WordCamp Lagos 2019 Tunbosun Ayinla Developing Your First WordPress Plugin

Tunbosun Ayinla Developer at Sandhills Development, LLC Lagos WordPress Meetup Group Co-organizer ABOUT ME

‣ What is a WordPress Plugin ‣ Hooks ‣ Actions ‣ Filters ‣ Let’s create a plugin ‣ Questions AGENDA

WHAT IS A WORDPRESS PLUGIN?

WHAT IS A WORDPRESS PLUGIN? ‣ Plugins are packages of code that extend the core functionality of WordPress. ‣ WordPress plugins are made up of PHP code and other assets such as images, CSS, and JavaScript. https://developer.wordpress.org/plugins/intro/what-is-a-plugin

PLUGIN HEADER At the top of every main plugin file is the plugin header comment. This is what tells WordPress that this is a plugin.

PLUGIN HEADER SAMPLE

HOOKS

HOOKS? WordPress hooks allow you to tap into WordPress at specific points to change how WordPress behaves without editing any core files. A hook allows you to add your own code or change what WordPress is doing or outputting by default. ‣ Actions ‣ Filters WordPress has two types of Hooks.

ACTIONS

WHAT ARE ACTIONS? Actions allows you to add data or change how WordPress operate. An action is always triggered at a specific time when WordPress is running.

‣ $hook ‣ $function_to_add ‣ $priority ‣ $accepted_args HOW TO HOOK INTO AN ACTION?

‣ $hook - the action you want to hook into when it is run ‣ $function_to_add - the callback function which will be called when the action is run ‣ $priority - (int) the priority given to the callback function ‣ $accepted_args - (int) the number of arguments that will be passed to the callback function HOW TO HOOK INTO AN ACTION?

AN EXAMPLE OF AN ACTION

FILTERS

Filters allow you to get and modify WordPress data before is is sent to the database or the browser. A filter allows you to modify content before it is displayed to the user. WHAT ARE FILTERS?

‣ $tag ‣ $function_to_add ‣ $priority ‣ $accepted_args HOW TO HOOK INTO A FILTER?

‣ $tag - the filter you want to target when it is run ‣ $function_to_add - the callback function which will be called when the filter is run ‣ $priority - (int) the priority given to the callback function ‣ $accepted_args - (int) the number of arguments that will be passed to the callback function HOW TO HOOK INTO A FILTER?

AN EXAMPLE OF A FILTER

‣ A plugin can be a single file but it is always recommended to create a directory to hold your plugin file ‣ Always prefix your function names ‣ Sanitize all input data ‣ Enable debug mode when developing a plugin
 define( 'WP_DEBUG', true ); IMPORTANT NOTES

RESOURCES

RESOURCES WordPress Plugin Handbook https://developer.wordpress.org/plugins WordPress Code Reference https://developer.wordpress.org/reference WordPress Coding Standards https://make.wordpress.org/core/handbook/best-practices/coding-standards/ WordPress TV http://wordpress.tv/?s=plugins

QUESTIONS?

https://bosun.me @tubiz Thank You