ngx-zero-dialog

A lightweight, zero-dependency Angular library for managing dialogs using the native HTML <dialog> API. Accessible, customizable, and fully driven by CSS animations.

Requires Angular 16 or newer

Live Demo

Quick Start

Install the library:

npm install ngx-zero-dialog
# or
yarn add ngx-zero-dialog

Add a dialog container to your root component template (e.g. app.component.html):

<div id="ngx-zero-dialog-container"></div>

Provide the configuration in your app config:

import { provideNgxZeroDialog } from 'ngx-zero-dialog';

export const appConfig: ApplicationConfig = {
  providers: [
    provideNgxZeroDialog({ containerNodeID: 'ngx-zero-dialog-container' }),
  ],
};

Import the library styles in your global stylesheet:

@import "ngx-zero-dialog/styles/ngx-zero-dialog.scss";

Open a dialog:

import { NgxZeroDialogService } from 'ngx-zero-dialog';

@Component({ ... })
export class MyComponent {
  private readonly dialog = inject(NgxZeroDialogService);

  open(template: TemplateRef<unknown>) {
    this.dialog.openDialog(template).subscribe((result) => {
      console.log('Dialog closed with:', result);
    });
  }
}

<button (click)="open(myDialog)">Open</button>

<ng-template #myDialog let-dialogRef>
  <p>Hello from a dialog!</p>
  <button (click)="dialogRef.close('done')">Close</button>
</ng-template>

That's it — no custom host component needed. A built-in default host with a close button is used automatically.

NgModule setup: If you're not using standalone APIs, add provideNgxZeroDialog(...) to your module's providers array instead.

---

Core Concepts

Three-Element Dialog Structure

Each dialog consists of three elements:

1. Native <dialog> element — created automatically, provides browser-level modal behavior (focus trapping, backdrop, stacking context)
2. Host component — the dialog's frame/chrome (title bar, close button, layout). A built-in default is provided, or you can create your own.
3. Content — your actual dialog body, passed as a Component or TemplateRef

Stacking Context

HTML dialogs exist in their own top-layer, ensuring that dialogs and their child views never intersect regardless of z-index or how nodes are positioned. No overlay system or CDK is needed.

Observable-Based API

openDialog() returns a cold Observable — the dialog is only created when subscribed to. The observable emits a single result value when the dialog closes, then completes.

---

API Reference

NgxZeroDialogService

The main service. Has one public method:

openDialog<Result>(
  componentOrTemplate: Component | TemplateRef<any>,
  config?: IDialogConfig,
): Observable<DialogResult<Result>>

IDialogConfig

All fields are optional:

interface IDialogConfig {
  /** Close when clicking outside the dialog. Default: true */
  closeOnBackdropClick?: boolean;

  /** Close when pressing Escape. Default: true */
  closeOnEsc?: boolean;

  /**
   * Host component wrapping the dialog content.
   * If omitted, a built-in DefaultDialogHostComponent is used.
   */
  hostComponent?: Component;

  /** Data injected into the host component via HOST_DATA token */
  hostData?: IHostData;

  /** CSS class(es) added to the native <dialog> element */
  dialogNodeClass?: string | string[];

  /** Data injected into the content via DIALOG_DATA token */
  dialogData?: IDialogData;

  /** Enable open/close CSS transitions. Default: true */
  animated?: boolean;
}

DialogRef<Result>

A reference to an open dialog, available in both host and content components via the DIALOG_REF token.

class DialogRef<Result = unknown> {
  /** The underlying native <dialog> element */
  readonly nativeDialog: HTMLDialogElement;

  /** Observable that emits the result when the dialog closes */
  readonly closed$: Observable<DialogResult<Result>>;

  /** Close the dialog, optionally emitting a result value */
  close(value?: DialogResult<Result>): void;

  /**
   * Register a guard that is called before close.
   * Return false (or Observable<false> / Promise<false>) to prevent closing.
   */
  beforeClose(guard: BeforeCloseGuard<Result>): void;
}

DialogResult<Result> is Result | undefined — undefined is emitted when the dialog closes without a value.

BeforeCloseGuard

type BeforeCloseGuard<Result> = (
  value?: DialogResult<Result>
) => boolean | Observable<boolean> | Promise<boolean>;

Example — confirm before closing:

@Component({ ... })
export class MyDialog {
  private readonly dialogRef = inject<DialogRef<string>>(DIALOG_REF);

  constructor() {
    this.dialogRef.beforeClose(() => confirm('Discard changes?'));
  }
}

Injection Tokens

Token	Available in	Value
DIALOG_REF	Host + Content	DialogRef instance
DIALOG_DATA	Content	The dialogData object from config
DIALOG_CONFIG	Host	The full IDialogConfig
HOST_DATA	Host	The hostData object from config

---

Default Host vs. Custom Host

Default Host

When you omit hostComponent from the config, a built-in DefaultDialogHostComponent is used. It provides a minimal wrapper with a close button. Good for simple use cases.

Custom Host

For a consistent dialog frame across your app (title bar, footer, custom styling), create your own host:

1. Extend NgxZeroDialogHost<T> where T is the type of your hostData
2. Import DialogContentDirective and place <ng-template dialogContent></ng-template> in your template
3. Call super() in the constructor

interface MyHostData {
  title: string;
}

@Component({
  standalone: true,
  selector: 'app-dialog-host',
  imports: [DialogContentDirective],
  template: `
    <div class="header">
      <h2>{{ hostData.title }}</h2>
      <button (click)="close()">&times;</button>
    </div>
    <div class="body">
      <ng-template dialogContent></ng-template>
    </div>
  `,
})
export class AppDialogHostComponent extends NgxZeroDialogHost<MyHostData> {
  constructor() {
    super();
  }

  close() {
    this.dialogRef.close();
  }
}

Use it:

this.dialog.openDialog(MyContentComponent, {
  hostComponent: AppDialogHostComponent,
  hostData: { title: 'Settings' },
}).subscribe();

NgxZeroDialogHost automatically injects dialogRef, dialogConfig, and hostData for you. It also handles backdrop-click and Escape key behavior based on the config.

---

Animations

ngx-zero-dialog uses CSS class toggling for enter/leave animations. Two classes are applied to the <dialog> element:

• ngx-zero-dialog-hidden — applied on creation (before open transition)
• ngx-zero-dialog-visible — added after showModal() (triggers open), removed on close (triggers close)

The built-in styles provide a simple opacity fade:

dialog.ngx-zero-dialog-hidden {
  opacity: 0;
  transition: opacity 0.2s ease-in-out;

  &::backdrop {
    opacity: 0;
    transition: opacity 0.2s ease-in-out;
  }
}

dialog.ngx-zero-dialog-visible {
  opacity: 1;
  transition: opacity 0.2s ease-in-out;

  &::backdrop {
    opacity: 1;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(5px);
    transition: opacity 0.2s ease-in-out;
  }
}

Override these in your global styles for custom animations (e.g. slide-in):

dialog.ngx-zero-dialog-hidden {
  transform: translateY(100vh);
}

dialog.ngx-zero-dialog-visible {
  transform: translateY(0);
}

Disable animations globally via provideNgxZeroDialog({ ..., enableAnimations: false }) or per-dialog with animated: false in the config.

---

Global Configuration

interface INgxZeroDialogConfig {
  /** ID of the container element where dialogs are appended. Required. */
  containerNodeID: string;

  /** Globally enable/disable animations. Default: true */
  enableAnimations?: boolean;
}

---

License

MIT

Contributing

Feel free to open discussions, raise issues, or submit pull requests on GitHub.