--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/injector/KmFromRequestInjector.java	Wed Oct 01 12:23:39 2014 +0200
@@ -0,0 +1,61 @@
+package org.dive4elements.river.exports.injector;
+
+import org.apache.log4j.Logger;
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.ArtifactNamespaceContext;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.artifacts.ContextInjector;
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+import org.dive4elements.river.artifacts.D4EArtifact;
+import org.dive4elements.river.artifacts.access.RangeAccess;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import static org.dive4elements.river.exports.injector.InjectorConstants.CURRENT_KM;
+
+
+public class KmFromRequestInjector
+implements ContextInjector
+{
+    private static final Logger log = Logger.getLogger(KmFromRequestInjector.class);
+
+    public static final Double INVALID_KM = Double.valueOf(-1d);
+    public static final String XPATH_CHART_CURRENTKM =
+        "/art:action/art:attributes/art:currentKm/@art:km";
+    @Override
+    public void setup(Element cfg) {
+
+    }
+
+    @Override
+    public void injectContext(
+        CallContext ctx,
+        Artifact artifact,
+        Document request) {
+        Double km = getCurrentKmFromRequest(request);
+        if (Double.isNaN(km)) {
+            RangeAccess access = new RangeAccess((D4EArtifact)artifact);
+            km = access.getFrom();
+        }
+        ctx.putContextValue(CURRENT_KM, km);
+    }
+
+    private Double getCurrentKmFromRequest(Document request) {
+
+        String km = XMLUtils.xpathString(
+            request,
+            XPATH_CHART_CURRENTKM,
+            ArtifactNamespaceContext.INSTANCE);
+
+        if (km == null) {
+            return Double.NaN;
+        }
+
+        try {
+            return Double.valueOf(km);
+        }
+        catch (NumberFormatException nfe) {
+            return Double.NaN;
+        }
+    }
+}