131 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
			
		
		
	
	
			131 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			PHP
		
	
	
	
	
	
| <?php
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| 
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| //--------------------------------------------------------------------------------------------------
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| // Utilities for our event-fetching scripts.
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| //
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| // Requires PHP 5.2.0 or higher.
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| //--------------------------------------------------------------------------------------------------
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| 
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| // PHP will fatal error if we attempt to use the DateTime class without this being set.
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| date_default_timezone_set('UTC');
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| 
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| 
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| class Event {
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| 
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| 	// Tests whether the given ISO8601 string has a time-of-day or not
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| 	const ALL_DAY_REGEX = '/^\d{4}-\d\d-\d\d$/'; // matches strings like "2013-12-29"
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| 
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| 	public $title;
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| 	public $allDay; // a boolean
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| 	public $start; // a DateTime
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| 	public $end; // a DateTime, or null
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| 	public $properties = array(); // an array of other misc properties
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| 
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| 
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| 	// Constructs an Event object from the given array of key=>values.
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| 	// You can optionally force the timezone of the parsed dates.
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| 	public function __construct($array, $timezone=null) {
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| 
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| 		$this->title = $array['title'];
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| 
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| 		if (isset($array['allDay'])) {
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| 			// allDay has been explicitly specified
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| 			$this->allDay = (bool)$array['allDay'];
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| 		}
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| 		else {
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| 			// Guess allDay based off of ISO8601 date strings
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| 			$this->allDay = preg_match(self::ALL_DAY_REGEX, $array['start']) &&
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| 				(!isset($array['end']) || preg_match(self::ALL_DAY_REGEX, $array['end']));
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| 		}
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| 
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| 		if ($this->allDay) {
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| 			// If dates are allDay, we want to parse them in UTC to avoid DST issues.
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| 			$timezone = null;
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| 		}
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| 
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| 		// Parse dates
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| 		$this->start = parseDateTime($array['start'], $timezone);
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| 		$this->end = isset($array['end']) ? parseDateTime($array['end'], $timezone) : null;
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| 
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| 		// Record misc properties
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| 		foreach ($array as $name => $value) {
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| 			if (!in_array($name, array('title', 'allDay', 'start', 'end'))) {
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| 				$this->properties[$name] = $value;
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| 			}
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| 		}
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| 	}
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| 
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| 
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| 	// Returns whether the date range of our event intersects with the given all-day range.
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| 	// $rangeStart and $rangeEnd are assumed to be dates in UTC with 00:00:00 time.
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| 	public function isWithinDayRange($rangeStart, $rangeEnd) {
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| 
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| 		// Normalize our event's dates for comparison with the all-day range.
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| 		$eventStart = stripTime($this->start);
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| 
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| 		if (isset($this->end)) {
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| 			$eventEnd = stripTime($this->end); // normalize
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| 		}
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| 		else {
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| 			$eventEnd = $eventStart; // consider this a zero-duration event
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| 		}
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| 
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| 		// Check if the two whole-day ranges intersect.
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| 		return $eventStart < $rangeEnd && $eventEnd >= $rangeStart;
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| 	}
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| 
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| 
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| 	// Converts this Event object back to a plain data array, to be used for generating JSON
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| 	public function toArray() {
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| 
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| 		// Start with the misc properties (don't worry, PHP won't affect the original array)
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| 		$array = $this->properties;
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| 
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| 		$array['title'] = $this->title;
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| 
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| 		// Figure out the date format. This essentially encodes allDay into the date string.
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| 		if ($this->allDay) {
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| 			$format = 'Y-m-d'; // output like "2013-12-29"
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| 		}
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| 		else {
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| 			$format = 'c'; // full ISO8601 output, like "2013-12-29T09:00:00+08:00"
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| 		}
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| 
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| 		// Serialize dates into strings
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| 		$array['start'] = $this->start->format($format);
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| 		if (isset($this->end)) {
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| 			$array['end'] = $this->end->format($format);
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| 		}
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| 
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| 		return $array;
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| 	}
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| 
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| }
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| 
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| 
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| // Date Utilities
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| //----------------------------------------------------------------------------------------------
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| 
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| 
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| // Parses a string into a DateTime object, optionally forced into the given timezone.
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| function parseDateTime($string, $timezone=null) {
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| 	$date = new DateTime(
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| 		$string,
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| 		$timezone ? $timezone : new DateTimeZone('UTC')
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| 			// Used only when the string is ambiguous.
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| 			// Ignored if string has a timezone offset in it.
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| 	);
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| 	if ($timezone) {
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| 		// If our timezone was ignored above, force it.
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| 		$date->setTimezone($timezone);
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| 	}
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| 	return $date;
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| }
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| 
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| 
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| // Takes the year/month/date values of the given DateTime and converts them to a new DateTime,
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| // but in UTC.
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| function stripTime($datetime) {
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| 	return new DateTime($datetime->format('Y-m-d'));
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| }
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