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@martinjinda
Forked from jakebellacera/ICS.php
Created March 6, 2018 11:37
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A convenient script to generate iCalendar (.ics) files on the fly in PHP.

PHP to ICS

This gist contains a convenient script to generate iCalendar (.ics) files on the fly in PHP.

Basic usage

include 'ICS.php'

$properties = array(
  'dtstart' => 'now',
  'dtend' => 'now + 30 minutes'
);

$ics = new ICS($properties);
$ics_file_contents = $ics->to_string();

Available properties

  • description - string description of the event.
  • dtend - date/time stamp designating the end of the event. You can use either a DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
  • dtstart - date/time stamp designating the start of the event. You can use either a DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
  • location - string address or description of the location of the event.
  • summary - string short summary of the event - usually used as the title.
  • url - string url to attach to the the event. Make sure to add the protocol (http:// or https://).

Detailed examples

Button that downloads an ICS file when clicked

This example contains a form on the front-end that submits to a PHP script that initiates a download of an ICS file. This example uses hidden form fields to set the properties dynamically.

index.html

<form method="post" action="/download-ics.php">
  <input type="hidden" name="date_start" value="2017-1-16 9:00AM">
  <input type="hidden" name="date_end" value="2017-1-16 10:00AM">
  <input type="hidden" name="location" value="123 Fake St, New York, NY">
  <input type="hidden" name="description" value="This is my description">
  <input type="hidden" name="summary" value="This is my summary">
  <input type="hidden" name="url" value="http://example.com">
  <input type="submit" value="Add to Calendar">
</form>

download-ics.php

<?php

include 'ICS.php';

header('Content-Type: text/calendar; charset=utf-8');
header('Content-Disposition: attachment; filename=invite.ics');

$ics = new ICS(array(
  'location' => $_POST['location'],
  'description' => $_POST['description'],
  'dtstart' => $_POST['date_start'],
  'dtend' => $_POST['date_end'],
  'summary' => $_POST['summary'],
  'url' => $_POST['url']
));

echo $ics->to_string();
<?php
/**
* ICS.php
* =======
* Use this class to create an .ics file.
*
* Usage
* -----
* Basic usage - generate ics file contents (see below for available properties):
* $ics = new ICS($props);
* $ics_file_contents = $ics->to_string();
*
* Setting properties after instantiation
* $ics = new ICS();
* $ics->set('summary', 'My awesome event');
*
* You can also set multiple properties at the same time by using an array:
* $ics->set(array(
* 'dtstart' => 'now + 30 minutes',
* 'dtend' => 'now + 1 hour'
* ));
*
* Available properties
* --------------------
* description
* String description of the event.
* dtend
* A date/time stamp designating the end of the event. You can use either a
* DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
* dtstart
* A date/time stamp designating the start of the event. You can use either a
* DateTime object or a PHP datetime format string (e.g. "now + 1 hour").
* location
* String address or description of the location of the event.
* summary
* String short summary of the event - usually used as the title.
* url
* A url to attach to the the event. Make sure to add the protocol (http://
* or https://).
*/
class ICS {
const DT_FORMAT = 'Ymd\THis\Z';
protected $properties = array();
private $available_properties = array(
'description',
'dtend',
'dtstart',
'location',
'summary',
'url'
);
public function __construct($props) {
$this->set($props);
}
public function set($key, $val = false) {
if (is_array($key)) {
foreach ($key as $k => $v) {
$this->set($k, $v);
}
} else {
if (in_array($key, $this->available_properties)) {
$this->properties[$key] = $this->sanitize_val($val, $key);
}
}
}
public function to_string() {
$rows = $this->build_props();
return implode("\r\n", $rows);
}
private function build_props() {
// Build ICS properties - add header
$ics_props = array(
'BEGIN:VCALENDAR',
'VERSION:2.0',
'PRODID:-//hacksw/handcal//NONSGML v1.0//EN',
'CALSCALE:GREGORIAN',
'BEGIN:VEVENT'
);
// Build ICS properties - add header
$props = array();
foreach($this->properties as $k => $v) {
$props[strtoupper($k . ($k === 'url' ? ';VALUE=URI' : ''))] = $v;
}
// Set some default values
$props['DTSTAMP'] = $this->format_timestamp('now');
$props['UID'] = uniqid();
// Append properties
foreach ($props as $k => $v) {
$ics_props[] = "$k:$v";
}
// Build ICS properties - add footer
$ics_props[] = 'END:VEVENT';
$ics_props[] = 'END:VCALENDAR';
return $ics_props;
}
private function sanitize_val($val, $key = false) {
switch($key) {
case 'dtend':
case 'dtstamp':
case 'dtstart':
$val = $this->format_timestamp($val);
break;
default:
$val = $this->escape_string($val);
}
return $val;
}
private function format_timestamp($timestamp) {
$dt = new DateTime($timestamp);
return $dt->format(self::DT_FORMAT);
}
private function escape_string($str) {
return preg_replace('/([\,;])/','\\\$1', $str);
}
}
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