pattern examples

An_example.php

// example of how this would get called:
// during bootstrap:
// configuration specifies a "Messenger" resource with property enabled as true/false

class Bootstrap {
	protected function _initMessenger($config){
		Messenger_Root::init($config); // values from config are strings, hence the Saf_Filter_Truthy::filter call in ::init
	}
}

// ...
// also during boot strap, used to keep the numbers used in auto-generating sequence values lower

Saf_Ical::setBaseTime(Ems::getMinTimestamp());

// ...
// when sending a message with ical data

	Messenger_Root::get()->sendIcal($reservationCode, $username,
		'NCSU Libraries Room Reservation, [[$room]] for [[$date]] [[$year]]' ,
		'This message is to confirm your reservation for:
[[$location]]
at [[$userStart]] - [[$userEnd]]
on [[$date]] [[$year]]
If you need to modify or delete this reservation,
please return to the room reservation system:
[[$url]]
A calendar invitation is attached to this email, which you can add to your Google Calendar and share with others.
'
	);

Ems.php

/*
 * Encapsulates our business logic behind using the EMS System, Proxy and Facade to the API
 */
class Ems {
	public static function getBookingInfo($bookingId, $username)
	{
		$userId = self::getUserId($username); 
		$booking = self::$_api->getBooking($bookingId);
		if ($booking) {
			$filteredBookings = self::tidyBookings(array($bookingId => $booking));
			return $filteredBookings[$bookingId];
		} else {
			return NULL;
		}
	}
	
	public static function tidyBookings($bookings, $sortOrder = NULL)
	{
		foreach($bookings as $bookingId => $bookingData) {
			if (!array_key_exists('code', $bookings[$bookingId])) {//#NOTE try to avoid filtering twice
				$bookings[$bookingId]['code'] = "{$bookingData['reservationId']}/{$bookingId}";
				$bookings[$bookingId]['date'] = 
					Saf_Time::modify(
						strtotime($bookings[$bookingId]['date']),
						Saf_Time::MODIFIER_START_DAY
					);
				$bookings[$bookingId]['originalStart'] = $bookings[$bookingId]['start'];
				$bookings[$bookingId]['originalEnd'] = $bookings[$bookingId]['end'];
				$bookings[$bookingId]['dateString'] = 
					date(Ems::EMS_DATE_FORMAT, $bookings[$bookingId]['date']);
				$bookings[$bookingId]['userDate'] =
					date(Ems::EMS_USER_DATECALENDAR_FORMAT, $bookings[$bookingId]['date']);
				$bookings[$bookingId]['userYear'] =
					date('Y', $bookings[$bookingId]['date']);
				$bookings[$bookingId]['userMonth'] =
					date('M', $bookings[$bookingId]['date']);
				$bookings[$bookingId]['userDay'] =
					date('j', $bookings[$bookingId]['date']);
				$bookings[$bookingId]['startString'] =
					substr(
						$bookings[$bookingId]['start'], 
						strpos($bookings[$bookingId]['start'], 'T') + 1
					);
				$bookings[$bookingId]['fullStart'] =
					strtotime($bookings[$bookingId]['start']);
				$bookings[$bookingId]['userStart'] = date(
					Ems::EMS_USER_TIME_FORMAT, 
					$bookings[$bookingId]['fullStart']
				);
				$bookings[$bookingId]['start'] =
					Saf_Time::hourStringToStamp($bookings[$bookingId]['start']);
				$bookings[$bookingId]['endString'] =
					substr(
						$bookings[$bookingId]['end'], 
						strpos($bookings[$bookingId]['end'], 'T') + 1
					);
				$bookings[$bookingId]['fullEnd'] =
					strtotime($bookings[$bookingId]['end']);
				$bookings[$bookingId]['userEnd'] = date(
					Ems::EMS_USER_TIME_FORMAT, 
					$bookings[$bookingId]['fullEnd'] + 1
				);
				$bookings[$bookingId]['truncatedEnd'] =
					Saf_Time::hourStringToStamp($bookings[$bookingId]['end']);
				$bookings[$bookingId]['crossesMidnight'] =
					$bookings[$bookingId]['fullEnd'] - $bookings[$bookingId]['date']
						> Saf_Time::MAX_HOUR_STAMP;
				$bookings[$bookingId]['end'] =
					$bookings[$bookingId]['crossesMidnight']
					? $bookings[$bookingId]['truncatedEnd'] + Saf_Time::MAX_HOUR_STAMP + 1
					: $bookings[$bookingId]['truncatedEnd'];
				$bookings[$bookingId]['userEventType'] =
					self::getUserEventTypeLabel($bookings[$bookingId]['eventType']);
				$bookings[$bookingId]['userStatus'] =
					self::getUserStatusLabel($bookings[$bookingId]['status']);
				$bookings[$bookingId]['userRoom'] =
					self::getUserRoomLabel($bookings[$bookingId]['roomId']);
				$bookings[$bookingId]['userLocation'] =
					self::getUserLocationLabel($bookings[$bookingId]['roomId']);
				$bookings[$bookingId]['userFloor'] =
					self::getRoomDetails($bookings[$bookingId]['roomId'], 'floor');
				$bookings[$bookingId]['userBuilding'] =
					self::getUserBuildingLabel($bookings[$bookingId]['buildingId']);
				$bookings[$bookingId]['roomNumber'] =
					self::getRoomNumber($bookings[$bookingId]['roomId']);
				$bookings[$bookingId]['roomType'] =
					self::getRoomDetails($bookings[$bookingId]['roomId'], 'type');
				$bookings[$bookingId]['roomCapacity'] =
					self::getRoomDetails($bookings[$bookingId]['roomId'], 'capacity');
				$bookings[$bookingId]['userEmail'] = 'not loaded';
				$bookings[$bookingId]['userId'] = 'not loaded';
				$bookings[$bookingId]['userSortName'] = 'not loaded';
				$bookings[$bookingId]['username'] = 'not loaded';
				$bookings[$bookingId]['userLastname'] = 'not loaded';
				$bookings[$bookingId]['userFirstname'] = 'not loaded';
				$bookings[$bookingId]['userFullname'] = 'not loaded';
			}
		}
		return
			is_null($sortOrder)
			? $bookings
			: self::chronoSortBookings($bookings, $sortOrder);
	}
}

Ems_Api.php

/*
 * Implements interface to the EMS API and mediates requests to optimize performance between API calls and cache.
 */
class Ems_Api {
	public function getBooking($bookingId)
	{
		$params = array('bookingId' => $bookingId);
		$responseKeys = array(
			'date' => 'BookingDate',
			'start' => 'TimeEventStart',
			'end' => 'TimeEventEnd',
			'groupId' => 'GroupID',
			'description' => 'EventName',
			'reservationId' => 'ReservationID',
			'eventType' => 'EventTypeID',
			'status' => 'StatusID',
			'statusType' => 'StatusTypeID',
			'roomId' => 'RoomID',
			'buildingId' => 'BuildingID',
			'templateId' => 'WebProcessTemplateID'
		);
		return $this->_simpleSend('getBooking', $responseKeys, self::API_KEY_SINGLETON, $params);
	}
	
	private function _simpleSend($call, $keys = NULL, $idKey = self::API_KEY_DEFAULT, $params = NULL)
	{
		if (is_null($idKey)) {
			$idKey = self::API_KEY_DEFAULT;
		}
		$currentKey =
			$idKey === self::API_KEY_INTERATIVE
				|| $idKey === self::API_KEY_SINGLETON
			? 0
			: $idKey;
		$response = array();
		$message = new Saf_Message_Template($call);
		$messageParams = (is_null($params))? array(): $params;
		$messageParams['auth'] = $this->getAuthString();
		$dereferenceConfig = array(
			'params' => $messageParams
		);
		$dereferencedMessage = $message->get($dereferenceConfig);
		$rawResponse =  $this->send($dereferencedMessage);
		Saf_Profile::action('API', $call, array('size' => $rawResponse['length']));
		$finalPattern = 
			$idKey === self::API_KEY_SINGLETON
			? self::API_PARSE_PATTERN_SINGLETON
			: self::API_PARSE_PATTERN_NONE;
		$payload = $this->parseResponse($rawResponse, $finalPattern);
		if ($payload) {
			if ($finalPattern == self::API_PARSE_PATTERN_SINGLETON) {
				$payload  = array($payload);
			}
			foreach ($payload as $item) {
				if (
					(
						is_array($item) 
						|| !$keys
					) && (
						$idKey === self::API_KEY_SINGLETON
						|| $idKey === self::API_KEY_INTERATIVE
						|| array_key_exists($currentKey, $item) 
					)
				) {
					$itemKey = 
						$idKey === self::API_KEY_SINGLETON
							|| $idKey === self::API_KEY_INTERATIVE
						? $currentKey
						: $item[$currentKey];
					$response[$itemKey] = $keys ? array() : $item;
					if ($keys) {
						foreach($keys as $keyTransform => $key){
							$targetKey = is_numeric($keyTransform) ? $key : $keyTransform;
							$response[$itemKey][$targetKey] =
							array_key_exists($key, $item)
							? $item[$key]
							: NULL;
						}
					}
					if ($idKey === self::API_KEY_INTERATIVE) {
						$currentKey++;
					}
				}
			}
		}
		return 
			$finalPattern == self::API_PARSE_PATTERN_SINGLETON
			? (array_key_exists(0, $response) ? $response[0] : NULL)
			: $response;
	}
}

Event_Model.php

/*
 * Model object that knows how to generate a simple representation (memento) of an event
 */
class Event_Model {
	public static function get($identifier, $parameters = array())
	{
		$codeParts = explode('/',$identifier, 2);
		if ($codeParts && count($codeParts) == 2) {
			$bookingId = $codeParts[1];
			$username = 
				array_key_exists($parameters, $parameters)
				? $parameters['username']
				: NULL;
			$reservation = Ems::getBookingInfo($bookingId, $username);
			if (!$reservation) {
				throw new Ems_Exception_Reservation_404("Unable to load booking {$bookingId}");
			}
			$screened = Ems::screenBookings(
				array($bookingId => $reservation), 
				$username
			);
			$reservation = $screened[$bookingId];
		}
		return $reservation;
	}
}

Ical.php

/*
 * Class to build an iCal document from an map of data representing an event.
 * This is used for both generating e-mail attachments, and documents served as
 * a web service.
 */
class Saf_Ical {
	const METHOD_REQUEST = 'Request';
	const METHOD_PUBLISH = 'Publish';
	const METHOD_CANCEL = 'Cancel';
	const OUTPUT_COL_MAX = 70;
	const OUTPUT_ESCAPE_CHARS = ':;,\\';
	const OUTPUT_REMOVE_CHARS = "";
	const OUTPUT_DATESTAMP = 'Ymd\THis\Z';
	const AUTO_SEQUENCE = '*';
	const MIME_TYPE = 'text/calendar';
	protected $_ical = '';
	protected $_attachment = '';
	protected $_baseTime = NULL;
	protected $_timeInterval = 60;
	protected $_method = self::METHOD_REQUEST;
	protected $_id = NULL;
	protected $_filename = 'event.ics';
	
	protected $_hostId = '';
	protected $_productId = '';
	protected $_lang = 'EN';
	protected $_version = '2.0';
	protected static $_systemBaseTime = 0;
	
	protected static $_itemProps = array(
		'VEVENT' => array(
			'UID' => 1,
			'ORGANIZER' => '?',
			'ATTENDEE[]' => '*',
			'DTSTART' => 1,
			'DTEND' => 1,
			'DTSTAMP' => 1,
			'LOCATION' => '?',
			'SEQUENCE' => '?',
			'LAST-MODIFIED' => '?',
			'SUMMARY' => 1,
			'DESCRIPTION' => '?',
			'URL' => '?',
			'STATUS' => '?',
			'CATEGORIES' => '?'
		)
	);
	
	protected static $_propHelperMap = array(
		'fullStart' => 'DTSTART',
		'start' => 'DTSTART',
		'fullEnd' => 'DTEND',
		'end' => 'DTEND',
		'now' => 'DTSTAMP',
		'modified' => 'LAST-MODIFIED',
		'title' => 'SUMMARY',
		'sequence' => 'SEQUENCE',
		'name' => 'SUMMARY',
		'description' => 'SUMMARY',
		'userEmail' => 'ATTENDEE',
		'attendeeEmail' => 'ATTENDEE',
		'ownerEmail' => 'ORGANIZER',
		'userLocation' => 'LOCATION',
	);
	
	public function __construct($config = array())
	{
		$this->_hostId = Saf_Array::extract('hostId', $config, APPLICATION_ENV . '.' . APPLICATION_HOST);
		$this->_productId = Saf_Array::extract('productId', $config, APPLICATION_ID . '.' . APPLICATION_INSTANCE);
		$this->_baseTime = (int)Saf_Array::extract('baseTime', $config, self::$_systemBaseTime);
		$this->_timeInterval = (int)Saf_Array::extract('timeInterval', $config, $this->_timeInterval);
		$this->_method = Saf_Array::extractOptional('method', $config);
		$this->_id = Saf_Array::extractOptional('id', $config);
		switch ($this->_method) {
			case self::METHOD_REQUEST:
				$this->setMethodRequest();
				break;
			case self::METHOD_PUBLISH:
				$this->setMethodPublish();
				break;
			case self::METHOD_CANCEL:
				$this->setMethodCancel();
				break;
		}
		if (!is_null($this->_id) && (!is_array($this->_id) || count($this->_id) > 0)) {
			$this->generate($config);
		}
	}
	
	public function __toString()
	{
		return $this->getIcal();
	}
	public function setMethodRequest()
	{
		$this->_method = self::METHOD_REQUEST;
	}
	
	public function setMethodPublish()
	{
		$this->_method = self::METHOD_PUBLISH;
	}
	
	public function setMethodCancel()
	{
		$this->_method = self::METHOD_PUBLISH;
	}
	
	public function generate($data)
	{
		if(is_array($this->_id)) {
			$this->_generateMulti($data);
		} else {
			$this->_generate($data);
		}
	}
	
	public function getIcal()
	{
		return $this->_ical;
	}
	
	public function getAttachment()
	{
		return $this->_attachment;
	}
	
	protected function _getHeader()
	{
		$method = strtoupper($this->_method);
		$product = self::escapeText("{$this->_productId}//{$this->_hostId}");
		$url = '';
		return "BEGIN:VCALENDAR\n"
			. "METHOD:{$method}\n"
			. "PRODID:-//{$product}//{$this->_lang}\n"
			. "VERSION:{$this->_version}\n"
			. $url;
	}
	
	protected function _getFooter()
	{
		return "END:VCALENDAR";
	}
	protected function _generate($data, $id = NULL)
	{
		$type = 'VEVENT'; //#TODO #2.0.0 support other types
		$itemData = $data;
		$this->_ical =
			(is_null($id) ? $this->_getHeader() : '')
			. "BEGIN:{$type}\n"
			. $this->_renderItem($type, is_null($id) ? $this->_id : $id , $itemData)
			. "END:{$type}\n"
			. (is_null($id) ? $this->_getFooter() : '');
		$this->_generateAttachment();
	}
	
	protected function _generateMulti($data)
	{
		$items = array();
		foreach($this->_id as $id => $item) {
			$items[] = $this->_generate($item, $id);
		}
		$this->_ical =
		$this->_getHeader()
			. implode("\n", $items)
			. $this->_getFooter();
		$this->_generateAttachment();		
	}
	
	protected function _renderItem($type, $id, $data)
	{
		$out = '';
		$outType = strtolower(substr($type, 1));
		$outProp = "$prop:";
		$dateStamp = gmdate(self::OUTPUT_DATESTAMP, Saf_Time::time());
		$version = $this->getVersion($data);
		$atProps = 'CUTYPE=INDIVIDUAL;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE'; //or just ROLE=REQ-PARTICIPANT;
		$uid = "{$outType}{$id}@{$this->_hostId}";
		//#TODO #2.0.0 see what more advanced attendee properties we can support...
		foreach(self::$_itemProps[$type] as $prop => $card) {
			$value = NULL;
			$propKey = array_key_exists($prop, $data)
				? $prop
				: $this->_resolvePropKey($prop, $data);
			$outProp = "$prop:";
			switch ($prop){
				case 'ORGANIZER':
				case 'ATTENDEE': 
					$attendeeMail =
						$propKey
							&& array_key_exists($propKey, $data)
						? $data[$propKey]
						: NULL;
					$cnSource =
						array_key_exists('USER:CN', $data)
						? $data['USER:CN']
						: (
							array_key_exists('userFullname', $data)
							? $data['userFullname']
							: NULL
						);
					if (is_array($attendeeMail)) {
						foreach($attendeeMail as $email) {
							$outProp = array();
							if (
								is_array($cnSource) && array_key_exists($email, $cnSource)
							) {
								$cn = ";CN={$cnSource[$email]}";
							} else {
								$cn = '';
							}
							$outProp = 'ATTENDEE;';
							$value[] = "{$atProps}{$cn}:MAILTO:{$email}";
						}
					} else if (!is_null($attendeeMail)) {
						$attendeeCn =
							is_array($cnSource)
							? ''
							: ";CN={$cnSource}";
						$outProp = 'ATTENDEE;';
						$value = "{$atProps}{$attendeeCn}:MAILTO:{$attendeeMail}";
					}
					break;
				case 'DTSTAMP':
				case 'DTSTART':
				case 'DTEND':
				case 'LAST-MODIFIED':
					$value = 
						$propKey
							&& array_key_exists($propKey, $data)
						? $data[$propKey]
						: NULL;
					if (!is_null($value)) {
						if (Saf_Time::isTimeStamp($value)) {
							$value = gmdate(self::OUTPUT_DATESTAMP, $value);
						} else {
							//#TODO #2.0.0 detect non-GMT and convert
						}
					} else if ($prop == 'DTSTAMP') {
						$value = gmdate(self::OUTPUT_DATESTAMP, Saf_Time::time());
					}
					break;
					
				case 'UID':
					$value = $uid;
					break;
				case 'SEQUENCE':
					if (
						$propKey
						&& array_key_exists($propKey, $data)
						&& $data[$propKey] == '*'
					) {
						$value = Saf_Time::time() - $this->_baseTime;
					} else if (
						$propKey
						&& array_key_exists($propKey, $data)
					) {
						$value = (int)$data[$propKey];
					}
					break;
					
				case 'STATUS':
					switch (strtoupper($this->_method)) {
						case 'CANCEL' :
							$value = 
								$propKey
									&& array_key_exists($propKey, $data)
								? strtoupper($data[$propKey])
								: NULL;
							break;
						case 'PUBLISH' :
						case 'REQUEST' :
						default:
							$value = 
								$propKey
									&& array_key_exists($propKey, $data)
								? strtoupper($data[$propKey])
								: 'CONFIRMED';
					}
					break;
				default:
					if ($propKey && array_key_exists($propKey, $data)) {
						$value = self::escapeText($data[$propKey]);
					}
			}
			if ($card === '+' || $card === 1) {
				if (is_null($value)) {
					throw new Exception("Required value {$prop} missing to generate iCal for {$uid}");
				}
			} else if ($card === '?' || $card === 1) {
				if (is_array($value)) {
					throw new Exception("Too many values provided for {$prop} to generate iCal for {$uid}");
				}
			}
			if (is_array($value) && count($value) > 0) {
				foreach($value as $subValue) {
					$out .= "{$outProp}{$subValue}\n";
				}
			} else if (!is_array($value) && !is_null($value)) {
				$out .= "{$outProp}{$value}\n";
			}
		}
		return $out;
	}
	
	protected function _resolvePropKey($key, $data)
	{
		foreach(self::$_propHelperMap as $dataKey => $propKey){
			if (
				array_key_exists($dataKey, $data)
				&& self::$_propHelperMap[$dataKey] == $key
			) {
				return $dataKey;
			}
		}
		return NULL;
	}
	
	protected function _generateAttachment()
	{
		$this->_attachment = new Zend_Mime_Part($this->_ical);
		$method = strtoupper($this->_method);
		$this->_attachment->type = "text/calendar; method={$method}";
		$this->_attachment->disposition = Zend_Mime::DISPOSITION_INLINE;
		$this->_attachment->encoding = Zend_Mime::ENCODING_8BIT;
		$this->_attachment->filename = $this->_filename;
	}
	
	public static function escapeText($string)
	{
		$removeChars = str_split(self::OUTPUT_REMOVE_CHARS);
		$filtered = addcslashes(
			str_replace($removeChars, '', $string),	
			self::OUTPUT_ESCAPE_CHARS
		);
		$lines = str_split($filtered, self::OUTPUT_COL_MAX);
		if (strlen($lines[count($lines) - 1]) == 0) { //#TODO #2.0.0 research if this is needed
			unset($lines[count($lines) - 1]);
		}
		return implode("\n ", $lines);
	}
	
	public function getVersion()
	{
		return $this->_version;
	}
	public function getTimedVersion()
	{
		$versionTime = time() - $this->_baseTime;
		return (
			$versionTime - ($versionTime % $this->_timeInterval)
		) / $this->_timeInterval;
	}
	public static function setBaseTime($timestamp)
	{
		self::$_systemBaseTime = $timestamp;
	}
}

Messenger.php

/*
 * Mediator class that can create and handle different message types.
 */
class Messenger
{
	protected $_name = NULL;
	protected $_address = NULL;
	
	public __construct($config)
	{
		$name = 
			Saf_Array::keyExistsAndNotBlank('name', $config) 
			? trim($config['name'])
			: NULL;
		$this->setName($name);
		$address = 
			Saf_Array::keyExistsAndNotBlank('address', $config) 
			? trim($config['address'])
			: '';
		$this->setAddress($address);
	}
	
	public function setName($name)
	{
		if ($name) {
			$this->_name = $name;
			return TRUE;
		}
		return FALSE;
	
	public function setAddress($address)
	{
		if ($address && !Saf_Filter_Email::filter($config['address'])) {
			throw new Exception('Invalid Sender Address');
		} else if($address){
			$this->_address = $address;
			return TRUE;
		}
		return FALSE;
	}
	
	public static function sendIcal($event, $username, $subject, $message, $isUpdate = FALSE)
	{
		$this->_assertReady();
		if (!is_array($event)) {
			$reservationCode = $event;
			$event = Saf_Model::convert($event, 'event', array('username' => $username));
			if ($event['userEmail'] != "{$username}@ncsu.edu") {
				throw new Ems_Exception_Reservation_403("Attempting to mail reservation {$reservationCode} to wrong user.");
			}
		}
		$email = $event['userEmail'];
		$name = $event['userFullname'];
		if ($isUpdate && !array_key_exists('modified', $event) {
			$event['modified'] = Saf_Time::time();
		}
		$icalEvent = array_merge(
			$event, 
			array(
				'method' => Saf_Ical::METHOD_REQUEST,
				'id' => str_replace('/', '_', $event['code']),
				'sequence' => Saf_Ical::AUTO_SEQUENCE
			)
		);
		$ical = new Saf_Ical($icalEvent);
		$url = Zend_Registry::get('siteUrl') . 'reservation';
		$message = str_replace(
			array(
				'[[$location]]',
				'[[$userStart]]',
				'[[$userEnd]]',
				'[[$date]]',
				'[[$year]]',
				'[[$url]]'
			), array(
				$event['userLocation'],
				$event['userStart'],
				$event['userEnd'],
				$event['userDate'],
				$event['userYear'],
				$url
			), $message		
		);
		$subject = str_replace(
			array(
				'[[$room]]',
				'[[$date]]',
				'[[$year]]'
			), array(
				$event['userRoom'],
				$event['userDate'],
				$event['userYear']
			), $subject
		);
		$this->sendMail(array($email, $name), $subject, $message, $ical->getAttachment());
		return $this;
	}
	
	public function sendMail($to, $subject, $message, $attachment = NULL)
	{
		$this->_assertReady();
		$mail = new Zend_Mail();
		$mail->setBodyText($message);
		$mail->setFrom($this->_name, $this->_address);
		if (is_array($to)) {
			$mail->addTo($to, $name);
		} else {
			$mail->addTo($to);
		}
		$mail->setSubject($subject);
		if (!is_null($attachment)) {
			$mail->addAttachment($attachment);
		}
		$mail->send();
		return $this;
	}
	
	protected _assertReady()
	{
		if (!$this->_name || !$this->_address) {
			throw new Exception("Attempting to send mail with no sender specified: \"{$this->_name}, {$this->_address}\"");
		}
		return $this;
	}
}

Messenger_Root.php

/*
 * Singleton for a root messenger that can be globally enabled or disabled (e.g. disabled on development).
 * ::init() gets called during bootstrap, determining if the instance will send any messages or not.
 */
abstract class Messenger_Root 
{
	const NEWLINE = "\r\n";
	protected static $_enabled = FALSE;
	protected static $_instance = NULL;
	
	public static function init($config)
	{
		if (!is_null(self::$_instance) {
			return;
		}
		if (
			$config && array_key_exists('enabled', $config) 
			&& !Saf_Filter_Truthy::filter($config['enabled'])
		) {
			self::$_enabled = TRUE;
			Saf_Profiler::flag('+Messaging');
		} else {
			Saf_Profiler::flag('-Messaging');
			return;
		}
		$rootMailSender = 
			Saf_Array::keyExistsAndNotBlank('name', $config) 
			? trim($config['name'])
			: NULL;
		if (!$rootMailSender) {
			throw new Saf_Exception_Startup('No Messenger Sender Name');
		}
		$rootMailAddress = 
			Saf_Array::keyExistsAndNotBlank('address', $config) 
			? trim($config['address'])
			: NULL;
		if (!$rootMailAddress) {
			throw new Saf_Exception_Startup('No Messenger Sender Address');
		}
		try{
			self::$_instance = new Messenger($config);
		} catch (Exception $e) {
			if (!is_a($e, 'Saf_Exception_Startup') {
				throw new Saf_Exception_Startup('Failed to create Messenger', 0, $e);
			}
			throw $e;
		}
	}
	
	public static function get()
	{
		return self::$_instance;
	}
	
	public static function isEnabled()
	{
		return self::$_enabled;
	}
}

Model.php

/*
 *  class to decouple resolution to a model type from the generation of the memento 
 */
Saf_Model {
	public static function convert($identifier, $model, $parameters = array())
	{
		$className = Saf_Filter_ValidClass(ucfirst($model) . '_Model');
		if ($className) {
			$reflector = new ReflectionClass($className);
			return $reflector->getMethod('get')->invokeArgs(NULL, array($identifier, $parameters));
		} else {
			throw new Saf_Exception_Reflection("Unable to resolve model: {$model}");
		}
	}
}