I have the following route :

```
this.route('groupPage', {
path: '/group/:_groupId',
waitOn: function(){
return Meteor.subscribe("groupPage", this.params._groupId);
},
data: function() {
var group = Groups.findOne({_id: this.params._groupId});

var members = Meteor.users.find({_id : {$in: group.memberIds}}); ******** ISSUE HERE******

return {
group: group,
members: members,

}; }});

```

and the following publication :

```
Meteor.publishComposite('groupPage', function(groupId, sortOrder,    limit) {
return {
// return the group
find: function() {

    if(this.userId){
      var selector = {_id: groupId};
      var options = {limit: 1};

      return  Groups.find(selector, options);
    }
    else{
      return ;
    }
 },

children: [

    {  // return the members
      find: function(group) {

          var selector = {_id: {$in: group.memberIds} };
          return Meteor.users.find(selector);
      }
    }
 ]}}) ;

```

Now my issue is that : when the related page renders for the first there is no problems but when i actualize the group Page view the line : var members = Meteor.users.find({\_id : {$in: group.memberIds}}); gives me the error : undefined object don't have memberIds property. i guess it's because the subscription is not yet ready when doing group.memberIds , isn't it ? Please a hint.
Thanks.