enhanced validation, added mimes config array.

system/validation/nullable_rule.php

@@ -0,0 +1,94 @@
+<?php namespace System\Validation;
+
+use System\Str;
+
+abstract class Nullable_Rule extends Rule {
+
+	/**
+	 * Indicates an empty value should be considered valid.
+	 *
+	 * @var bool
+	 */
+	public $allow_empty = false;
+
+	/**
+	 * Indicates null should be considered valid.
+	 *
+	 * @var bool
+	 */
+	public $allow_null = false;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * If this method returns a value, the child class will return it
+	 * as the result of the validation. Otherwise, the child class will
+	 * continue validating as normal.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return mixed
+	 */
+	public function check($attribute, $attributes)
+	{
+		// -------------------------------------------------------------
+		// If the attribute doesn't exist, the child's validation
+		// check will be be halted, and a presence_of error will be
+		// raised if null is not allowed.
+		// -------------------------------------------------------------
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			if ( ! $this->allow_null)
+			{
+				$this->error = 'presence_of';
+			}
+
+			return is_null($this->error);
+		}
+
+		// -------------------------------------------------------------
+		// Make sure the attribute is not an empty string. An error
+		// will be raised if the attribute is empty and empty strings
+		// are not allowed, halting the child's validation.
+		// -------------------------------------------------------------
+		elseif (Str::length((string) $attributes[$attribute]) == 0 and ! $this->allow_empty)
+		{
+			$this->error = 'presence_of';
+
+			return false;
+		}
+	}
+
+	/**
+	 * Allow a empty and null to be considered valid.
+	 *
+	 * @return Nullable_Rule
+	 */
+	public function not_required()
+	{
+		return $this->allow_empty()->allow_null();
+	}
+
+	/**
+	 * Allow empty to be considered valid.
+	 *
+	 * @return Nullable_Rule
+	 */
+	public function allow_empty()
+	{
+		$this->allow_empty = true;
+		return $this;
+	}
+
+	/**
+	 * Allow null to be considered valid.
+	 *
+	 * @return Nullable_Rule
+	 */
+	public function allow_null()
+	{
+		$this->allow_null = true;
+		return $this;
+	}
+
+}