Book Image

JavaScript and JSON Essentials

By : Sai S Sriparasa
Book Image

JavaScript and JSON Essentials

By: Sai S Sriparasa

Overview of this book

The exchange of data over the Internet has been carried out since its inception. Delimiter-separated lists such as CSV and tag-separated languages such as XML are very popular, yet they are considered to be verbose by a section of developers. JSON (JavaScript Object Notation) is a lightweight text-based code to create objects to transfer data over the Internet. It is a data exchange format that is human-readable (like XML, but without the markup around your actual payload) and its syntax is a subset of the JavaScript language that was standardized in 1999. JavaScript and JSON Essentials is a step-by-step guide that will introduce you to JSON and help you understand how the lightweight JSON data format can be used in different ways either to store data locally or to transfer data over the Internet. This book will teach you how to use JSON effectively with JavaScript. This book begins with a brief refresher course on JavaScript before taking you through how JSON data can be transferred via synchronous, asynchronous, and cross-domain asynchronous HTTP calls. JSON is not just about data transfer; this book throws light on the alternate implementations of JSON as well. You will learn the data types that JavaScript uses and how those data types can be used in JSON. You will go through the concepts of how to create, update, parse, and delete a JSON object. You will also look at the different techniques of loading a JSON file onto a web page, how to use jQuery to traverse through an object, and how to perform access operations. You will also go over a few resources that will make debugging JSON quick and easy.
Table of Contents (15 chapters)

Hosting JSON

In this section, we will be creating a PHP script that will allow us to send a JSON feedback to the user upon a successful request. Let's take a look at the index.php file, which accomplishes this task:

In this PHP script, we have created a basic students array and are generating the JSON feed for that array. The students array contains basic student information, such as the first name, last name, student ID, and the classes that the student has enrolled.

This file has to be placed in the www folder, and it should be on the same level as the default index.html file that comes with the LAMP installation. Refer to the folder structure in the following screenshot:

Now that our index.php is in the document root folder, we can load this file using our web server. To access this file via our Apache web server, navigate to http://localhost/index.php.

As shown in the preceding screenshot, when the file is run using the Apache web server, the server takes the request, parses the PHP code...