function myplugin_widget_init()
{
    // Register myplugin_widget::display() and myplugin_widget::control()
}

function myplugin_widget_display()
{
    // Echo content
}

function myplugin_widget_control()
{
    // Echo administration control
}

http://funcdoc.wordpress.com/2008/02/04/writing-wordpress-widget-best-practices/

Widget Best Practice: Using Functions

php, plugin, wordpress, best

PHP