--- a/artifacts/src/main/java/org/dive4elements/river/exports/DiagramAttributes.java	Thu Sep 26 11:41:02 2013 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/DiagramAttributes.java	Thu Sep 26 12:56:37 2013 +0200
@@ -110,9 +110,9 @@
 
     public static class AxisAttributes {
         private String  name;
-        private boolean isLeftAlign;
-        private boolean forceAlign;
-        private boolean includeZero;
+        private boolean isLeftAlign; // TODO: Remove!
+        private boolean forceAlign;  // TODO: Remove!
+        private boolean includeZero; // TODO: Use Evaluator
 
         private Evaluator isInverted;
 
@@ -205,54 +205,95 @@
 
     } // class AxisProcessor
 
-    public static class Argument {
-        private String expression;
-        private String type;
+    public abstract static class ConvertEvaluator
+    implements Evaluator
+    {
+        protected String key;
+        protected String type;
 
-        public Argument() {
+        public ConvertEvaluator() {
         }
 
-        public Argument(String expression, String type) {
-            this.expression = expression;
+        public ConvertEvaluator(String key, String type) {
+            this.key  = key;
             this.type = type;
         }
 
-        public Object evaluate(D4EArtifact artifact, CallContext context) {
-            if (expression.startsWith("artifact.")) {
-                String value = artifact.getDataAsString(
-                    expression.substring("artifact.".length()));
-                return convert(value);
+        protected Object convert(Object value) {
+            if (value == null || type == null || type.isEmpty()) {
+                return value;
             }
-            if (expression.startsWith("context.")) {
-                return context.getContextValue(
-                    expression.substring("context.".length()));
+            if (value instanceof String) {
+                String v = (String)value;
+                if ("double".equals(type)) {
+                    return Double.valueOf(v);
+                }
+                if ("int".equals(type)) {
+                    return Integer.valueOf(v);
+                }
+                if ("string".equals(type)) {
+                    return v;
+                }
             }
-            return expression;
+            // TODO: Support more types
+            return value;
+        }
+    } // class ConvertEvaluator
+
+    public static class ContextEvaluator extends ConvertEvaluator {
+
+        public ContextEvaluator() {
         }
 
-        private Object convert(String value) {
-            if (value == null || type == null) {
-                return value;
-            }
-            if ("double".equals(type)) {
-                return Double.valueOf(value);
-            }
-            if ("int".equals(type)) {
-                return Integer.valueOf(value);
-            }
-            // TODO: more types
+        public ContextEvaluator(String key, String type) {
+            super(key, type);
+        }
+
+        @Override
+        public Object evaluate(D4EArtifact artifact, CallContext context) {
+            return convert(context.getContextValue(key));
+        }
+    } // class ContextEvaluator
+
+    public static class ArtifactEvaluator extends ConvertEvaluator {
+
+        public ArtifactEvaluator() {
+        }
+
+        public ArtifactEvaluator(String key, String type) {
+            super(key, type);
+        }
+
+        @Override
+        public Object evaluate(D4EArtifact artifact, CallContext context) {
+            return convert(artifact.getDataAsString(key));
+        }
+    } // class ContextEvaluator
+
+    public static class StringEvaluator implements Evaluator {
+
+        private String value;
+
+        public StringEvaluator() {
+        }
+        public StringEvaluator(String value) {
+            this.value = value;
+        }
+
+        @Override
+        public Object evaluate(D4EArtifact artifact, CallContext context) {
             return value;
         }
-    } // class Argument
+    } // class StringEvaluator
 
     public static class Title {
 
         private String key;
         private String def;
-        private List<Argument> arguments;
+        private List<Evaluator> arguments;
 
         public Title() {
-            arguments = new ArrayList<Argument>(5);
+            arguments = new ArrayList<Evaluator>(5);
         }
 
         public Title(String key) {
@@ -269,7 +310,7 @@
             return key;
         }
 
-        public void addArgument(Argument argument) {
+        public void addArgument(Evaluator argument) {
             arguments.add(argument);
         }
 
@@ -345,25 +386,34 @@
         }
     }
 
-    private Evaluator parseEvaluator(String s, Evaluator def) {
+    private static Evaluator createDynamicEvaluator(
+        String    className,
+        Evaluator def
+    ) {
+        try {
+            Class<Evaluator> clazz = (Class<Evaluator>)Class.forName(className);
+            return clazz.newInstance();
+        }
+        catch (ClassNotFoundException cnfe) {
+            log.error(cnfe, cnfe);
+        }
+        catch (InstantiationException ie) {
+            log.error(ie, ie);
+        }
+        catch (IllegalAccessException iae) {
+            log.error(iae, iae);
+        }
+        return def;
+    }
+
+    private static Evaluator parseEvaluator(String s, Evaluator def) {
         if ((s = s.trim()).isEmpty()) return def;
         if ("true".equals(s)) return TRUE;
         if ("false".equals(s)) return FALSE;
         if (s.endsWith("()")) {
-            s = s.substring(0, s.length()-2).trim();
-            try {
-                Class<Evaluator> clazz = (Class<Evaluator>)Class.forName(s);
-                return clazz.newInstance();
-            }
-            catch (ClassNotFoundException cnfe) {
-                log.error(cnfe, cnfe);
-            }
-            catch (InstantiationException ie) {
-                log.error(ie, ie);
-            }
-            catch (IllegalAccessException iae) {
-                log.error(iae, iae);
-            }
+            return createDynamicEvaluator(
+                s.substring(0, s.length()-2).trim(),
+                def);
         }
         return def;
     }
@@ -423,7 +473,7 @@
             "X",
             false,
             false,
-            false,
+            includeZero.equals("true"),
             parseEvaluator(isInverted, FALSE),
             title);
     }
@@ -442,7 +492,24 @@
             Element argumentElement = (Element)argumentNodes.item(i);
             String expression = argumentElement.getAttribute("expr");
             String type = argumentElement.getAttribute("type");
-            title.addArgument(new Argument(expression, type));
+
+            Evaluator ev = new StringEvaluator(expression);
+
+            if (expression.endsWith("()")) {
+                ev = createDynamicEvaluator(
+                    expression.substring(0, expression.length()-2).trim(),
+                    ev);
+            }
+            else if (expression.startsWith("artifact.")) {
+                ev = new ArtifactEvaluator(
+                    expression.substring("artifact.".length()), type);
+            }
+            else if (expression.startsWith("context.")) {
+                ev = new ContextEvaluator(
+                    expression.substring("context.".length()), type);
+            }
+
+            title.addArgument(ev);
         }
         return title;
     }