rss-bridge/lib/validation.php

<?php
function validateData(&$data, $parameters)
{
	$validateTextValue = function ($value, $pattern = null) {
		if (!is_null($pattern)) {
			$filteredValue = filter_var($value, FILTER_VALIDATE_REGEXP, array('options' => array(
					'regexp' => '/^' . $pattern . '$/'
				))
			);
		} else {
			$filteredValue = filter_var($value);
		}

		if ($filteredValue === false) {
			return null;
		}

		return $filteredValue;
	};

	$validateNumberValue = function ($value) {
		$filteredValue = filter_var($value, FILTER_VALIDATE_INT);

		if ($filteredValue === false && !empty($value)) {
			return null;
		}

		return $filteredValue;
	};

	$validateCheckboxValue = function ($value) {
		$filteredValue = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);

		if (is_null($filteredValue)) {
			return null;
		}

		return $filteredValue;
	};

	$validateListValue = function ($value, $expectedValues) {
		$filteredValue = filter_var($value);

		if ($filteredValue === false) {
			return null;
		}

		if (!in_array($filteredValue, $expectedValues)) { // Check sub-values?
			foreach ($expectedValues as $subName => $subValue) {
				if (is_array($subValue) && in_array($filteredValue, $subValue)) {
					return $filteredValue;
				}
			}
			return null;
		}

		return $filteredValue;
	};

	if (!is_array($data)) {
		return false;
	}

	foreach ($data as $name => $value) {
		$registered = false;
		foreach ($parameters as $context => $set) {
			if (array_key_exists($name, $set)) {
				$registered = true;
				if (!isset($set[$name]['type'])) {
					$set[$name]['type'] = 'text';
				}

				switch ($set[$name]['type']) {
				case 'number':
					$data[$name] = $validateNumberValue($value);
					break;
				case 'checkbox':
					$data[$name] = $validateCheckboxValue($value);
					break;
				case 'list':
					$data[$name] = $validateListValue($value, $set[$name]['values']);
					break;
				default:
				case 'text':
					if (isset($set[$name]['pattern'])) {
						$data[$name] = $validateTextValue($value, $set[$name]['pattern']);
					} else {
						$data[$name] = $validateTextValue($value);
					}
					break;
				}

				if (is_null($data[$name])) {
					echo 'Parameter \'' . $name . '\' is invalid!' . PHP_EOL;
					return false;
				}
			}
		}

		if (!$registered) {
			return false;
		}
	}

	return true;
}