--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/templating/StackFrames.java	Mon Aug 01 08:31:09 2011 +0000
@@ -0,0 +1,87 @@
+package de.intevation.flys.artifacts.datacage.templating;
+
+import java.util.Map;
+import java.util.List;
+import java.util.HashMap;
+import java.util.ArrayList;
+
+import javax.xml.xpath.XPathVariableResolver;
+
+import javax.xml.namespace.QName;
+
+import org.apache.log4j.Logger;
+
+public class StackFrames
+implements   XPathVariableResolver
+{
+    private static Logger log = Logger.getLogger(StackFrames.class);
+
+    protected List<Map<String, Object>> frames;
+
+    public StackFrames() {
+        frames = new ArrayList<Map<String, Object>>();
+    }
+
+    public StackFrames(Map<String, Object> initialFrame) {
+        this();
+        if (initialFrame != null) {
+            frames.add(new HashMap<String, Object>(initialFrame));
+        }
+    }
+
+    public void enter() {
+        frames.add(new HashMap<String, Object>());
+    }
+
+    public void leave() {
+        frames.remove(frames.size()-1);
+    }
+
+    public void put(String key, Object value) {
+        int N = frames.size();
+        if (N > 0) {
+            frames.get(N-1).put(key, value);
+        }
+    }
+
+    public void put(String [] keys, Object [] values) {
+        Map<String, Object> top = frames.get(frames.size()-1);
+        for (int i = 0; i < keys.length; ++i) {
+            top.put(keys[i], values[i]);
+        }
+    }
+
+    public boolean containsKey(String key) {
+        for (int i = frames.size()-1; i >= 0; --i) {
+            if (frames.get(i).containsKey(key)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public Object get(String key) {
+        return get(key, null);
+    }
+
+    public Object get(String key, Object def) {
+
+        for (int i = frames.size()-1; i >= 0; --i) {
+            Map<String, Object> frame = frames.get(i);
+            if (frame.containsKey(key)) {
+                return frame.get(key);
+            }
+        }
+
+        return def;
+    }
+
+    @Override
+    public Object resolveVariable(QName variableName) {
+        if (log.isDebugEnabled()) {
+            log.debug("resolve var: " + variableName);
+        }
+        return get(variableName.getLocalPart());
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :