Unable to catch events from EventEmitter in Angular2?

DaylightProgrammer picture DaylightProgrammer · Jun 24, 2015 · Viewed 21.6k times · Source

I have written a basic angular application that utilises the EventEmitter class, however i cannot get the listening component to catch the event.

Here is my code (using alpha.27 on Angular2 / TypeScript 1.5 compiling to ES5) Apologises for the verbose example.

Any advice on what i am incorrectly doing what would be greatly appreciated.

import {Component, View, EventEmitter} from 'angular2/angular2';

@Component({
    selector: 'login',
    events : ['loggedIn']
})

@View({
    template: '<button type="button" (click)="submitForm()">Click Me</button>'
})

export class Login {

    loggedIn = new EventEmitter();

    constructor() { 
    }

    submitForm() {
        console.log("event fired");
        this.loggedIn.next({});
    }

}


@Component({
    selector: 'app'
})

@View({
    template: "<div>This is the application</div>"
})

export class App {
    constructor() {

    }
}

@Component({
  selector: 'root'
})

@View({
  template: '<app [hidden]=!showApp></app><login (loggedIn)="loggedIn()" [hidden]=showApp></login>',
  directives: [ App, Login ]
})

export class Root {

    showApp:boolean;

    constructor() { 
        this.showApp = false; 
    }

    loggedIn() { 
        console.log("event caught");
        this.showApp = true; 
    }

}

Answer

shmck picture shmck · Jun 28, 2015

Here is a working Plunker of your app.

import {Component, View, EventEmitter, bootstrap} from '@angular/core';

@Component({
   selector: 'login',
  events : ['update']
})
@View({
  template: '<button type="button" (click)="submitForm()">Login</button>'
})
class Login {
  constructor() { 
    this.update = new EventEmitter();
  }
  submitForm() {
    this.update.next();
  }
}


@Component({
  selector: 'app'
})
@View({
  template: "<div>This is the application</div>"
})
class App {}

@Component({
 selector: 'root'
})
@View({
  template: `
  <app [hidden]="!showApp"></app>
  <login (update)="loggedIn()" 
    [hidden]="showApp"></login>
  `,
  directives: [App, Login]
})
class Root {
    showApp:boolean;
    constructor() { 
        this.showApp = false; 
    }
    loggedIn() { 
        this.showApp = true; 
    }
}

bootstrap(Root);

I think there were a few problems. (update) in the template is a type of event, so it can't be called loggedIn. I found it easier just to call the event update altogether.