两个非相关组件之间的角度数据共享

Question

I am trying to share data between two non related components using service and observable concept but its giving issue. I have a drop down component and when ever the drop down value changes it needs to update the side nav bar component once the value of drop down is received. For this purpose I have simply defined a LOB service which has set and get methods. From DROP DOWN COMPONENT on change method if called in which I am calling set method of LOB Service. While on ngOnInit inside the Side Nav Component I am calling the get component. But i am not receiving the value also getting the error. Here is my code:

  1.drop down component: 
onChange(event): void {  
    const newVal = event.target.value;
    this.PreSelectedDropDown=newVal;
    this.lobService.SetLOB(newVal); //service set method called
  
}

 2. Side bar component : //Subscribing to observable in ngOninit()
    this.lobService.GetLOB.subscribe(valData =>{
       this.dropDownSelected=valData;
       console.log(this.dropDownSelected + " -- inside side nav getting value");
       this.createNavList();//Calling create nav when ever new drop down value comes up so component is recreated.

   });



3. Service for data sharing bw two components: 
   export class LobmenuService {

     data:string="";
     constructor() { }

     private getLOB: BehaviorSubject<any> = new BehaviorSubject<any>(null);

     GetLOB: Observable<any> = this.getLOB.asObservable();

     setLOB(plan: any) {
         this.getLOB.next(plan);
    }
 }

Looking forward to help as I am unable to get value as it gives error unable to read property 'includes' of undefined. So how to update component and whether to do subscribe on ngOnit or not. Thanks

Answer 1

   2. Side bar component : //Subscribing to observable in ngOninit()
    this.lobService.GetLOB.subscribe(valData =>{
       this.dropDownSelected=valData;
       console.log(this.dropDownSelected + " -- inside side nav getting value");
       this.createNavList();//Calling create nav when ever new drop down value comes up so component is recreated.
   });

move the above code to the constructor and check once this might help you.