adamwjo/js-server-communication

AJAX, Promises, and Fetch (Communicating with APIs)

• What is AJAX? Async JavaScript and XML
• What is blocking (sync) vs non-blocking code (async)?

How do we handle async code?

• For example, event listeners
• So what would server communication look like since it's async?
• https://www.reddit.com/.json

Callback Hell

• Nested callbacks within nested callbacks
• Triangle shape
• Really hard to read and manage

Welcome Fetch

• Built in web api
• Get JSON data
• Returns a promise object
• Practice with: https://animal-farm-api.herokuapp.com/animals

Promises and what are they

• MDN documentation
• Practice with: http://localhost:300/hello/1
• pending
• fulfilled (resolved/rejected)
• How to unwrap a promise using .then
• At Flatiron, we will work with promises via Fetch rather than creating our own Promises

Promise chaining

• .then().then()
• Easier to read, easier to manage

Reminder:

• First FSPs this Friday
• Even if you're not in the first group, start it asap, talk to the coaches