Working with AJAX
What Is AJAX?
Section titled “What Is AJAX?”AJAX (Asynchronous JavaScript and XML) is a web development technique that allows web applications to send and retrieve data from a server asynchronously without reloading the entire page. Only the relevant parts of the page are updated, making interactions faster and smoother.
AJAX is not a programming language but a concept that combines several technologies: JavaScript, the Fetch API ↗ (or the older XMLHttpRequest ↗), HTML/CSS, and data exchange formats like JSON.
How AJAX Works
Section titled “How AJAX Works”- Triggering event: The user interacts with the page (clicking a button, typing in a search field, scrolling, etc.).
- AJAX request: JavaScript sends an HTTP request to the server asynchronously using the Fetch API.
- Server processing: The server processes the request and sends back a response (typically JSON).
- Page update: JavaScript receives the response and updates the relevant part of the page via DOM manipulation.
Example — search without page reload:
- You type a search query and click “Search.”
- JavaScript sends the search term to the server via AJAX.
- The server returns results in JSON format.
- JavaScript updates the page to display the results — no reload needed.
Common Use Cases
Section titled “Common Use Cases”- Live search: Search suggestions that appear as you type.
- Form validation: Real-time checking (email availability, password strength).
- Chat applications: Sending and receiving messages without page refresh.
- Social media feeds: Infinite scrolling and live-updating content.
- Real-time dashboards: Weather apps, maps, and live data displays.