NEW: PersistVisitor

ebean-api/src/main/java/io/ebean/DB.java

@@ -477,6 +477,19 @@ public final class DB {
   public static int saveAll(Object... beans) throws OptimisticLockException {
     return getDefault().saveAll(beans);
   }
+  
+  /**
+   * This will visit all beans in the persist graph on a given object
+   * <code>start</code>. It will call the visitor for each dirty bean that would
+   * be saved with {@link #save(Object)} or {@link #saveAll(Collection)}. You can
+   * use this method to implement custom validations.
+   * 
+   * @param start   could be a bean, a list of beans or a map of beans.
+   * @param visitor the visitor
+   */
+  public static void visitSave(Object start, PersistVisitor visitor) {
+    getDefault().visitSave(start, visitor);
+  }
 
   /**
    * This method checks the uniqueness of a bean. I.e. if the save will work. It will return the

ebean-api/src/main/java/io/ebean/Database.java

@@ -1017,6 +1017,17 @@ public interface Database {
    * Save all the beans.
    */
   int saveAll(Object... beans) throws OptimisticLockException;
+  
+  /**
+   * This will visit all beans in the persist graph on a given object
+   * <code>start</code>. It will call the visitor for each dirty bean that would
+   * be saved with {@link #save(Object)} or {@link #saveAll(Collection)}. You can
+   * use this method to implement custom validations.
+   * 
+   * @param start   could be a bean, a list of beans or a map of beans.
+   * @param visitor the visitor
+   */
+  void visitSave(Object start, PersistVisitor visitor);
 
   /**
    * Delete the bean.

ebean-api/src/main/java/io/ebean/PersistVisitor.java

@@ -0,0 +1,29 @@
+package io.ebean;
+
+import java.util.Collection;
+import java.util.Map;
+
+import io.ebean.bean.EntityBean;
+import io.ebean.plugin.Property;
+
+@FunctionalInterface
+public interface PersistVisitor {
+
+  PersistVisitor visitBean(EntityBean bean);
+
+  default PersistVisitor visitProperty(Property prop) {
+    return this;
+  };
+
+  default PersistVisitor visitCollection(Collection<?> collection) {
+    return this;
+  };
+
+  default PersistVisitor visitMap(Map<?, ?> map) {
+    return this;
+  };
+
+  default void visitEnd() {
+  }
+
+}