node / angular2服务将值返回错误的组件

Question

I am new to nodejs/angular2. I am having a strange issue with Async behavior of node and its return to an angular service. The issue I am having is two different angular components say component A and component B have the same angular service injected in them.

The server side is an async node server which takes some time to complete the request.The problem is when the app routes from angular component A to angular component B, sometimes the request to node completes from component A but since we are currently routed to component B the response goes there. (Component A and B are not visible at the same time. Only one is visible at a time)

Because component B is also subscribed to the same service/method it will get the return result that was designated for component A. Resulting in incorrect values.

Is there a way from Component B to only receive the responses to the requests it sent out.

Both are components are subscribed to the same method within the service as such:

The code is way to big to put on here so I am going to do snippets.

Here is the code that is in each component.

getNode(){

    this.userService.getNode().subscribe(resNodeData => {
    this.node = resNodeData; 
            if(this.node == null){
            return null;
        }
        else{
     // console.log(this.node);  
            }
        });

}

Code from Service Layer:

export class UserService {
  //call to node server async
 getNode() {
return this.http.get("http://" + host + ":3000/api/namenode/"  + this.clusterService.getCluster())
.map((res:Response) => res.json())
.catch(this._errorHandler);
  }


 }

I know my question is long and confusing. I would appreciate any help.

Answer 1

您需要在生命周期挂钩OnDestroy中退订这两个组件。