Managing Events in Angular 2 and Creating Custom Event Handlers

Question

Managing Events in Angular 2 and Creating Custom Event Handlers

Currently, I am in the process of developing a component library in Angular 2 for our app teams to utilize. One of the components I recently created is a modal, but I am encountering some accessibility challenges. Specifically, I want the modal to close when the user presses the ESC key, unless there is an internal component like a dropdown that should handle the ESC event instead. The flexible structure of the modal, which allows different content to be displayed using <ng-content>, creates additional complexity because I cannot predict what will be inside the modal.

Ideally, I would like to find a way to check if a projected component is listening for (keydown) or (keyup) events, or better yet, determine if another component has already handled the event. If this were an application I was building instead of providing a library, I could add attributes to the events within the projected components or create a custom event handler as discussed here. Unfortunately, those options are not available to me in this context.

javascript events angular typescript modal-dialog

Answer 1

Answer №1

Have you considered utilizing RxJS? Here is an example of how you can use it in your component:

isModalVisible: boolean = false;
private keyup$ = Observable.fromEvent(document, "keyup");
private keyupSubscription: any;

ngOnInit() {
    this.keyupSubscription = this.keyup$.subscribe((e: KeyboardEvent) => {
        if(this.isModalVisible && e.keyCode === 27) {
             this.isModalVisible = false;
        }
    });
}

ngOnDestroy() {
    this.keyupSubscription.unsubscribe();
}

onShowModal() {
    this.isModalVisible = true;
}

In your template, you can then include the following code:

...
<button (click)="onShowModal($event)">Show Modal</button>
...
<your-modal *ngIf="isModalVisible"></your-modal>
...

Answer 2

Have you considered utilizing RxJS? Here is an example of how you can use it in your component:

isModalVisible: boolean = false;
private keyup$ = Observable.fromEvent(document, "keyup");
private keyupSubscription: any;

ngOnInit() {
    this.keyupSubscription = this.keyup$.subscribe((e: KeyboardEvent) => {
        if(this.isModalVisible && e.keyCode === 27) {
             this.isModalVisible = false;
        }
    });
}

ngOnDestroy() {
    this.keyupSubscription.unsubscribe();
}

onShowModal() {
    this.isModalVisible = true;
}

In your template, you can then include the following code:

...
<button (click)="onShowModal($event)">Show Modal</button>
...
<your-modal *ngIf="isModalVisible"></your-modal>
...

Managing Events in Angular 2 and Creating Custom Event Handlers

Answer №1

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