Question

I write that code

<?php
/**
* @package ppa
* @version 0.1
*/
/*
Plugin Name: PPAPlugin
Description: PPAPlugin desct
Author: Sekhmet
Version: 0.1
*/

    register_activation_hook( plugin_basename( __FILE__ ), array( 'PPA', 'activate' ) );
    register_deactivation_hook( plugin_basename( __FILE__ ), array( 'PPA', 'deactivate' ) );
    register_uninstall_hook( plugin_basename( __FILE__ ), array( 'PPA', 'uninstall' ) );


    class PPA
    {
        const NAME = "PPA";

        public static function activate() {
        self :: ppa_add_dashboard();
        }

        public static function deactivate() {
        }

        public static function uinstall() {
        }

        function ppa_add_dashboard() {
            wp_add_dashboard_widget( 'ppa_widget', self :: NAME , array($this, 'ppa_dashboard_widget') );
        }

        function ppa_dashboard_widget() {
        }
    }


?>

But when I trying enable it on ACP i get that messange:

Fatal error: Call to undefined function wp_add_dashboard_widget() in
/home/muffinki/domains/muffinki.org/public_html/wp-content/plugins/ppa/ppa.php
on line 35

WordPress version 3.5.1(latest).

Answer 1

Hook your ppa_add_dashboard() function into the wp_dashboard_setup action so it’s called at the correct time.

public static function activate() {
    add_action( 'wp_dashboard_setup', array( __CLASS__, 'ppa_add_dashboard' ) );
}

References:

http://codex.wordpress.org/Function_Reference/wp_add_dashboard_widget

http://codex.wordpress.org/Dashboard_Widgets_API