--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/CollectionMonitor.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,104 @@
+package org.dive4elements.river.artifacts;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.xml.xpath.XPathConstants;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.ArtifactNamespaceContext;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.artifacts.Hook;
+
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+import org.dive4elements.artifacts.common.utils.XMLUtils.ElementCreator;
+
+import org.dive4elements.artifactdatabase.state.Output;
+
+import org.dive4elements.river.artifacts.datacage.Recommendations;
+
+/** Monitors collection changes. */
+public class CollectionMonitor implements Hook {
+
+    public static final String XPATH_RESULT = "/art:result";
+
+
+    @Override
+    public void setup(Node cfg) {
+    }
+
+
+    @Override
+    public void execute(Artifact artifact, CallContext context, Document doc) {
+        FLYSArtifact flys = (FLYSArtifact) artifact;
+
+        Element result = (Element) XMLUtils.xpath(
+            doc,
+            XPATH_RESULT,
+            XPathConstants.NODE,
+            ArtifactNamespaceContext.INSTANCE);
+
+        ElementCreator creator = new ElementCreator(
+            doc,
+            ArtifactNamespaceContext.NAMESPACE_URI,
+            ArtifactNamespaceContext.NAMESPACE_PREFIX);
+
+        Element recommended = creator.create("recommended-artifacts");
+        result.appendChild(recommended);
+
+        String[] outs              = extractOutputNames(flys, context);
+        Map<String, Object> params = getNoneUserSpecificParameters(flys, context);
+
+        Recommendations rec = Recommendations.getInstance();
+
+        // TODO For newer official-lines recommendations we actually
+        // need user-id (null here).
+        rec.recommend(flys, null, outs, params, recommended);
+    }
+
+
+    /**
+     * Get outputnames from current state (only the ones for which
+     * facets exist).
+     */
+    public static String[] extractOutputNames(
+        FLYSArtifact flys,
+        CallContext  context)
+    {
+        if (flys instanceof ChartArtifact) {
+            return new String[0];
+        }
+
+        List<Output> outs = flys.getCurrentOutputs(context);
+
+        int num = outs == null ? 0 : outs.size();
+
+        String[] names = new String[num];
+
+        for (int i = 0; i < num; i++) {
+            names[i] = outs.get(i).getName();
+        }
+
+        return names;
+    }
+
+
+    /**
+     * Creates Map from Strings "recommended" to "true".
+     */
+    protected Map<String, Object> getNoneUserSpecificParameters(
+        FLYSArtifact flys,
+        CallContext  context)
+    {
+        Map<String, Object> params = new HashMap<String, Object>(1);
+        params.put("recommended", "true");
+
+        return params;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :