Host Binding Migration

Recent Angular releases recommend using the host property instead of the @HostBinding and @HostListener decorators, as these decorators are retained primarily for backward compatibility. This schematic will assist you in migrating your code to utilize the new host property.

How it works?

The moment you run the schematics, it will look for all the decorators that have binding and replace them with host properties.

• It will keep the same name for the attributes and properties bindings.
• It will update the component’s decorators by adding the host property if it does not exist or by adding additional properties within it.
• It won’t convert properties to signals.
• It will remove the @HostListener, @HostBinding decorators.

Example

Before running the schematics:

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

@Component({
  /* ... */
})
export class CustomSlider {
  @HostBinding('attr.aria-valuenow')
  value: number = 0;

  @HostBinding('tabIndex')
  getTabIndex() {
    return this.disabled ? -1 : 0;
  }

  @HostListener('keydown', ['$event'])
  updateValue(event: KeyboardEvent) {
    /* ... */
  }
}

After running the schematics:

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

@Component({
  host: {
    '[attr.aria-valuenow]': 'value',
    '[tabIndex]': 'disabled ? -1 : 0',
    '(keydown)': 'updateValue($event)',
  },
})
export class CustomSlider {
  value: number = 0;
  disabled: boolean = false;
  updateValue(event: KeyboardEvent) {
    /* ... */
  }
}

Usage

In order to run the schematics for all the project in the app you have to run the following script:

ng g ngxtension:convert-host-binding

If you want to specify the project name you can pass the --project param.

ng g ngxtension:convert-host-binding --project=<project-name>

If you want to run the schematic for a specific component or directive you can pass the --path param.

ng g ngxtension:convert-host-binding --path=<path-to-ts-file>

Usage with Nx

To use the schematics on a Nx monorepo you just swap ng with nx

Example:

nx g ngxtension:convert-host-binding --project=<project-name>