Getting Started with WordPress Plugin Development

Writing plugins for WordPress may seem like a daunting task if you’re new to WordPress. But all it takes is a good starting point to get the ball rolling.

First, you will need to make the appropriate directories and files. In your /wp-content/plugins/ directory, make a new folder with your desired plugin name, and a .php file with the same name.

Open up the .php with your favorite editor and add some basic plugin info into the file header:

<?php
/**
 * Plugin Name: Auto Image Plugin
 * Description: Automatically adds an image to every post.
 * Version: 1.0
 * Author: SpinSpire
 * Author URI: http://www.spinspire.com
 */

Add a filter function:

function auto_add_image( $content ) {
  return $content . '<p><img src="YOUR IMG URL HERE"></p>';
}

add_filter('the_content','auto_add_image', 1);

This will call add_filter where the first value is the hook name “the_content” and the second being your function name “auto_add_image”. Save and enable the plugin under WordPress Plugins settings.

Make sure to read up on http://developer.wordpress.org/ and the WordPress Codex for more documentation.