Sarah Clark, Program Manager, Google Developer Training
Front-end web developers face challenges when using common “asynchronous” requests. These requests, such as fetching a URL or reading a file, often lead to complicated code, especially when performing multiple actions in a row. How can we make this easier for developers?
Javascript Promises
are a new tool that simplifies asynchronous code, converting a tangle of callbacks and event
handlers into simple, straightforward code such as:
fetch(url).then(decodeJSON).then(addToPage)...
Promises are used by many new web standards, including Service Worker, the Fetch API, Quota Management, Font Load Events,Web MIDI, and Streams.
We’ve just opened up a online course on Promises, built in collaboration with Udacity. This brief course, which you can finish in about a day, walks you through building an “Exoplanet Explorer” app that reads and displays live data using Promises. You’ll also learn to use the Fetch API and finally kiss XMLHttpRequest goodbye!
This short course is a prerequisite for most of the Senior Web Developer Nanodegree. Whether you are in the paid Nanodegree program or taking the course for free, won’t you come learn to make your code simpler and more reliable today?