In this lab we will explore promise chaining in Angular, using $q and $http requests.

Your goal is build a user-friendly dashboard that can fetch and display the raw JSON for any given API endpoint.

A random delay of up to 900ms is in place on all $http request!

Clone this repo.

Install the budo development server:

npm install budo -g

To run the server, make sure you're inside the application directory, then run:

budo --open

The homepage is broken. Your goal is to get the dasboard API interface working!

You may code in:

• js/api_dashboard_controller.js
• index.html

User Interface Improvements:

• Can you clear the input field
• Can you submit on enter?
• Don't make me wait for API calls!
  • Display a load spinner so that I know the app still works:
    • See styles/main.css for a custom glyphicon-spin style.
    • Add this line to see the spinner: <span class="glyphicon glyphicon-refresh glyphicon-spin"></span>
• Avoid the "flicker". Make sure the user never literally sees {{ ... }} or placeholder data rendered anywhere in the html.

In js/app.js you can modify the FAIL_RATE constant to simulate, for example, a 50% chance that your $http requests will fail / be rejected by the server.

FAIL_RATE: 50 // 50% percent chance requests will fail

Take advantage of the random failures/delays to create a seamless user experience. How can you signal the following application states to your user:

• The request was sent to the server
• We're waiting for a response (e.g. display a load spinner)
• The request was successful (the server responded with a 2xx status code and data).
• The request was not successful (the server responded with a 4xx or 5xx status code and an error message).

• Javascript Callstack & Event Loop [Video]
• Promises in Javascript
• Promises in jQuery
  • jQuery.Deferred
  • deferred object
• Promises in Angular
  • $q
• Angular $http module reference