IcalendarPropertyDtstart.php

<?php

class IcalendarPropertyDtstart extends IcalendarProperty
{
	public $name = 'DTSTART';
	public $val_type = RFC2445_TYPE_DATE_TIME;

	public function construct()
	{
		$this->valid_parameters = [
			'VALUE' => RFC2445_OPTIONAL | RFC2445_ONCE,
			'TZID' => RFC2445_OPTIONAL | RFC2445_ONCE,
			RFC2445_XNAME => RFC2445_OPTIONAL,
		];
	}

	public function isValidValue($value)
	{
		if (!parent::isValidValue($value)) {
			return false;
		}
		// If present in a FREEBUSY component, must be in UTC format
		if ($this->parent_component == 'VFREEBUSY' && substr($value, -1) != 'Z') {
			return false;
		}

		return true;
	}

	public function isValidParameter($parameter, $value)
	{
		$parameter = strtoupper($parameter);

		if (!parent::isValidParameter($parameter, $value)) {
			return false;
		}
		if ($parameter == 'VALUE' && !($value == 'DATE' || $value == 'DATE-TIME')) {
			return false;
		}

		return true;
	}
}