--- a/ChangeLog	Thu Apr 28 10:27:27 2011 +0000
+++ b/ChangeLog	Thu Apr 28 10:30:30 2011 +0000
@@ -1,3 +1,14 @@
+2011-04-28  Ingo Weinzierl <ingo@intevation.de>
+
+	* artifact-database/src/main/java/de/intevation/artifactdatabase/transition/Transition.java:
+	  Modified the isValid() method. The transition needs to know about the
+	  current artifact where its data is stored, the current state and maybe
+	  the target state to determine if it is allowed to step from the current
+	  state to a target state!
+	  NOTE: This breaks the current API!
+
+artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java
+
 2011-04-28  Ingo Weinzierl <ingo@intevation.de>
 
 	* artifact-database/src/main/java/de/intevation/artifactdatabase/state/State.java,

--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/Transition.java	Thu Apr 28 10:27:27 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/Transition.java	Thu Apr 28 10:30:30 2011 +0000
@@ -1,5 +1,9 @@
 package de.intevation.artifactdatabase.transition;
 
+import org.w3c.dom.Node;
+
+import de.intevation.artifacts.Artifact;
+
 import de.intevation.artifactdatabase.state.State;
 
 
@@ -9,6 +13,13 @@
 public interface Transition {
 
     /**
+     * Initializes the transition.
+     *
+     * @param config The configuration node for the transition.
+     */
+    public void init(Node config);
+
+    /**
      * Return the ID of the start State.
      */
     public String getFrom();
@@ -33,8 +44,15 @@
     public void setTo(String to);
 
     /**
-     * Determines if the transition from <code>state</code> is valid.
+     * Determines if its valid to step from state <i>a</i> of an artifact
+     * <i>artifact</i> to state <i>b</i>.
+     *
+     * @param artifact The owner artifact of state a and b.
+     * @param a The current state.
+     * @param b The target state.
+     *
+     * @return true, if it is valid to step from a to b, otherwise false.
      */
-    public boolean isValid(State state);
+    public boolean isValid(Artifact artifact, State a, State b);
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

--- a/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java	Thu Apr 28 10:27:27 2011 +0000
+++ b/artifact-database/src/main/java/de/intevation/artifactdatabase/transition/TransitionEngine.java	Thu Apr 28 10:30:30 2011 +0000
@@ -7,6 +7,8 @@
 
 import org.apache.log4j.Logger;
 
+import de.intevation.artifacts.Artifact;
+
 import de.intevation.artifactdatabase.state.State;
 import de.intevation.artifactdatabase.state.StateEngine;
 
@@ -81,7 +83,10 @@
      *
      * @return a list of reachable states.
      */
-    public List<State> getReachableStates(State state, StateEngine engine) {
+    public List<State> getReachableStates(
+        Artifact    artifact,
+        State       state,
+        StateEngine engine) {
         List<Transition> transitions = getTransitions(state);
         List<State>      reachable   = new ArrayList<State>();
 
@@ -90,8 +95,10 @@
         }
 
         for (Transition t: transitions) {
-            if (t.isValid(state)) {
-                reachable.add(engine.getState(t.getTo()));
+            State target = engine.getState(t.getTo());
+
+            if (t.isValid(artifact, state, target)) {
+                reachable.add(target);
             }
         }
 
@@ -103,6 +110,7 @@
      * Determines if a state with a given identifier is reachable from a current
      * state.
      *
+     * @param artifact The owner artifact of state <i>state</i>.
      * @param targetId The identifier of the target state.
      * @param state The start state.
      * @param stateEngine The StateEngine.
@@ -110,11 +118,12 @@
      * @return true, if the target state is reachable, otherwise false.
      */
     public boolean isStateReachable(
+        Artifact    artifact,
         String      targetId,
         State       state,
         StateEngine stateEngine)
     {
-        List<State> reachable = getReachableStates(state, stateEngine);
+        List<State> reachable = getReachableStates(artifact, state,stateEngine);
 
         if (reachable == null || reachable.size() == 0) {
             return false;