class.ical.php

<?php

/**
 * ICAL CLASS
 * OUTPUT AN ICS FILE TO BROWSER OR HARDDRIVE
 *
 * Please refer to http://tools.ietf.org/html/rfc5545 if infos are needed
 * 
 * @author ANDY KAYL
 * @version 0.2
 * @license http://opensource.org/licenses/BSD-3-Clause
 *
 * Copyright (c) 2017, ND.K
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list of conditions and
 * the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 *
 * Neither the name of the <ORGANIZATION> nor the names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

class iCal {
	
	/**
	 * CLASS CONSTRUCTOR
	 */
	
	public function __construct() {
		$this->prodid = "PHP iCal Generator";
		$this->alarmdesc = "You gotta do what you gotta do! You have a job soon...";
		$this->alarmtrigger = 60;
		$this->refresh_ttl = 60;
		$this->status = "CONFIRMED";
		$this->events = array();
		$this->evnum = null;
		return true;
	}
	
	/**
	 * START A NEW EVENT
	 * @var NONE
	 * @return BOOL TRUE
	 */
	
	public function NewEvent() {
		$num = count($this->events);
		$this->evnum =& $num;
		$this->events[$num] = array(
			"data" => array(),
			"alarms" => array(),
			"custom" => array()
		);
		return true;
	}
	
	/**
	 * SET PRODUCT ID
	 * @var STRING PRODUCT ID STRING
	 * @return BOOL TRUE
	 */
	
	public function SetProductID($string) {
		$this->prodid = $string;
		return true;
	}
	
	/**
	 * SET THE REFRESH INTERVAL
	 * @var INT MINUTES
	 * @return BOOL TRUE
	 */
	
	public function SetRefresh($minutes) {
		$this->refresh_ttl = (int) $minutes;
		return true;
	}
	
	/**
	 * ADD EVENT SUMMARY TEXT
	 * @var STRING SUMMARY TEXT
	 * @return BOOL TRUE
	 */
	
	public function SetTitle($string) {
		$this->events[$this->evnum]['data']['title'] = preg_replace("/(<br[ ]?\/?>|\n)/", "\\n", $string);
		return true;
	}
	
	/**
	 * ADD DESCRIPTION TEXT
	 * @var STRING DESCRIPTION
	 * @return BOOL TRUE
	 */
	
	public function SetDescription($string) {
		$this->events[$this->evnum]['data']['description'] = preg_replace("/(<br[ ]?\/?>|\n)/", "\\n", $string);
		return true;
	}
	
	/**
	 * ADD DATES TO EVENT
	 * @var STRING BEGIN DATE (Y-M-D H:S)
	 * @var STRING END DATE (Y-M-D H:S)
	 * @return BOOL TRUE
	 */
	
	public function SetDates($begin, $end) {
		$this->events[$this->evnum]['data']['begin_date'] = date("Ymd\THis", strtotime($begin));
		$this->events[$this->evnum]['data']['end_date'] = date("Ymd\THis", strtotime($end));
		return true;
	}
	
	/**
	 * SET LOCATION
	 * @var STRING LOCATION NAME
	 * @return BOOL TRUE
	 */
	
	public function SetLocation($string) {
		$this->events[$this->evnum]['data']['location'] = $string;
		return true;
	}
	
	/**
	 * ADD CUSTOM ICAL PROPERTY
	 * @var STRING PROPERTY NAME
	 * @var STRING PROPERTY VALUE
	 * @return BOOL TRUE
	 */
	
	public function AddCustom($property, $value) {
		$property = mb_strtoupper($property);
		$this->events[$this->evnum]['custom'][$property] = $value;
		return true;
	}
	
	/**
	 * SET ALARM
	 * @var STRING TYPE => DISPLAY (DEFAULT), AUDIO (UNSUPPORTED), EMAIL (UNSUPPORTED)
	 * @return BOOL TRUE
	 */
	
	public function SetAlarm($type="display") {
		$type = mb_strtoupper($type);
		$num = count($this->events[$this->evnum]['alarms']);
		$this->alnum =& $num;
		$this->events[$this->evnum]['alarms'][$this->alnum]['type'] = $type;
		return true;
	}
	
	/**
	 * SET ALARM TEXT TO DISPLAY
	 * @var STRING MESSAGE TEXT
	 * @return BOOL TRUE
	 */
	
	public function SetAlarmText($string) {
		$this->events[$this->evnum]['alarms'][$this->alnum]['description'] = $string;
		return true;
	}
	
	/**
	 * SET ALARM TRIGGER
	 * @var INT NUMBER OF MINUTES BEFORE EVENT
	 * @return BOOL TRUE
	 */
	
	public function SetAlarmTrigger($minutes) {
		$minutes = abs((int) $minutes);
		$this->events[$this->evnum]['alarms'][$this->alnum]['trigger'] = $minutes;
		return true;
	}
	
	/**
	 * SET EVENT STATUS
	 * @var STRING STATUS => TENTATIVE, CONFIRMED, CANCELLED
	 * @return BOOL TRUE
	 */
	
	public function SetStatus($status) {
		$status = mb_strtoupper($status);
		$this->events[$this->evnum]['data']['status'] = $status;
		return true;
	}
	
	/**
	 * STORE CONTENT TO FILE
	 * @var STRING CALENDAR
	 * @var STRING FILENAME
	 * @return BOOL TRUE/FALSE
	 */
	
	private function StoreFile($content, $destfile) {
		try {
			$fh = fopen($destfile, "w");
			if (!$fh) {
				throw new Exception("file could not be created");
			}
			$ret_write = fwrite($fh, $content);
			if (!$ret_write) {
				throw new Exception("Could not write content to file");
			}
			fclose($fh);
			return true;
		}
		catch (Exception $e) {
			print $e->getMessage();
			return false;
		}
	}
	
	/**
	 * CLEAN AND FORMAT EVENT ENTRIES
	 * @VAR NONE
	 * @return BOOL TRUE
	 */
	
	private function EncodeValues() {
		foreach($this->events as $i => $event) {
			foreach($event['data'] as $key => $data) {
				$this->events[$i]['data'][$key] = html_entity_decode($data);
			}
			foreach ($event['custom'] as $key => $custom) {
				$this->events[$i]['custom'][$key] = html_entity_decode($custom);
			}
			foreach ($event['alarms'] as $j => $alarms) {
				foreach ($alarms as $key => $data) {
					$this->events[$i]['alarms'][$j][$key] = html_entity_decode($data);
				}
			}
		}
		return true;
	}
	
	/**
	 * WRITE ICAL DATA TO BROWSER OR FILE
	 * @var STRING DESTINATION FILE
	 * @return BOOL TRUE OR FALSE
	 */
	
	public function Write($destfile=false) {
		$this->EncodeValues();
		$cal = "BEGIN:VCALENDAR\n";
		$cal .= "PRODID:-//{$this->prodid}//EN\n";
		$cal .= "VERSION:2.0\n";
		$cal .= "METHOD:PUBLISH\n";
		$cal .= "X-PUBLISHED-TTL:PT{$this->refresh_ttl}M\n";
		foreach ($this->events as $event) {
			$cal .= "BEGIN:VEVENT\n";
			$cal .= "CLASS:PUBLIC\n";
			$cal .= "CREATED:".date("Ymd\THis", time())."\n";
			$cal .= "SUMMARY:{$event['data']['title']}\n";
			$status = (!empty($event['status'])) ? $event['status'] : mb_strtoupper($this->status);
			$cal .= "STATUS:{$status}\n";
			if (!empty($event['data']['description'])) {
				$cal .= "DESCRIPTION:{$event['data']['description']}\n";
			}
			if (!empty($event['data']['location'])) {
				$cal .= "LOCATION:{$event['data']['location']}\n";
			}
			$cal .= "DTSTART:{$event['data']['begin_date']}\n";
			$cal .= "DTEND:{$event['data']['end_date']}\n";
			$cal .= "DTSTAMP:".date("Ymd\THis", time())."\n";
			$cal .= "UID:".md5(uniqid("", true))."\n";
			foreach($event['custom'] as $prop => $val) {
				$cal .= "{$prop}:{$val}\n";
			}
			foreach ($event['alarms'] as $alarms) {
				$cal .= "BEGIN:VALARM\n";
				$cal .= "ACTION:{$alarms['type']}\n";
				$alarmtrigger = (!empty($alarms['trigger'])) ? $alarms['trigger'] : $this->alarmtrigger;
				$cal .= "TRIGGER:-PT{$alarmtrigger}M\n";
				$alarmdesc = (!empty($alarms['description'])) ? $alarms['description'] : $this->alarmdesc;
				$cal .= "DESCRIPTION:{$alarmdesc}\n";
				$cal .= "END:VALARM\n";
			}
			$cal .= "END:VEVENT\n";
		}
		$cal .= "END:VCALENDAR\n";
		if (!$destfile) {
			header("Content-Type: text/Calendar");
			header("Content-Disposition: attachment; filename=events.ics");
			print $cal;
			return true;
		}
		else {
			return $this->StoreFile($cal, $destfile);
		}
	}
	
}

?>