CODEWITHSUNDEEP
angularangular7angular-material-6
Mohit Harshan
Mohit Harshan

Reputation: 1986

Behaviour Subject Sidenav Toggle Angular 7 Material

Im using angular material and i have placed the sidenav toggle button in the navbar. I am trying to subscribe to a boolean value to toggle the sidenav.The boolean is to be passed to one of the child components.

My service :

 import { Injectable } from '@angular/core';
import {BehaviorSubject, Observable} from 'rxjs'


@Injectable()
export class SidenavService {
    private sidenav$ : BehaviorSubject<boolean>;

    constructor() {
        this.sidenav$ = new BehaviorSubject<boolean>(false);
    }
    getData():Observable<boolean> {
        return this.sidenav$.asObservable();
    }

    updateData(data: boolean) {
        this.sidenav$.next(data);
        console.log("Changed toggle",data);

    }
}

Im updating the service in the navbar component like:

  sidenavtoggle(){
    this.toggleSidenav.emit();
    this.isOpen = !this.isOpen;
    console.log("IS OPEN",this.isOpen);
    this.sidenavService.updateData(this.isOpen);

    };
  }

I have injected the service and gave it in the providers for the component. Im subscribing to the observable in the child component sidebar component like:

  constructor(private sidenavService:SidenavService) {
    this.prepareNavItems();

    this.subsciption=this.sidenavService.getData().subscribe(data=>{
      console.log("RECEIVED DATA",data);
      this.isExpanded=data;
    });

  }

The problem is that the data is subscribed only once when the component is loaded,and not changing when the boolean value is changed.HOw do i continuosly listen to changes in the boolean when updateData() is called?

HTML : 

<mat-nav-list  >

  <div class="side-bar-btn" [ngClass]="{'is-active': toggle}" (click)="clickEvent($event)">
    <div class="side-bar-btn-box">
      <div class="side-bar-btn-inner"></div>
    </div>
  </div>

  <mat-list-item *ngFor="let navItem of navItems" routerLinkActive="sidebarlinkactive" routerLink="{{navItem.link}}" >
    <a routerLinkActive="active">
      <mat-icon mat-list-icon>{{navItem.icon}}</mat-icon>
      <div matLine *ngIf="isExpanded">{{navItem.text}}</div>
    </a>
  </mat-list-item>

</mat-nav-list>

Upvotes: 2

Views: 2097

Answers (1)

Sheik Althaf
Sheik Althaf

Reputation: 1605

try to use async pipe and also i have modified to your code some

import { Injectable } from '@angular/core';
import {BehaviorSubject, Observable} from 'rxjs'


@Injectable()
export class SidenavService {
    private sidenavSource$ = new BehaviorSubject<boolean>(false);
    sidenav$ = this.sidenavSource$.asObservable();

    updateData(data: boolean) {
        this.sidenavSource$.next(data);
        console.log("Changed toggle",data);

    }
}

In your HTML use async pipe

constructor(public sidenavService: SidenavService) {} //make the service public

<div matLine *ngIf="sidenavService.sidenav$ | async">{{navItem.text}}</div>

<button (click)="sidenavService.updateData(true)">open</button>
<button (click)="sidenavService.updateData(false)">close</button>

Upvotes: 3

Related Questions