Still having some trouble, OOP is still new to me. I am trying to call a Class method from outside my main plugin class. My get_user() call works fine inside of my “Main” class, but when trying to call it from outside, NULL is returned. Here is what I have done so far, I have included only the code I thought was relevant to the problem and have put comments where necessary.

<?php

class Main {
	
	protected $user = null;
	
	public function __construct() {
		
		// Init and admin init action hooks
		
	}
	
	public function init() {
		
		// Check for piklist plugin
		// Enqeue admin styles and scripts
		// Action hook on authenticate function

	}
	
	public function authenticate() {
		
		$this->set_user( "John Smith" );

	}
	
	public function set_user( $new_user ) {
		$this->user = $new_user;
	}
	
	public function get_user() {
		return $this->user;
	}
	
}

/* ------------------------------------------------
 * Code from /parts/settings/twitter.php
 * ------------------------------------------------*/
 
	$instance = Main::get_instance();
	$user = $instance->get_user();
	
	var_dump ( $user );

	// Hidden field gets the username and registers it as a setting in the database
	piklist('field', array(
		'type' => 'hidden'
		,'field' => 'user_name'
		,'value' => $user
	));

?>