Add type check to prevent errors related to Hash::get()

Fixes #3041

lib/Cake/View/Helper.php

@@ -691,7 +691,7 @@ public function value($options = array(), $field = null, $key = 'value') {
 		$data = $this->request->data;
 
 		$entity = $this->entity();
-		if (!empty($data) && !empty($entity)) {
+		if (!empty($data) && is_array($data) && !empty($entity)) {
 			$result = Hash::get($data, implode('.', $entity));
 		}