[ParameterValidator] Refactor 'validation' into 'ParameterValidator'

Adds a new class 'ParameterValidator' to replace the functions from
'validator.php', separating private functions from 'validateData' to
class private functions in the process.

Instead of echoing error messages, adds messages to a private variable,
accessible via 'getInvalidParameters'.

BridgeAbstract now adds invalid parameter names to the error message.

lib/ParameterValidator.php

@@ -0,0 +1,123 @@
+<?php
+/**
+ * Implements a validator for bridge parameters
+ */
+class ParameterValidator {
+	private $invalid = array();
+
+	private function addInvalidParameter($name, $reason){
+		$this->invalid[] = array(
+			'name' => $name,
+			'reason' => $reason
+		);
+	}
+
+	/**
+	 * Returns an array of invalid parameters, where each element is an
+	 * array of 'name' and 'reason'.
+	 */
+	public function getInvalidParameters() {
+		return $this->invalid;
+	}
+
+	private function validateTextValue($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 $filteredValue;
+	}
+
+	private function validateNumberValue($value){
+		$filteredValue = filter_var($value, FILTER_VALIDATE_INT);
+
+		if($filteredValue === false)
+			return null;
+
+		return $filteredValue;
+	}
+
+	private function validateCheckboxValue($value){
+		return filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
+	}
+
+	private function validateListValue($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;
+	}
+
+	/**
+	 * Checks if all required parameters are supplied by the user
+	 * @param $data An array of parameters provided by the user
+	 * @param $parameters An array of bridge parameters
+	 */
+	public function validateData(&$data, $parameters){
+
+		if(!is_array($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] = $this->validateNumberValue($value);
+						break;
+					case 'checkbox':
+						$data[$name] = $this->validateCheckboxValue($value);
+						break;
+					case 'list':
+						$data[$name] = $this->validateListValue($value, $set[$name]['values']);
+						break;
+					default:
+					case 'text':
+						if(isset($set[$name]['pattern'])) {
+							$data[$name] = $this->validateTextValue($value, $set[$name]['pattern']);
+						} else {
+							$data[$name] = $this->validateTextValue($value);
+						}
+						break;
+					}
+
+					if(is_null($data[$name]) && isset($set[$name]['required']) && $set[$name]['required']) {
+						$this->addInvalidParameter($name, 'Parameter is invalid!');
+					}
+				}
+			}
+
+			if(!$registered) {
+				$this->addInvalidParameter($name, 'Parameter is not registered!');
+			}
+		}
+
+		return empty($this->invalid);
+	}
+}