initial commit of validation classes.

system/validation/rules/presence_of.php

@@ -0,0 +1,70 @@
+<?php namespace System\Validation\Rules;
+
+use System\Validation\Rule;
+
+class Presence_Of extends Rule {
+
+	/**
+	 * Indicates an empty string should be considered present.
+	 *
+	 * @var bool
+	 */
+	public $allow_empty = false;
+
+	/**
+	 * Indicates a null should be considered present.
+	 *
+	 * @var bool
+	 */
+	public $allow_null = false;
+
+	/**
+	 * Evaluate the validity of an attribute.
+	 *
+	 * @param  string  $attribute
+	 * @param  array   $attributes
+	 * @return void
+	 */
+	public function check($attribute, $attributes)
+	{
+		if ( ! array_key_exists($attribute, $attributes))
+		{
+			return false;
+		}
+
+		if (is_null($attributes[$attribute]) and ! $this->allow_null)
+		{
+			return false;
+		}
+
+		if (trim((string) $attributes[$attribute]) === '' and ! $this->allow_empty)
+		{
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Allow an empty string to be considered present.
+	 *
+	 * @return Presence_Of
+	 */
+	public function allow_empty()
+	{
+		$this->allow_empty = true;
+		return $this;
+	}
+
+	/**
+	 * Allow a null to be considered present.
+	 *
+	 * @return Presence_Of
+	 */
+	public function allow_null()
+	{
+		$this->allow_null = true;
+		return $this;
+	}
+
+}