[javascript] Angular 2 Hover event

In the new Angular2 framework, does anyone know the proper way to do a hover like an event?

In Angular1 there was ng-Mouseover, but that doesn't seem to have been carried over.

I've looked through the docs and haven't found anything.

This question is related to javascript angular events hover

The answer is


If you are interested in the mouse entering or leaving one of your components you can use the @HostListener decorator:

import { Component, HostListener, OnInit } from '@angular/core';

@Component({
  selector: 'my-component',
  templateUrl: './my-component.html',
  styleUrls: ['./my-component.scss']
})
export class MyComponent implements OnInit {

  @HostListener('mouseenter') 
  onMouseEnter() {
    this.highlight('yellow');
  }

  @HostListener('mouseleave') 
  onMouseLeave() {
    this.highlight(null);
  }

...

}

As explained in the link in @Brandon comment to OP (https://angular.io/docs/ts/latest/guide/attribute-directives.html)


You can do it with a host:

import { Directive, ElementRef, Input } from '@angular/core';

@Directive({
  selector: '[myHighlight]',
  host: {
    '(mouseenter)': 'onMouseEnter()',
    '(mouseleave)': 'onMouseLeave()'
  }
})
export class HighlightDirective {
  private _defaultColor = 'blue';
  private el: HTMLElement;

  constructor(el: ElementRef) { this.el = el.nativeElement; }

  @Input('myHighlight') highlightColor: string;

  onMouseEnter() { this.highlight(this.highlightColor || this._defaultColor); }
  onMouseLeave() { this.highlight(null); }

   private highlight(color:string) {
    this.el.style.backgroundColor = color;
  }

}

Just adapt it to your code (found at: https://angular.io/docs/ts/latest/guide/attribute-directives.html )


For handling the event on overing, you can try something like this (it works for me):

In the Html template:

<div (mouseenter)="onHovering($event)" (mouseleave)="onUnovering($event)">
  <img src="../../../contents/ctm-icons/alarm.svg" class="centering-me" alt="Alerts" />
</div>

In the angular component:

    onHovering(eventObject) {
    console.log("AlertsBtnComponent.onHovering:");
    var regExp = new RegExp(".svg" + "$");

    var srcObj = eventObject.target.offsetParent.children["0"];
    if (srcObj.tagName == "IMG") {
        srcObj.setAttribute("src", srcObj.getAttribute("src").replace(regExp, "_h.svg"));       
    }

   }
   onUnovering(eventObject) {
    console.log("AlertsBtnComponent.onUnovering:");
    var regExp = new RegExp("_h.svg" + "$");

    var srcObj = eventObject.target.offsetParent.children["0"];
    if (srcObj.tagName == "IMG") {
        srcObj.setAttribute("src", srcObj.getAttribute("src").replace(regExp, ".svg"));
    }
}

If the mouse over for all over the component is your option, you can directly is @hostListener to handle the events to perform the mouse over al below.

  import {HostListener} from '@angular/core';

  @HostListener('mouseenter') onMouseEnter() {
    this.hover = true;
    this.elementRef.nativeElement.addClass = 'edit';
  }

  @HostListener('mouseleave') onMouseLeave() {
    this.hover = false;
    this.elementRef.nativeElement.addClass = 'un-edit';
  }

Its available in @angular/core. I tested it in angular 4.x.x


@Component({
    selector: 'drag-drop',
    template: `
        <h1>Drag 'n Drop</h1>
        <div #container 
             class="container"
             (mousemove)="onMouseMove( container)">
            <div #draggable 
                 class="draggable"
                 (mousedown)="onMouseButton( container)"
                 (mouseup)="onMouseButton( container)">
            </div>
        </div>`,

})

http://lishman.io/angular-2-event-binding


yes there is on-mouseover in angular2 instead of ng-Mouseover like in angular 1.x so you have to write this :-

<div on-mouseover='over()' style="height:100px; width:100px; background:#e2e2e2">hello mouseover</div>

over(){
    console.log("Mouseover called");
  }

As @Gunter Suggested in comment there is alternate of on-mouseover we can use this too. Some people prefer the on- prefix alternative, known as the canonical form.

Update

HTML Code -

<div (mouseover)='over()' (mouseout)='out()' style="height:100px; width:100px; background:#e2e2e2">hello mouseover</div>

Controller/.TS Code -

import { Component } from '@angular/core';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular';

  over(){
    console.log("Mouseover called");
  }

  out(){
    console.log("Mouseout called");
  }
}

Working Example

Some other Mouse events can be used in Angular -

(mouseenter)="myMethod()"
(mousedown)="myMethod()"
(mouseup)="myMethod()"

In your js/ts file for the html that will be hovered

@Output() elemHovered: EventEmitter<any> = new EventEmitter<any>();
onHoverEnter(): void {
    this.elemHovered.emit([`The button was entered!`,this.event]);
}

onHoverLeave(): void {
    this.elemHovered.emit([`The button was left!`,this.event])
}

In your HTML that will be hovered

 (mouseenter) = "onHoverEnter()" (mouseleave)="onHoverLeave()"

In your js/ts file that will receive info of the hovering

elemHoveredCatch(d): void {
    console.log(d)
}

In your HTML element that is connected with catching js/ts file

(elemHovered) = "elemHoveredCatch($event)"

Simply do (mouseenter) attribute in Angular2+...

In your HTML do:

<div (mouseenter)="mouseHover($event)">Hover!</div> 

and in your component do:

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'component',
  templateUrl: './component.html',
  styleUrls: ['./component.scss']
})

export class MyComponent implements OnInit {

  mouseHover(e) {
    console.log('hovered', e);
  }
} 

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