Book Image

Learning WordPress REST API

By : Sufyan bin Uzayr, Mathew Rooney
Book Image

Learning WordPress REST API

By: Sufyan bin Uzayr, Mathew Rooney

Overview of this book

The WordPress REST API is a recent innovation that has the potential to unlock several new opportunities for WordPress developers. It can help you integrate with technologies outside of WordPress, as well as offer great flexibility when developing themes and plugins for WordPress. As such, the REST API can make developers’ lives easier. The book begins by covering the basics of the REST API and how it can be used along with WordPress. Learn how the REST API interacts with WordPress, allowing you to copy posts and modify post metadata. Move on to get an understanding of taxonomies and user roles are in WordPress and how to use them with the WordPress REST API. Next, find out how to edit and process forms with AJAX and how to create custom routes and functions. You will create a fully-functional single page web app using a WordPress site and the REST API. Lastly, you will see how to deal with the REST API in future versions and will use it to interact it with third-party services. By the end of the book, you will be able to work with the WordPress REST API to build web applications.
Table of Contents (16 chapters)
Learning WordPress REST API
About the Authors
About the Reviewer

Getting started with REST implementation

We are now familiar with REST API and JSON. Plus, we also know that REST API is indeed useful in many different ways. Let us now try to put it into practice.

Passing commands in SOAP versus REST

Say, we need to query a given database for user details of a user with ID 1191. Using web services and Simple Object Access Protocol (SOAP), we will be doing something such as the following:

<?xml version="1.1"?> 
<soap:body pb=""> 

The preceding code will give us an embedded XML file inside a SOAP response envelope.

And how will we do this using REST? The following way:

Yes, that is all. It is a simple URL with GET request, and the response will give us the raw data, that is, the details of the user with ID 1191. While in SOAP, we needed multiple libraries to parse the response, in REST, we just need to pass the simple URL. We can even test the API directly right within the browser as a simple request.

Of course, the preceding example is a simplified case, and if need be, REST libraries do exist. However, as it becomes clear, REST is way simpler than web services and other counterparts.


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Handling data in REST

For complex operations, the methodology remains similar. Let us refine the preceding query and look for the user with first name Sample and last name User as follows:

As we can see, for longer parameters, we are including the parameters within the body of the HTTP POST request. At this point, it is useful to discuss REST requests in themselves.

For simpler queries of a read-only nature, GET is the de facto standard. However, for read-only queries that are complex in nature, POST requests can be used. Of course, POST requests are also used for queries that can change the state of the data and deal with creation, updating, and deletion of data.

If you are wondering how to distinguish a simple query from a complex one, consider this: when reading a blog, you send a GET request as a simple query to open the page, but if you decide to post a comment on the blog post or share it via any of the social networks, you send a POST request with additional and more complex details.

And in terms of server responses, RESTful services can handle XML, CSV, and JSON. Each of these formats has its own advantages: XML, for example, is pretty easy to expand, CSV is compact and lightweight, whereas JSON is easy to parse. As you might have guessed by now, for WordPress REST API, JSON is the way to go, all thanks to JavaScript.


Unless the response needs to be read by humans, HTML is not the de facto choice for REST server responses. Of course, since almost everything on the World Wide Web needs to be read by humans, HTML is being used as a server response for RESTful services.