Created a validation class to handle validation

Instead of making the Module the keeper of validation, moved the actual sanity checks to another class. This makes it stupid easy to use one module's validation (some or all) to validate arbitrary values elsewhere in your system.

classes/Validate.php

@@ -0,0 +1,157 @@
+<?php
+
+/**
+ * Validator
+ *
+ * PHP version 5
+ *
+ * Licensed under The MIT License
+ * Redistribution of these files must retain the above copyright notice.
+ *
+ * @author    Josh Sherman <pickles@joshtronic.com>
+ * @copyright Copyright 2007-2012, Josh Sherman
+ * @license   http://www.opensource.org/licenses/mit-license.html
+ * @package   PICKLES
+ * @link      https://github.com/joshtronic/pickles
+ */
+
+/**
+ * Validate Class
+ *
+ * Validation layer that's used by the Modules to validate passed data. Handles
+ * single sanity checks against a variable so the validation itself can be used
+ * in other places in the system
+ */
+class Validate
+{
+	/**
+	 * Is Valid?
+	 *
+	 * Checks if a variable is valid based on the passed rules.
+	 *
+	 * @param  mixed $value the value to be validated
+	 * @param  array $rules an array of rules (and messages) to validate with
+	 * @return mixed boolean true if valid, array of errors if invalid
+	 */
+	public static function isValid($value, $rules)
+	{
+		$errors = array();
+
+		if (is_array($rules))
+		{
+			foreach ($rules as $rule => $message)
+			{
+				$rule = explode(':', $rule);
+
+				switch (strtolower($rule[0]))
+				{
+					// @todo case 'alpha':
+					// @todo case 'alphanumeric':
+					// @todo case 'date':
+
+					// {{{ Checks using filter_var()
+
+					case 'filter':
+						if (count($rule) < 2)
+						{
+							throw new Exception('Invalid validation rule, expected: "validate:boolean|email|float|int|ip|regex|url".');
+						}
+						else
+						{
+							switch (strtolower($rule[1]))
+							{
+								case 'boolean':
+								case 'email':
+								case 'float':
+								case 'int':
+								case 'ip':
+								case 'regex':
+								case 'url':
+									$filter = constant('FILTER_VALIDATE_' . strtoupper($rule[1]));
+									break;
+
+								default:
+									throw new Exception('Invalid filter, expecting boolean, email, float, int, ip, regex or url.');
+									break;
+							}
+
+							if (!filter_var($value, $filter))
+							{
+								$errors[] = $message;
+							}
+						}
+
+						break;
+
+					// }}}
+					// {{{ Checks using strlen()
+
+					case 'length':
+						if (count($rule) < 3)
+						{
+							throw new Exception('Invalid validation rule, expected: "length:<|<=|==|!=|>=|>:integer".');
+						}
+						else
+						{
+							if (!filter_var($rule[2], FILTER_VALIDATE_INT))
+							{
+								throw new Exception('Invalid length value, expecting an integer.');
+							}
+							else
+							{
+								$length = strlen($value);
+
+								switch ($rule[1])
+								{
+									case '<':  $valid = $length <  $rule[2]; break;
+									case '<=': $valid = $length <= $rule[2]; break;
+									case '==': $valid = $length == $rule[2]; break;
+									case '!=': $valid = $length != $rule[2]; break;
+									case '>=': $valid = $length >= $rule[2]; break;
+									case '>':  $valid = $length >  $rule[2]; break;
+
+									default:
+										throw new Exception('Invalid operator, expecting <, <=, ==, !=, >= or >.');
+										break;
+								}
+
+								if ($valid === true)
+								{
+									$errors[] = $message;
+								}
+							}
+						}
+
+						break;
+
+					// }}}
+
+					// @todo case 'range':
+
+					// {{{ Checks using preg_match()
+
+					case 'regex':
+						if (count($rule) < 3)
+						{
+							throw new Exception('Invalid validation rule, expected: "regex:is|not:string".');
+						}
+						else
+						{
+							if ((strtolower($rule[1]) == 'not' && !preg_match($rule[2], $value)) || preg_match($rule[2], $value))
+							{
+								$errors[] = $message;
+							}
+						}
+						break;
+
+					// }}}
+				}
+
+			}
+		}
+
+		return count($errors) ? $errors : true;
+	}
+}
+
+?>