--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/exports/injector/HistoricalDischargeInjector.java	Wed Sep 10 10:01:11 2014 +0200
@@ -0,0 +1,47 @@
+package org.dive4elements.river.exports.injector;
+
+import org.apache.log4j.Logger;
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.artifacts.ContextInjector;
+import org.dive4elements.river.artifacts.D4EArtifact;
+import org.dive4elements.river.artifacts.access.HistoricalDischargeAccess;
+import org.dive4elements.river.artifacts.access.RangeAccess;
+import org.dive4elements.river.model.Gauge;
+import org.dive4elements.river.model.River;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import static org.dive4elements.river.exports.injector.InjectorConstants.CURRENT_KM;
+
+public class HistoricalDischargeInjector
+implements ContextInjector
+{
+    private static Logger log =
+        Logger.getLogger(HistoricalDischargeInjector.class);
+
+    @Override
+    public void setup(Element cfg) {
+
+    }
+
+    @Override
+    public void injectContext(
+        CallContext ctx,
+        Artifact artifact,
+        Document request
+    ) {
+        HistoricalDischargeAccess access =
+            new HistoricalDischargeAccess((D4EArtifact)artifact);
+        Long gaugeNumber = access.getOfficialGaugeNumber();
+        if (gaugeNumber == null) {
+            return;
+        }
+        Gauge gauge = Gauge.getGaugeByOfficialNumber(gaugeNumber);
+        if (gauge == null) {
+            return;
+        }
+        double km = gauge.getStation().doubleValue();
+        ctx.putContextValue(CURRENT_KM, km);
+    }
+}