Exchange references between two same-level components

Question

I have two custom-components that are spawned by a common parent with different data as two tabs on mat-tab-group.

<mat-tab-group>
  <mat-tab label="TAB1">
    <ng-template matTabContent>
      <custom-component [data]="tab1data"></custom-component>
    </ng-template>
  </mat-tab>
  <mat-tab label="TAB2">
    <ng-template matTabContent>
      <custom-component [data]="tab2data"></custom-component>
    </ng-template>
  </mat-tab>
</mat-tab-group>

The data is a setter that sets the internal _data and wraps it in MatTableDataSource:

@Input()
set data(val: Data[]) {
    this._data = val;
    this.loadData();
}

loadData(): void {
    this.dataSource = new MatTableDataSource<Data>(this._data);
    this.dataSource.sort = this.sort;
}

I have a situation where actions for component on the first tab should affect data on the other tab. Is there any way to pass component references, so I could change _data and call loadData() from other component?

Answer 1

You can do this with Rxjs observables

Here is stackblitz example of how to communicate between two components https://stackblitz.com/edit/angular-ivy-myr2kh

my-service.service.ts

import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';

@Injectable()
export class MyServiceService {
  private dataChangeObservable = new Subject<any>();
    dataChangeStream = this.dataChangeObservable.asObservable();

  constructor() { }

  emitDataChange() {
    this.dataChangeObservable.next();
  }
}

ComponentOne.component.ts

onclickDiv() {
    this.myService.emitDataChange(); // Here you are triggering for change
}

ComponentTwo.component.ts

ngOnInit() {
    this.dataChangeSubscription$ = this.myService.dataChangeStream.subscribe(() => {
       this.count++; // Here you will get notified/listener of change
    })
 }

Update

If you have same component instances, then you have to pass some value to determine on which instance should get updated

Like

https://stackblitz.com/edit/angular-ivy-4pznor

Your parent html

<app-componentone [name]="'one'"></app-componentone>
<app-componentone [name]="'two'"></app-componentone>

Here one and two pass as an input to just to identify the instance

Then your ts

import { Component, OnInit, Input } from '@angular/core';
import { MyServiceService } from '../my-service.service';

@Component({
   selector: 'app-componentone',
   templateUrl: './componentone.component.html',
   styleUrls: ['./componentone.component.css']
})
export class ComponentoneComponent implements OnInit {
  @Input() name; // it will have instance name
  count = 0;
  constructor(
     private myService: MyServiceService
  ) { }

  ngOnInit() {
    this.myService.dataChangeStream.subscribe((value) => { // here we will get to notify which instance should get updated
      if (this.name !== value) { // Here we checking for instance name for updating, if same component instance don't do anything else update
         this.count++;
      }
    })
  }

  onclickDiv() {
    // Here I am passing parameter, so if click is triggered from instance one, we have to update other instances, so passing parameter 'one' i.e. name, to avoid updating same component instance

    this.myService.emitDataChange(this.name);
  }
}