Send asynchronous browser requests with fetch, XMLHttpRequest, JSON, errors, and progressive UI.
Lessons
See how AJAX changed the web from full reloads to live updates.
History of AJAX is easiest to learn by reading the example, changing it, and observing the result.
async function loadLessons() {
const response = await fetch('/api/lessons', {
headers: { 'Accept': 'application/json' }
});
if (!response.ok) {
throw new Error(`HTTP ${response.status}`);
}
return response.json();
}
loadLessons()
.then(lessons => console.log(lessons))
.catch(error => console.error('Failed to load:', error.message));Practice the History of AJAX example in a small scratch file, then explain what changed and why.