Use enum instead of boolean

Author: codeconsole

grails-datastore-gorm-test/src/test/groovy/org/grails/datastore/gorm/CustomAutoTimestampSpec.groovy

@@ -1,6 +1,7 @@
 package org.grails.datastore.gorm
 
 import grails.gorm.annotation.AutoTimestamp
+import static grails.gorm.annotation.AutoTimestamp.EventType.*;
 import grails.gorm.tests.GormDatastoreSpec
 import grails.persistence.Entity
 
@@ -39,6 +40,6 @@ class CustomAutoTimestampSpec extends GormDatastoreSpec {
 class RecordCustom {
     Long id
     String name
-    @AutoTimestamp(false) Date created
+    @AutoTimestamp(ON_INSERT) Date created
     @AutoTimestamp Date modified
 }

grails-datastore-gorm/src/main/groovy/grails/gorm/annotation/AutoTimestamp.java

@@ -30,9 +30,17 @@
 @Retention(RetentionPolicy.RUNTIME)
 @Target({ElementType.FIELD})
 public @interface AutoTimestamp {
+
+    /**
+     * Enum to specify when auto-timestamping should occur.
+     */
+    enum EventType {
+        ON_INSERT,
+        ON_UPDATE
+    }
+
     /**
-     * Whether to include auto-timestamping on update events.
-     * Setting value to false only performs auto-timestamping on insert events.
+     * When to apply auto-timestamping
      */
-    boolean value() default true;
+    EventType value() default EventType.ON_UPDATE;
 }

grails-datastore-gorm/src/main/groovy/org/grails/datastore/gorm/events/AutoTimestampEventListener.java

@@ -170,7 +170,7 @@ protected void storeDateCreatedAndLastUpdatedInfo(PersistentEntity persistentEnt
                         Field field = getFieldFromHierarchy(persistentEntity, property.getName());
                         if (field != null && field.isAnnotationPresent(AutoTimestamp.class)) {
                             AutoTimestamp autoTimestamp = field.getAnnotation(AutoTimestamp.class);
-                            if (autoTimestamp.value()) {
+                            if (autoTimestamp.value() == AutoTimestamp.EventType.ON_UPDATE) {
                                 storeTimestampAvailability(entitiesWithLastUpdated, persistentEntity, property);
                             } else {
                                 storeTimestampAvailability(entitiesWithDateCreated, persistentEntity, property);