JavaScript Promises

We expect that students have built web apps in the past and they are familiar with the pitfalls of callback-heavy code. There is no HTML or CSS in this class.

JavaScript Skills Required:

• Using functions to return objects and other functions
• Basic understanding of scope and closures
• Reading and writing named and anonymous callbacks
• Array methods like .forEach and .map

Other Requirements:

• Ability to use GitHub to clone repos and checkout branches
• Comfort with command line tools

See the Technology Requirements for using Udacity.

Projects

Project 2: Public Transportation App

You will build an application that allows users to select a departure and arrival train station, and see a list of trains, times, and durations. A default train schedule will be provided that should be used when the application is offline. If a network connection exists, the application will query an endpoint that provides information about all arrival and departure times.

Lesson 1 - Creating Promises

• Why Promises?
• Promises syntax and scope
• Simplifying common, useful methods with Promises
• Basic error handling

Lesson 2 - Chaining Promises

• Creating sequences of async work manually
• Advanced error handling
• Techniques for generating sequences of async work with array methods

Project

Throughout the course (mostly in the second lesson), you'll be using Promises to load data into the Exoplanet Explorer app, which was designed to help people learn a little bit about planets around other stars.