#lazy-loading code explainers

typescript

import { Component, signal } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RevenueChartComponent } from './revenue-chart.component';
import { ReportService, RevenueReport } from './report.service';

Deferred chart loading with @defer in Angular

lazy-loading signals dependency-injection

Intermediate 8 steps

typescript

import { Injectable, inject } from '@angular/core';
import { PreloadingStrategy, Route } from '@angular/router';
import { Observable, of, Subject } from 'rxjs';
import { filter, switchMap, take } from 'rxjs/operators';

A hover-triggered preloading strategy in Angular

lazy-loading rxjs preloading

Advanced 8 steps

typescript

type LazyImageOptions = {
  rootMargin?: string;
  loadedClass?: string;
};

Lazy-loading images with IntersectionObserver

intersectionobserver lazy-loading performance

Intermediate 7 steps

javascript

import { lazy, Suspense } from "react";
import { Routes, Route, NavLink } from "react-router-dom";
import ErrorBoundary from "./components/ErrorBoundary";
import Spinner from "./components/Spinner";

Lazy-loaded routes in React

code-splitting lazy-loading routing

Intermediate 6 steps

typescript

import { Injectable } from '@angular/core';
import { PreloadingStrategy, Route, Routes, RouterModule } from '@angular/router';
import { NgModule } from '@angular/core';
import { Observable, of, timer } from 'rxjs';

A custom preloading strategy in Angular

lazy-loading preloading rxjs

Intermediate 7 steps

typescript

import { inject } from '@angular/core';
import { ResolveFn, Router, ActivatedRouteSnapshot } from '@angular/router';
import { catchError, of, EMPTY } from 'rxjs';
import { Article } from './models/article';

Prefetching route data with an Angular resolver

route-resolver dependency-injection rxjs

Intermediate 6 steps

javascript

function initLazyLoad(root = document) {
  const images = root.querySelectorAll('img[data-src]');
 
  if (!('IntersectionObserver' in window)) {

How lazy image loading works

lazy-loading intersectionobserver progressive-enhancement

Intermediate 8 steps