diff --git a/src/zutil/Timer.java b/src/zutil/Timer.java
index 2254d30..e0e29e5 100755
--- a/src/zutil/Timer.java
+++ b/src/zutil/Timer.java
@@ -27,6 +27,8 @@ package zutil;
 /**
  * This class is a timer, it will track time and
  * timeout after a specific amount of time.
+ * <br>
+ * Note that the {@link #start()} method needs to be called for the timer to start.
  *
  * Created by Ziver on 2015-07-15.
  */
@@ -37,6 +39,9 @@ public class Timer {
     private long timestamp;
 
 
+    /**
+     * Creates a new timer that in reset state.
+     */
     public Timer(long milisec){
         this.period = milisec;
         reset();
diff --git a/src/zutil/db/bean/DBBeanObjectDSO.java b/src/zutil/db/bean/DBBeanObjectDSO.java
index 9dd916e..3aa1733 100755
--- a/src/zutil/db/bean/DBBeanObjectDSO.java
+++ b/src/zutil/db/bean/DBBeanObjectDSO.java
@@ -48,7 +48,7 @@ public abstract class DBBeanObjectDSO<T> extends DBBean{
             }
 
             if (config != null && !config.isEmpty()) {
-                Configurator<T> configurator = new Configurator<>(cachedObj);
+                Configurator<T> configurator = getObjectConfigurator();
                 configurator.setValues(JSONParser.read(config));
                 configurator.applyConfiguration();
             }
@@ -60,7 +60,7 @@ public abstract class DBBeanObjectDSO<T> extends DBBean{
         if (cachedObj == null)
             this.config = null;
         else {
-            Configurator<T> configurator = new Configurator<>(cachedObj);
+            Configurator<T> configurator = getObjectConfigurator();
             this.config = JSONWriter.toString(configurator.getValuesAsNode());
         }
         super.save(db);
@@ -95,12 +95,16 @@ public abstract class DBBeanObjectDSO<T> extends DBBean{
         setObjectClass(clazz.getName());
     }
 
-    protected void setObjectClass(String clazz){
+    public void setObjectClass(String clazz){
         if (this.type == null || !this.type.equals(type)) {
+            // TODO: check if clazz is subclass of T
             setObject(null);
             this.type = clazz;
+            postUpdateAction(); // instantiate cached object
         }
     }
 
-
+    public Configurator<T> getObjectConfigurator(){
+        return new Configurator<>(cachedObj);
+    }
 }
diff --git a/src/zutil/ui/Configurator.java b/src/zutil/ui/Configurator.java
index 5681a73..77e14a7 100755
--- a/src/zutil/ui/Configurator.java
+++ b/src/zutil/ui/Configurator.java
@@ -47,6 +47,11 @@ import java.util.logging.Logger;
  * object the {@link Configurator#setValues(DataNode)} or {@link Configurator#setValues(Map)}
  * can be used to set the individual fields and finally call {@link Configurator#applyConfiguration()}
  * to configure the target object.
+ * <br />
+ * External listener can be registered to be called before or after configuration changes
+ * by implementing {@link PreConfigurationActionListener} or {@link PostConfigurationActionListener}.
+ * The configured object will autmatically be registered as a listener if it also implements
+ * these interfaces.
  *
  * <br>
  * Supported field types: String, int, boolean, enum
@@ -248,6 +253,7 @@ public class Configurator<T> {
 
             if     (f.getType() == String.class)    type = ConfigType.STRING;
             else if(f.getType() == int.class)       type = ConfigType.INT;
+            else if(f.getType() == double.class)    type = ConfigType.INT;
             else if(f.getType() == boolean.class)   type = ConfigType.BOOLEAN;
             else if(f.getType().isEnum())           type = ConfigType.ENUM;
             else
@@ -298,7 +304,11 @@ public class Configurator<T> {
                 case STRING:
                     value = v; break;
                 case INT:
-                    value = Integer.parseInt(v); break;
+                    if (field.getType() == double.class)
+                        value = Double.parseDouble(v);
+                    else
+                        value = Integer.parseInt(v);
+                    break;
                 case BOOLEAN:
                     value = Boolean.parseBoolean(v); break;
                 case ENUM: