import_ical.php from the WebCalendar project.
Author: Daniel Westermann-Clark
Author URI: http://dev.webadmin.ufl.edu/~dwc/
*/
require_once('import_ical.php');
define('ICAL_EVENTS_CACHE_TTL', 24 * 60 * 60); // 1 day
define('ICAL_EVENTS_CACHE_DEFAULT_EXTENSION', 'ics');
define('ICAL_EVENTS_MAX_REPEATS', '100');
if (! defined('ICAL_EVENTS_DEBUG')) define('ICAL_EVENTS_DEBUG', false);
// As defined by import_ical.php
$ICAL_EVENTS_REPEAT_INTERVALS = array(
1 => 24 * 60 * 60, // Daily
2 => 7 * 24 * 60 * 60, // Weekly
5 => 365 * 25 * 60 * 60, // Yearly
);
if (! class_exists('ICalEvents')) {
class ICalEvents {
/*
* Display up to the specified number of events that fall within
* the specified range on the specified calendar. All
* constraints are optional.
*/
function display_events($args = '') {
$r = array();
parse_str($args, $r);
if (! isset($r['url'])) {
echo "iCal Events: No URL specified\n";
return;
}
if (! isset($r['gmt_start'])) $r['gmt_start'] = null;
if (! isset($r['gmt_end'])) $r['gmt_end'] = null;
if (! isset($r['limit'])) $r['limit'] = null;
if (! isset($r['date_format'])) $r['date_format'] = '%a %b %e';
if (! isset($r['time_format'])) $r['time_format'] = '%l:%M %p';
if (! isset($r['before'])) $r['before'] = '';
if (! isset($r['after'])) $r['after'] = '';
if (! isset($r['before_date'])) $r['before_date'] = '';
if (! isset($r['after_date'])) $r['after_date'] = ': ';
if (! isset($r['use_summary'])) $r['use_summary'] = true;
if (! isset($r['before_summary'])) $r['before_summary'] = '';
if (! isset($r['after_summary'])) $r['after_summary'] = '';
if (! isset($r['use_description'])) $r['use_description'] = true;
if (! isset($r['replace_newlines_with'])) $r['replace_newlines_with'] = '
';
if (! isset($r['before_description'])) $r['before_description'] = ' - ';
if (! isset($r['after_description'])) $r['after_description'] = '';
if (! isset($r['use_location'])) $r['use_location'] = true;
if (! isset($r['before_location'])) $r['before_location'] = ' (';
if (! isset($r['after_location'])) $r['after_location'] = ')';
if (! isset($r['use_url'])) $r['use_url'] = true;
if (! isset($r['echo'])) $r['echo'] = true;
ICalEvents::do_display_events($r['url'], $r['gmt_start'], $r['gmt_end'], $r['limit'], $r['date_format'], $r['time_format'], $r['before'], $r['after'], $r['before_date'], $r['after_date'], $r['use_summary'], $r['before_summary'], $r['after_summary'], $r['use_description'], $r['before_description'], $r['after_description'], $r['replace_newlines_with'], $r['use_location'], $r['before_location'], $r['after_location'], $r['use_url'], $r['echo']);
}
/*
* Helper method for displaying events. Note that the API of
* this method may change, so you should use display_events.
*/
function do_display_events($url, $gmt_start, $gmt_end, $limit, $date_format, $time_format, $before, $after, $before_date, $after_date, $use_summary, $before_summary, $after_summary, $use_description, $before_description, $after_description, $replace_newlines_with, $use_location, $before_location, $after_location, $use_url, $echo) {
$events = ICalEvents::get_events($url, $gmt_start, $gmt_end, $limit);
$output = '';
foreach ($events as $event) {
$output .= $before;
$output .= $before_date;
if (ICalEvents::is_all_day($event['StartTime'], $event['EndTime'])) {
$output .= htmlentities(strftime($date_format, $event['StartTime']));
}
else {
$output .= htmlentities(ICalEvents::format_date_range($event['StartTime'], $event['EndTime'], $date_format, $time_format));
}
$output .= $after_date;
if ($use_summary and $event['Summary']) {
$output .= $before_summary;
if ($use_url and $event['URL']) {
$output .= '';
}
$output .= htmlentities($event['Summary']);
if ($use_url and $event['URL']) {
$output .= '';
}
$output .= $after_summary;
}
if ($use_description and $event['Description']) {
$output .= $before_description;
if ($replace_newlines_with) {
$output .= str_replace("\n", $replace_newlines_with, htmlentities($event['Description']));
}
$output .= $after_description;
}
if ($use_location and $event['Location']) {
$output .= $before_location . htmlentities($event['Location']) . $after_location;
}
if ($event['UID']) {
$output .= '';
}
$output .= $after . "\n";
}
if ($echo) {
echo $output;
}
return $output;
}
/*
* Return a list of events from the specified calendar. For
* more on what's available, read import_ical.php or use
* print_r.
*/
function get_events($url, $gmt_start = null, $gmt_end = null, $limit = null) {
$file = ICalEvents::cache_url($url);
$events = parse_ical($file);
if (! is_array($events) or count($events) <= 0) {
echo "iCal Events: Error parsing calendar";
return;
}
$events = ICalEvents::constrain($events, $gmt_start, $gmt_end, $limit);
return $events;
}
/*
* Cache the specified URL and return the name of the
* destination file.
*/
function cache_url($url) {
$file = ICalEvents::get_cache_file($url);
if (! file_exists($file) or time() - filemtime($file) >= ICAL_EVENTS_CACHE_TTL) {
$src = fopen($url, 'r') or die("Error opening $url");
$dest = fopen($file, 'w') or die("Error opening $file");
while ($data = fread($src, 8192)) {
fwrite($dest, $data);
}
fclose($src);
fclose($dest);
}
return $file;
}
/*
* Return the full path to the cache file for the specified URL.
*/
function get_cache_file($url) {
return ICalEvents::get_cache_path() . ICalEvents::get_cache_filename($url);
}
/*
* Attempt to create the cache directory if it doesn't exist.
* Return the path if successful.
*/
function get_cache_path() {
$cache_path = trailingslashit(ABSPATH . 'wp-content/ical-events-cache');
if (! file_exists($cache_path)) {
if (is_writable(dirname($cache_path))) {
if (! mkdir($cache_path, 0777)) {
die("Error creating cache directory ($cache_path)");
}
}
else {
die("Your cache directory ($cache_path) needs to be writable for this plugin to work. Double-check it. Deactivate the iCal Events plugin.");
}
}
return $cache_path;
}
/*
* Return the cache filename for the specified URL.
*/
function get_cache_filename($url) {
$extension = ICAL_EVENTS_CACHE_DEFAULT_EXTENSION;
$matches = array();
if (preg_match('/\.(\w+)$/', $url, $matches)) {
$extension = $matches[1];
}
return md5($url) . ".$extension";
}
/*
* Constrain the list of events to those which fall between the
* specified start and end time, up to the specified number of
* events.
*/
function constrain($events, $gmt_start = null, $gmt_end = null, $limit = null) {
$repeats = ICalEvents::collapse_repeats($events, $gmt_start, $gmt_end, $limit);
if (is_array($repeats) and count($repeats) > 0) {
$events = array_merge($events, $repeats);
}
$events = ICalEvents::sort_by_key($events, 'StartTime');
if (! $limit) $limit = count($events);
$constrained = array();
$count = 0;
foreach ($events as $event) {
if (ICalEvents::falls_between($event, $gmt_start, $gmt_end)) {
$constrained[] = $event;
++$count;
}
if ($count >= $limit) break;
}
return $constrained;
}
/*
* Sort the specified associative array by the specified key.
* Originally from
* http://us2.php.net/manual/en/function.usort.php.
*/
function sort_by_key($data, $key) {
// Reverse sort
$compare = create_function('$a, $b', 'if ($a["' . $key . '"] == $b["' . $key . '"]) { return 0; } else { return ($a["' . $key . '"] < $b["' . $key . '"]) ? -1 : 1; }');
usort($data, $compare);
return $data;
}
/*
* Return true iff the specified event falls between the given
* start and end times.
*/
function falls_between($event, $gmt_start, $gmt_end) {
$falls_between = false;
if (ICAL_EVENTS_DEBUG) {
print "UID = [{$event['UID']}], StartTime = [{$event['StartTime']}], EndTime = [{$event['EndTime']}], gmt_start = [$gmt_start], gmt_end = [$gmt_end]\n";
}
if ($event['Untimed'] or $event['Duration'] == 1440) {
// Keep all-day events for the whole day
$falls_between = ((! $gmt_start or $gmt_start <= $event['StartTime'] + 86400)
and (! $gmt_end or $gmt_end >= $event['EndTime']));
}
else {
$falls_between = ((! $gmt_start or $gmt_start <= $event['StartTime'])
and (! $gmt_end or $gmt_end >= $event['EndTime']));
}
return $falls_between;
}
/*
* Collapse repeating events down to nonrepeating events at the
* corresponding repeat time.
*/
function collapse_repeats($events, $gmt_start, $gmt_end, $limit) {
$repeats = array();
foreach ($events as $event) {
if (isset($event['Repeat'])) {
$r = ICalEvents::get_repeats_between($event, $gmt_start, $gmt_end, $limit);
if (is_array($r) and count($r) > 0) {
$repeats = array_merge($repeats, $r);
}
}
}
return $repeats;
}
/*
* If the specified event repeats between the given start and
* end times, return one or more nonrepeating events at the
* corresponding times.
* TODO: Only handles some types of repeating events
* TODO: Check for exceptions to the RRULE
*/
function get_repeats_between($event, $gmt_start, $gmt_end, $limit) {
global $ICAL_EVENTS_REPEAT_INTERVALS;
$rrule = $event['Repeat'];
$repeats = array();
if (isset($ICAL_EVENTS_REPEAT_INTERVALS[$rrule['Interval']])) {
$interval = $ICAL_EVENTS_REPEAT_INTERVALS[$rrule['Interval']] * ($rrule['Frequency'] ? $rrule['Frequency'] : 1);
$repeat_days = ICalEvents::get_repeat_days($rrule['RepeatDays']);
$count = 0;
while ($count++ <= ICAL_EVENTS_MAX_REPEATS) {
if ($repeat_days) {
foreach ($repeat_days as $repeat_day) {
$repeat = ICalEvents::get_repeat($event, $interval, $count, $repeat_day);
if (ICalEvents::falls_between($repeat, $gmt_start, $gmt_end)) $repeats[] = $repeat;
}
}
else {
$repeat = ICalEvents::get_simple_repeat($event, $interval, $count);
if (ICalEvents::falls_between($repeat, $gmt_start, $gmt_end)) $repeats[] = $repeat;
}
// Don't repeat past the RRULE-defined end time, if one exists
if ($rrule['EndTime'] and $event['StartTime'] + $interval * $count >= $rrule['EndTime']) break;
// Don't repeat past the user-defined limit, if one exists
if ($limit and $count >= $limit) break;
}
}
else {
echo "Unknown repeat interval: ${rr['Interval']}";
}
return $repeats;
}
/*
* Given a string like 'nynynyn' from import_ical.php, return
* an array containing the weekday numbers (0 = Sun, 6 = Sat).
*/
function get_repeat_days($yes_no) {
$repeat_days = array();
for ($i = 0; $i < strlen($yes_no); $i++) {
if ($yes_no[$i] == 'y') $repeat_days[] = $i;
}
return $repeat_days;
}
/*
* Using the specified event as a base, return the repeating
* event the given number of intervals (in seconds) in the
* future on the repeat day (0 = Sun, 6 = Sat).
*/
function get_repeat($event, $interval, $count, $repeat_day) {
$repeat = ICalEvents::get_simple_repeat($event, $interval, $count);
$date = getdate($event['StartTime']);
$wday = $date['wday'];
$offset = ($repeat_day - $wday) * 86400;
$repeat['StartTime'] += $offset;
if (isset($repeat['EndTime'])) {
$repeat['EndTime'] += $offset;
}
return $repeat;
}
/*
* Using the specified event as a base, return the repeating
* event the given number of intervals (in seconds) in the
* future.
*/
function get_simple_repeat($event, $interval, $count) {
$duration = 0;
if ($event['Duration']) {
$duration = $event['Duration'] * 60;
}
else if ($event['EndTime']) {
$duration = $event['EndTime'] - $event['StartTime'];
}
$repeat = $event;
unset($repeat['Repeat']);
$repeat['StartTime'] += $interval * $count;
// Default to no duration
$repeat['EndTime'] = $repeat['StartTime'];
if ($duration > 0) {
$repeat['EndTime'] = $repeat['StartTime'] + $duration;
}
// Handle timezone changes since the initial event date
$offset = date('Z', $event['StartTime']) - date('Z', $repeat['StartTime']);
$repeat['StartTime'] += $offset;
$repeat['EndTime'] += $offset;
return $repeat;
}
/*
* Return a string representing the specified date range.
*/
function format_date_range($gmt_start, $gmt_end, $date_format, $time_format, $separator = ' - ') {
$output = '';
if (ICalEvents::is_today($gmt_start)) {
$output .= strftime($time_format, $gmt_start);
}
else {
$output .= strftime("$date_format $time_format", $gmt_start);
}
if ($gmt_start != $gmt_end) {
$output .= $separator;
if (ICalEvents::is_today($gmt_end) or ICalEvents::is_same_day($gmt_start, $gmt_end)) {
$output .= strftime($time_format, $gmt_end);
}
else {
$output .= strftime("$date_format $time_format", $gmt_end);
}
}
$output = trim(preg_replace('/\s{2,}/', ' ', $output));
return $output;
}
/*
* Given a time value (as seconds since the epoch), return true
* iff the time falls on the current day.
*/
function is_today($gmt) {
return ICalEvents::is_same_day(time(), $gmt);
}
/*
* Return true iff the two times span exactly 24 hours, from
* midnight one day to midnight the next.
*/
function is_all_day($gmt1, $gmt2) {
$local1 = localtime(($gmt1 <= $gmt2 ? $gmt1 : $gmt2), 1);
$local2 = localtime(($gmt1 <= $gmt2 ? $gmt2 : $gmt1), 1);
return (abs($gmt2 - $gmt1) == 86400
and $local1['tm_hour'] == 0
and $local1['tm_year'] == $local2['tm_year']);
}
/*
* Return true iff the two specified times fall on the same day.
*/
function is_same_day($gmt1, $gmt2) {
$local1 = localtime($gmt1, 1);
$local2 = localtime($gmt2, 1);
return ($local1['tm_mday'] == $local2['tm_mday']
and $local1['tm_mon'] == $local2['tm_mon']
and $local1['tm_year'] == $local2['tm_year']);
}
}
}
?>