NgxResizeObserver

Angular 21.x library to monitor changes to elements. Uses ResizeObserver to do the work.

If you would like to simply know when elements are visible, check out ngx-visibility.

If you want to be notified when DOM elements change properties, ngx-mutation-observer would be a good pick.

Demonstration

There's a live demo over at CodeSandbox.io.

Installation

Install like other Angular libraries. First run a command to download the module.

npm install ngx-resize-observer

Next, add the module to your project.

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';

// Import the module
import { NgxResizeObserverModule } from 'ngx-resize-observer';

import { AppComponent } from './app.component';

@NgModule({
declarations: [AppComponent, ItemComponent],

// Include the module.
imports: [BrowserModule, FormsModule, NgxResizeObserverModule],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule {}

Finally, you leverage the service directly or use some directives for common uses.