Here's a foundation for writing a WordPress plugin, based on version 3.2. This would go in the main my-plugin-name.php file.
/**
* Plugin Name: Plugin Name
* Plugin URI: http://authorname.com/plugin/
* Description: Description of Plugin
* Author: Author Name
* Version: 1.0
* Author URI: http://www.authorname.com
*/
/**
* Copyright 2011 Author Name
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
define('MYPLUGIN_VERSION', '1.0');
define('MYPLUGIN_PLUGIN_URL', plugin_dir_url( __FILE__ ));
/* for plugin Settings in Admin */
function myplugin_admin() {
include('myplugin-admin.php');
}
add_action('init', 'myplugin_init');
add_action('plugins_loaded', 'myplugin_do_something');
add_action('admin_menu', 'myplugin_admin_actions');
add_action('update_option_mypluginoption', 'myplugin_do_something_else');
function myplugin_admin_actions() {
// add_options_page('My Plugin Options', 'My Plugin', 'manage_options', 'my-unique-identifier', 'my_plugin_options');
add_options_page("My Plugin", "My Plugin", "manage_options", "My Plugin", "myplugin_admin");
}
function potd_init() {
if (is_admin()) {
wp_register_script('myplugin.js', MYPLUGIN_PLUGIN_URL . 'myplugin.js', array('jquery'));
wp_enqueue_script('myplugin.js');
}
}
function myplugin_install() {
global $wpdb;
// Create default options if needed
add_option('myplugin_option', 'the option');
// Create a table if necessary (only if can't use options or postmeta tables)
$table_name = $wpdb->prefix . "myplugin";
// Create myplugin table if not existing
if ($wpdb->get_var("SHOW TABLES LIKE '$table_name'") != $table_name) {
$sql = "
CREATE TABLE IF NOT EXISTS `" . $table_name . "` (
`id` BIGINT(20) NOT NULL AUTO_INCREMENT PRIMARY KEY,
`field_one` VARCHAR(255) NOT NULL
);";
require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
dbDelta($sql);
// Initial insert
$rows_affected = $wpdb->insert(
$table_name,
array(
'field_one' => 'a string'
)
);
}
}
function myplugin_do_something() {
// something to do when plugins are loaded
}
function myplugin_do_something_else() {
// do something when options are updated
}
/**
* Replaces shortcode "[myplugin]" with plugin stuff
* Can be called anywhere in template with
* <?php echo do_shortcode('[myplugin]'); ?>
* @param array $atts
* @param string $content
* @param string $code
*/
function myplugin_shortcode($atts = array(), $content=null, $code="") {
// have to return, not echo
return 'something to replace shortcode';
}
/**
* Drops the table and deletes the options
* when user clicks "delete plugin"
*/
function potd_uninstall() {
global $wpdb;
$table_name = $wpdb->prefix . "myplugin";
if ($wpdb->get_var("SHOW TABLES LIKE '$table_name'") === $table_name) {
$qry = "
DROP TABLE `{$table_name}`
";
$wpdb->query($qry);
}
delete_option('myplugin_option');
}
register_activation_hook( __FILE__, 'myplugin_install' );
add_shortcode( 'myplugin', 'myplugin_shortcode' );
register_uninstall_hook( __FILE__, 'myplugin_uninstall' );
