--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/templating/StackFrames.java	Fri Nov 30 11:32:29 2012 +0100
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/templating/StackFrames.java	Thu Nov 29 11:48:20 2012 +0100
@@ -13,11 +13,17 @@
 
 import org.apache.log4j.Logger;
 
+
+/**
+ * Maintains stack of 'frames' which are maps from string to object.
+ * Used for variables in datacage/meta-data system.
+ */
 public class StackFrames
 implements   XPathVariableResolver
 {
     private static Logger log = Logger.getLogger(StackFrames.class);
 
+    /** The frames (used like a stack). */
     protected List<Map<String, Object>> frames;
 
     public StackFrames() {
@@ -31,14 +37,17 @@
         }
     }
 
+    /** Push a new String->Object map. */
     public void enter() {
         frames.add(new HashMap<String, Object>());
     }
 
+    /** Pop/Remove last String->Object map. */
     public void leave() {
         frames.remove(frames.size()-1);
     }
 
+    /** Put Key/Value in last String->Object map. */
     public void put(String key, Object value) {
         int N = frames.size();
         if (N > 0) {
@@ -46,6 +55,7 @@
         }
     }
 
+    /** Put multiple Key/Values in last String->Object map. */
     public void put(String [] keys, Object [] values) {
         Map<String, Object> top = frames.get(frames.size()-1);
         for (int i = 0; i < keys.length; ++i) {
@@ -53,6 +63,7 @@
         }
     }
 
+    /** Check last frame (string->object map) for key. */
     public boolean containsKey(String key) {
         key = key.toUpperCase();
         for (int i = frames.size()-1; i >= 0; --i) {
@@ -73,6 +84,8 @@
         return get(key, null);
     }
 
+    /** result[0] is modified with value when true returned.
+     * @return false if key not found in any frame. */
     public boolean getStore(String key, Object [] result) {
 
         key = key.toUpperCase();