mycolumnselectmodel_change',data);
 }
 
/*myparentcontroller*/
angular.module('activitimodeler').controller('myparentcontroller',['$rootscope', '$scope', '$http', '$timeout','$window', function ($rootscope, $scope, $http, $timeout,$window) {
 //选择字段下拉列表，触发关系符下拉
 $scope.$on('to_myparentcontroller_on_mycolumnselectmodel_change',function(event,data){
 $scope.$broadcast('to_myrelationcontroller_on_mycolumnselectmodel_change',data);
 });
 
 
}]);
 
/*关系符*/
angular.module('activitimodeler').controller('myrelationcontroller',['$rootscope', '$scope', '$http', '$timeout','$window', function ($rootscope, $scope, $http, $timeout,$window) {
 $scope.myrelationdisablevar=true;
 $scope.objdisabletrue=true;//加上灰背景
 //接收事件-根据字段显示下拉
 $scope.$on('to_myrelationcontroller_on_mycolumnselectmodel_change',function(event,data){
 if(data.pa!=''){
 $scope.myrelationdisablevar=false;
 $scope.objdisabletrue=false;//去掉灰背景
 if(data.pb!=null && data.pb!=''){
 //有optiongroup
 $scope.relationlist = [{id:0,name:'等于'},{id:1,name:'不等于'},{id:2,name:'包含'}];
 }else{
 //没有optiongroup
 $scope.relationlist = [{id:0,name:'等于'},{id:3,name:'大于'},{id:4,name:'小于'},{id:5,name:'小于等于'},{id:6,name:'大于等于'},{id:2,name:'包含'}];
 }
 }else{
 $scope.relationlist=null;
 $scope.myrelationdisablevar=true;
 $scope.objdisabletrue=true;//加上灰背景
 }
 
 });
 
}]);