Put users with the selected role in demo mode.

ConditionalDemo.module

<?php

/**
 * Conditional Demo for ProcessWire
 * 
 * author: Martijn Geerts
 * 30 august 2013
 *
 * ProcessWire 2.x 
 * Copyright (C) 2012 by Ryan Cramer 
 * Licensed under GNU/GPL v2, see LICENSE.TXT
 * 
 * http://www.processwire.com
 * http://www.ryancramer.com
 *
 */

class ConditionalDemo extends WireData implements Module, ConfigurableModule {

  public static function getModuleInfo() {
		return array(
			'title' => __('Conditional Demo', __FILE__), // getModuleInfo title
			'summary' => __('Put ProcessWire in demo mode for users with the selected role(s)', __FILE__), // getModuleInfo summary
			'version' => 1, 
			'singular' => true, 
			'autoload' => true, 
			); 
	}
    
    
    /**
     * Array containing (int) id's from selected roles
     *
     */    
	protected static $defaults = array(
		"roles" => null,
		);
	
	
	/**
	 * Populate default config data
	 *
	 */
	public function __construct() {
		foreach(self::$defaults as $key => $value) $this->set($key, $value); 
	}


	/**
	 * Initialize the hook
	 *
	 */
	public function init() {
		$this->addHookBefore('Page::render', $this, 'setDemoMode'); 
	}	
	
	
	/**
	 * Put user in demo id user has selected role(s) 
	 *
	 */
	public function setDemoMode($event) {
		// Array containing selected role(s) id's
		$demo_roles = (array) $this->roles; 
		
		foreach($this->user->roles as $role) {
			if( in_array($role->id, $demo_roles)) {
				$this->config->demo = true;
				break;
			}
		}		
	}
	
	
	/**
	 * Module interactive configuration field
	 *
	 */
	static public function getModuleConfigInputfields(array $data) {
 
		$config = wire("config");
		// Array with (int) ID's from Guest & Superuser roles
		$exclude = array( $config->guestUserRolePageID, $config->superUserRolePageID );

		$data = array_merge(self::$defaults, $data);

		$fieldwrapper = new InputfieldWrapper();
		$field = wire("modules")->get('InputfieldAsmSelect');
		$field->name = 'roles';
		$field->value = $data['roles'];
		$field->label = __('Select Roles');
		$field->description = __('Put ProcessWire in demo mode for users with the selected role(s)');
		foreach(wire('roles') as $role) {
		    // exclude Guest & Superuser roles
			if(!in_array($role->id, $exclude)) {
				$field->addOption($role->id, $role->name);
			}
		}
		$fieldwrapper->append($field);
		return $fieldwrapper;
	}	 
}