How to detect click outside of an element in Angul

问题:

This div will be dynamically shown on the page as an east panel when the open panel button is clicked. The bool showEastPanel variable is what is used to open and close the east panel. I am trying to use (clickoutside) to close the panel (setting showEastPanel to false) however the open panel runs first on the Angular hook and the panel is set to true then false and the panel doesn't display. Is the any way to scope `clickoutside' to not include the button?

<div [ngClass]="{'d-none': !showEastPanel, 'east-panel-container': showEastPanel}" (clickOutside)="ClosePanel()">
<div id="east-panel">
  <ng-template #eastPanel></ng-template>
</div>

<button (click)="ShowPanel()">Open Panel</button>

回答1:

Here is the link to the working demo: Stackblitz Demo

I would do this by using the Angular recommended approach which is also easy to develop apps in environments with no DOM access, I mean Renderer 2 class which is an abstraction provided by Angular in the form of a service that allows manipulating elements of your app without having to touch the DOM directly.

In this approach, you need to inject Renderer2 into your component constructor, which the Renderer2 lets us to listen to triggered events elegantly. It just takes the element you're going to listen on as the first argument which can be window, document, body or any other element reference. For the second argument it takes the event we're going to listen on which in this case is click, and the third argument is actually the callback function which we do it by arrow function.

this.renderer.listen('window', 'click',(e:Event)=>{ // your code here})

The rest of the solution is easy, you just need to set a boolean flag which keeps the status of the menu (or panel) visibility, and what we should do is to assign false to that flag when it's clicked outside of the menu.

HTML

<button #toggleButton (click)="toggleMenu()"> Toggle Menu</button>

<div class="menu" *ngIf="isMenuOpen" #menu>
I'm the menu. Click outside to close me
</div>

app.component.ts

export class AppComponent {
  /**
   * This is the toogle button elemenbt, look at HTML and see its defination
   */
  @ViewChild('toggleButton') toggleButton: ElementRef;
  @ViewChild('menu') menu: ElementRef;

  constructor(private renderer: Renderer2) {
    /**
     * This events get called by all clicks on the page
     */
    this.renderer.listen('window', 'click',(e:Event)=>{
         /**
          * Only run when toggleButton is not clicked
          * If we don't check this, all clicks (even on the toggle button) gets into this
          * section which in the result we might never see the menu open!
          * And the menu itself is checked here, and it's where we check just outside of
          * the menu and button the condition abbove must close the menu
          */
        if(e.target !== this.toggleButton.nativeElement && e.target!==this.menu.nativeElement){
            this.isMenuOpen=false;
        }
    });
  }

  isMenuOpen = false;

  toggleMenu() {
    this.isMenuOpen = !this.isMenuOpen;
  }
}

Again, if you like to see the working demo, use this link: Stackblitz Demo

回答2:

you can do something like this

  @HostListener('document:mousedown', ['$event'])
  onGlobalClick(event): void {
     if (!this.elementRef.nativeElement.contains(event.target)) {
        // clicked outside => close dropdown list
     this.isOpen = false;
     }
  }

and use *ngIf=isOpen for the panel

回答3:

Here's a reusable directive, it also cover the case if the element is inside an ngIf:

import { Directive, ElementRef, Optional, Inject, Output, EventEmitter, OnInit, OnDestroy } from '@angular/core';
import { fromEvent, Subscription } from 'rxjs';
import { DOCUMENT } from '@angular/common';
import { filter } from 'rxjs/operators';

@Directive({
  selector: '[outsideClick]',
})
export class OutsideClickDirective implements OnInit, OnDestroy {
  @Output('outsideClick') outsideClick = new EventEmitter<MouseEvent>();

  private subscription: Subscription;

  constructor(private element: ElementRef, @Optional() @Inject(DOCUMENT) private document: any) {}

  ngOnInit() {
    setTimeout(() => {
      this.subscription = fromEvent<MouseEvent>(this.document, 'click')
        .pipe(
          filter(event => {
            const clickTarget = event.target as HTMLElement;
            return !this.isOrContainsClickTarget(this.element.nativeElement, clickTarget);
          }),
        )
        .subscribe(event => this.outsideClick.emit());
    }, 0);
  }

  private isOrContainsClickTarget(element: HTMLElement, clickTarget: HTMLElement) {
    return element == clickTarget || element.contains(clickTarget);
  }

  ngOnDestroy() {
    if (this.subscription) this.subscription.unsubscribe();
  }
}

Credits to https://github.com/ngez/platform, I got most of the logic out of it.

What I was missing was the setTimeout(..., 0), which makes sure to schedule the check after the component using the directive has been rendered.

Useful links:

• https://stackoverflow.com/a/779785/5869296
• https://github.com/ngez/platform

回答4:

I would like to add the solution that helped me to achieve proper result.

When using embedded elements and you want to detect click on parent, event.target gives reference to the basic child.

HTML

<div #toggleButton (click)="toggleMenu()">
    <b>Toggle Menu</b>
    <span class="some-icon"></span>
</div>

<div #menu class="menu" *ngIf="isMenuOpen">
    <h1>I'm the menu.</h1>
    <div>
        I have some complex content containing multiple children.
        <i>Click outside to close me</i>
    </div>
</div>

I click on "Toggle menu" text, event.target returns reference to 'u' element instead of #toggleButton div.

For this case I used M98's solution including Renderer2, but changed the condition to the one from Sujay's answer.

ToggleButton.nativeElement.contains(e.target) returns true even if the target of click event is in nativeElement's children, which solves the problem.

component.ts

export class AppComponent {
/**
 * This is the toogle button element, look at HTML and see its definition
 */
    @ViewChild('toggleButton') toggleButton: ElementRef;
    @ViewChild('menu') menu: ElementRef;
    isMenuOpen = false;

    constructor(private renderer: Renderer2) {
    /**
     * This events get called by all clicks on the page
     */
        this.renderer.listen('window', 'click',(e:Event)=>{
            /**
             * Only run when toggleButton is not clicked
             * If we don't check this, all clicks (even on the toggle button) gets into this
             * section which in the result we might never see the menu open!
             * And the menu itself is checked here, and it's where we check just outside of
             * the menu and button the condition abbove must close the menu
             */
            if(!this.toggleButton.nativeElement.contains(e.target) && !this.menu.nativeElement.contains(e.target)) {
                this.isMenuOpen=false;
            }
        });
    }

    toggleMenu() {
        this.isMenuOpen = !this.isMenuOpen;
    }
}

回答5:

I have did the same in one of my requirement to show mega menu popup when user clicks on menu icon but want to close it whet user clicks outside it. Here i am trying to prevent click on icon as well. Please have a look.

In HTML

 <div #menuIcon (click)="onMenuClick()">
  <a><i class="fa fa-reorder"></i></a>
 </div>
<div #menuPopup  *ngIf="showContainer">
   <!-- Something in the popup like menu -->
</div>

In TS

  @ViewChild('menuIcon', { read: ElementRef, static: false })  menuIcon: ElementRef;
  @ViewChild('menuPopup', { read: ElementRef, static: false })  menuPopup: ElementRef;
   showContainer = false;

      constructor(private renderer2: Renderer2) {
      this.renderer2.listen('window', 'click', (e: Event) => {
        if (
         (this.menuPopup && this.menuPopup.nativeElement.contains(e.target)) ||
          (this.menuIcon && this.menuIcon.nativeElement.contains(e.target))
         ) {
              // Clicked inside plus preventing click on icon
             this.showContainer = true;
           } else {
             // Clicked outside
             this.showContainer = false;
         }
      });
    }

     onMenuClick() {
        this.isShowMegaMenu = true;
      }