JavaScriptExamples

A collection of useful JavaScript snippets that go over major concepts in Node.js (and a little bit broader). Currently includes concepts such as:

• Promise/Async
• AJAX
• Fetch

Documentation

Documentation for each of the example scripts described below can be located in the docs/ folder under their names (i.e. fetch.js has its documentation in the docs/fetch folder.

Examples

There are some scripts that are invoked via an HTML file (specifically the ones using AJAX/Fetch). The corresponding HTML file is the same name as its script. For example, there is a ajax.html an a corresponding ajax.js. The ajax.js script is invoked using the ajax.html file. All other scripts, such as PromiseAsyncAwait.js are invoked using node. Below are the specifics to each file:

ajax

Asynchronous JavaScript and XML (AJAX) runs by sending requests to a server. For this example, the server clueService.js (see below) must be running in order to receive the AJAX request and return JSON packages. Once the server is running, simply open the ajax.html file and the JavaScript file will be invoked upon load.

clueService.js

This script is an Express server (specific to node) that listens off port 8088 with a wildcard CORS policy (meaning it can accept traffic from any request) and returns JSON packages depending on the specified endpoint. This server is used for both ajax and fetch.

fetch

Same exact example as ajax except it utilizes fetch, a more popular method of retrieving JSON data as AJAX is slowly being phased out. Compare the 2 side-by-side to see the difference.

FetchWeather

Uses fetch to retrieve weather information from Apixu weather service about 5 major cities. Information on each can be retrieved by selecting its name from the drop down. Note that for this example, you must enter your own key in order for the request to work. You can do so by setting the value of the APIXU_KEY constant located at the top. To get a key, register on the website.

PromiseAsyncAwait

This displays the functionality of Promises and their use on async/await function methods. It shows 2 methods of invoking and using a Promise to block IO on the event queue.