Book Image

WordPress Plugin Development Cookbook - Third Edition

By : Yannick Lefebvre
Book Image

WordPress Plugin Development Cookbook - Third Edition

By: Yannick Lefebvre

Overview of this book

WordPress is one of the most widely used, powerful, and open content management systems (CMSs). Whether you're a site owner trying to find the right extension, a developer who wants to contribute to the community, or a website developer working to fulfill a client's needs, learning how to extend WordPress' capabilities will help you to unleash its full potential. This book will help you become familiar with API functions to create secure plugins with easy-to-use administration interfaces. This third edition contains new recipes and up-to-date code samples, including new chapters on creating custom blocks for the block editor and integrating data from external sources. From one chapter to the next, you’ll learn how to create plugins of varying complexity, ranging from a few lines of code to complex extensions that provide intricate new capabilities. You'll start by using the basic mechanisms provided in WordPress to create plugins, followed by recipes covering how to design administration panels, enhance the post editor with custom fields, store custom data, and even create custom blocks. You'll safely incorporate dynamic elements into web pages using scripting languages, learn how to integrate data from external sources, and build new widgets that users will be able to add to WordPress sidebars and widget areas. By the end of this book, you will be able to create WordPress plugins to perform any task you can imagine.
Table of Contents (15 chapters)

Displaying RSS items from an external feed

RSS is a technology that has been around since the early days of the internet. Its main purpose is to allow users to be easily notified when new content is published on their favorite sites. The underlying mechanism behind RSS feeds is a simple XML file that contains the site's headlines along with updated timestamps and part or all of the content of new items that are posted. Applications or services called RSS aggregators (for example, Feedly and NewsBlur) can monitor the content of RSS feeds and display new items as they are published or notify users of this new content. It is interesting to note that podcasts use the same RSS feed technology to publish their episodes online.

While RSS is not as popular as it used to be, most news-based websites still publish RSS feeds. WordPress includes a copy of the SimplePie library to allow developers to easily fetch and cache RSS feed data and easily display it on a site.

Getting ready