API DataObject::validate() visibility changed to public (issue #1659)

DataObject::validate() is currently set to protected, but this means
you can't call validate() from outside the context of itself unless
you overload the method to use a public visibility and then call
parent::validate()

As it would turn out, most classes that overload this method already
set the visibility to public, so it would make sense the parent matches
that as well.

docs/en/changelogs/3.2.0.md

@@ -3,7 +3,24 @@
 ## Overview
 
  * Minimum PHP version raised to 5.3.3
+ * DataObject::validate() method visibility changed to public
 
 ## Changelog
 
-### Bugfixes
+### DataObject::validate() method visibility changed to public
+
+The visibility of `DataObject::validate()` has been changed from `protected` to `public`.
+
+Any existing classes that currently set this as `protected` should be changed like in
+this example:
+
+	::php
+	class MyDataClass extends DataObject {
+		...
+		public function validate() {
+			...
+		}
+		...
+	}
+
+### Bugfixes

model/DataObject.php

@@ -1015,7 +1015,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * 
 	 * @return A {@link ValidationResult} object
 	 */
-	protected function validate() {
+	public function validate() {
 		$result = ValidationResult::create();
 		$this->extend('validate', $result);
 		return $result;

security/PermissionRoleCode.php

@@ -14,7 +14,7 @@ class PermissionRoleCode extends DataObject {
 		"Role" => "PermissionRole",
 	);
 
-	protected function validate() {
+	public function validate() {
 		$result = parent::validate();
 
 		// Check that new code doesn't increase privileges, unless an admin is editing.

tests/model/DataObjectTest.php

@@ -1304,7 +1304,7 @@ class DataObjectTest_ValidatedObject extends DataObject implements TestOnly {
 		'Name' => 'Varchar(50)'
 	);
 	
-	protected function validate() {
+	public function validate() {
 		if(!empty($this->Name)) {
 			return new ValidationResult();
 		} else {