APICHANGE: add validation extension hook to DataExtension

model/DataExtension.php

@@ -63,6 +63,15 @@ static function add_to_class($class, $extensionClass, $args = null) {
 	public static function unload_extra_statics($class, $extension) {
 		throw new Exception('unload_extra_statics gone');
 	}
+
+	/**
+	 * Hook for extension-specific validation.
+	 *
+	 * @param $validationResult Local validation result
+	 * @throws ValidationException
+	 */
+	function validate(ValidationResult &$validationResult) {
+	}
 
 	/**
 	 * Edit the given query object to support queries for this extension

model/DataObject.php

@@ -883,7 +883,7 @@ public function forceChange() {
 	 * Validate the current object.
 	 *
 	 * By default, there is no validation - objects are always valid!  However, you can overload this method in your
-	 * DataObject sub-classes to specify custom validation.
+	 * DataObject sub-classes to specify custom validation, or use the hook through DataExtension.
 	 * 
 	 * Invalid objects won't be able to be written - a warning will be thrown and no write will occur.  onBeforeWrite()
 	 * and onAfterWrite() won't get called either.
@@ -894,7 +894,9 @@ public function forceChange() {
 	 * @return A {@link ValidationResult} object
 	 */
 	protected function validate() {
-		return new ValidationResult();
+		$result = new ValidationResult();
+		$this->extend('validate', $result);
+		return $result;
 	}
 
 	/**