shared-service.ts
import { Observable } from 'rxjs/Observable';
import { Injectable } from '@angular/core';
import { Subject } from 'rxjs/Subject';
@Injectable()
export class SharedService {
// Observable string sources
private emitChangeSource = new Subject<any>();
// Observable string streams
changeEmitted$ = this.emitChangeSource.asObservable();
// Service message commands
emitChange(change: any) {
this.emitChangeSource.next(change);
}
}
Now inject the instance of the above service in the constructor of both the parent and child component.
The child component will be emitting a change every time the onClick() method is called
child.component.ts
import { Component} from '@angular/core';
@Component({
templateUrl: 'child.html',
styleUrls: ['child.scss']
})
export class ChildComponent {
constructor(
private _sharedService: SharedService
) { }
onClick(){
this._sharedService.emitChange('Data from child');
}
}
The parent component shall receive that change. To do so,capture the subscription inside the parent's constructor.
parent.component.ts
import { Component} from '@angular/core';
@Component({
templateUrl: 'parent.html',
styleUrls: ['parent.scss']
})
export class ParentComponent {
constructor(
private _sharedService: SharedService
) {
_sharedService.changeEmitted$.subscribe(
text => {
console.log(text);
});
}
}
Hope this helps :)