IcalendarPropertyRequeststatus.php

<?php

class IcalendarPropertyRequeststatus extends IcalendarProperty
{
	// IMPORTANT NOTE: This property value includes TEXT fields
	// separated by semicolons. Unfortunately, auto-value-formatting
	// cannot be used in this case. As an exception, the value passed
	// to this property MUST be already escaped.

	public $name = 'REQUEST-STATUS';
	public $val_type = RFC2445_TYPE_TEXT;

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

	public function isValidValue($value)
	{
		if (!is_string($value) || empty($value)) {
			return false;
		}

		$len = strlen($value);
		$parts = [];
		$from = 0;
		$escch = false;

		for ($i = 0; $i < $len; ++$i) {
			if ($value[$i] == ';' && !$escch) {
				// Token completed
				$parts[] = substr($value, $from, $i - $from);
				$from = $i + 1;
				continue;
			}
			$escch = ($value[$i] == '\\');
		}
		// Add one last token with the remaining text; if the value
		// ended with a ';' it was illegal, so check that this token
		// is not the empty string.
		$parts[] = substr($value, $from);

		$count = count($parts);

		// May have 2 or 3 tokens (last one is optional)
		if ($count != 2 && $count != 3) {
			return false;
		}

		// REMEMBER: if ANY part is empty, we have an illegal value
		// First token must be hierarchical numeric status (3 levels max)
		if (strlen($parts[0]) == 0) {
			return false;
		}

		if ($parts[0][0] < '1' || $parts[0][0] > '4') {
			return false;
		}

		$len = strlen($parts[0]);

		// Max 3 levels, and can't end with a period
		if ($len > 5 || $parts[0][$len - 1] == '.') {
			return false;
		}

		for ($i = 1; $i < $len; ++$i) {
			if (($i & 1) == 1 && $parts[0][$i] != '.') {
				// Even-indexed chars must be periods
				return false;
			} elseif (($i & 1) == 0 && ($parts[0][$i] < '0' || $parts[0][$i] > '9')) {
				// Odd-indexed chars must be numbers
				return false;
			}
		}

		// Second and third tokens must be TEXT, and already escaped, so
		// they are not allowed to have UNESCAPED semicolons, commas, slashes,
		// or any newlines at all

		for ($i = 1; $i < $count; ++$i) {
			if (strpos($parts[$i], "\n") !== false) {
				return false;
			}

			$len = strlen($parts[$i]);
			if ($len == 0) {
				// Cannot be empty
				return false;
			}

			$parts[$i] .= '#'; // This guard token saves some conditionals in the loop

			for ($j = 0; $j < $len; ++$j) {
				$thischar = $parts[$i][$j];
				$nextchar = $parts[$i][$j + 1];
				if ($thischar == '\\') {
					// Next char must now be one of ";,\nN"
					if ($nextchar != ';' && $nextchar != ',' && $nextchar != '\\' &&
						$nextchar != 'n' && $nextchar != 'N') {
						return false;
					}

					// OK, this escaped sequence is correct, bypass next char
					++$j;
					continue;
				}
				if ($thischar == ';' || $thischar == ',' || $thischar == '\\') {
					// This wasn't escaped as it should
					return false;
				}
			}
		}

		return true;
	}

	public function setValueICal($value)
	{
		// Must override this, otherwise the value would be quoted again
		if ($this->isValidValue($value)) {
			$this->value = $value;

			return true;
		}

		return false;
	}
}