Angular 2 Tutorial: Adding HotKeys (Keyboard shortcuts) to a Component

Arguably hotkeys can substantially increase the usability of an application, the less the users have to touch the mouse the better will be their experience with the application.

Luckily for us there is a very easy way of defining hotkeys on angular2, which is by adding a listener to the host component, we can accomplish this by just adding the element host to the @Component decorator.

Let’s take a look at an example:

import {Component } from '@angular/core';
 
@Component({
  selector: 'hotkeys-app',
  host: {'(window:keydown)': 'hotkeys($event)'},
  template: `
  	<button (click)=showMessage()>Hotkey Test</button>
  `,
})
export class AppComponent { 
 
   hotkeys(event){
      if (event.keyCode == 65){
         this.showMessage();
      }
   }
 
   showMessage(){
      alert('Hotkey Test');
   }
}

As you can see I’ve used the element host to add a listener to the window:keydown event, it will call the function hotkeys(event) every time this event occurs, all we have to do now on this function is to determine which key was pressed and take actions accordingly.

As an example I’ve placed a button on the template, let’s suppose we want the action of this button, which is the showMessage() funtion, to execute when the user presses the letter 'a' on the keyboard. On the hotkeys function we have the event parameter containing the keyCode, we have to check this value to see which key was pressed, in this case I’m calling showMessage() when the keycode is 65 (which is code for the letter 'a').

It’s also very common to use combinations as hotkeys, like for example ctrl+a. To do that we just have to change our condition a little bit:

if (event.keyCode == 65 && event.ctrlKey){

The only diference is that besides checking the keyCode I’m also using the event.ctrlKey to check if the ctrl key is pressed.

That’s it guys! Just leave a comment if you have any doubts.

Recommended for you

Login Screen and Authentication with Angular2 Angular2 Login Screen Before we start I just want to say that in order to easily understand this tutorial you should already have some basic knowledge about Angular 2, it will involve routing, dependency injection and working with multiple components. I don't want to make this tutorial too long,...
Angular2: Uncaught (in promise): Error: Cannot match any routes: ” If you're specifying the routes on your project for the first time you may see the following error on the console when you run it: core.umd.js:3462 EXCEPTION: Uncaught (in promise): Error: Cannot match any routes: ''ErrorHandler.handleError @ core.umd.js:3462next @ core.umd.js:6924schedulerFn @...
Angular2 Tutorial: Creating Attribute Directives According to Angular2 documentation, directives are classes that can change the component behavior or/and appearance, which basically means they can add CSS classes and styles, register events and manipulate the component's properties. In this tutorial I'm going to show you how to create a very ...
Angular2 Forms Tutorial: Validating Required Fields Angular2 Form Validation In this tutorial I'll give you a simple example of how to validate a form with angular2. As you can see in the image, the example consists of a form with two required fields, the form can only be submitted if both fields are valid. I'm going to use bootstrap for styli...

3 comments on “Angular 2 Tutorial: Adding HotKeys (Keyboard shortcuts) to a Component

Leave a Reply

Your email address will not be published. Required fields are marked *

Obs: Use the tag <pre lang="LANGUAGE"> to include code blocks to your comment.
Example: <pre lang="javascript"> console.log('Test'); </pre>