diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/src/layout/hierarchy.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/layout/hierarchy.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,120 @@
+d3.layout.hierarchy = function() {
+  var sort = d3_layout_hierarchySort,
+      children = d3_layout_hierarchyChildren,
+      value = d3_layout_hierarchyValue;
+
+  // Recursively compute the node depth and value.
+  // Also converts the data representation into a standard hierarchy structure.
+  function recurse(data, depth, nodes) {
+    var childs = children.call(hierarchy, data, depth),
+        node = d3_layout_hierarchyInline ? data : {data: data};
+    node.depth = depth;
+    nodes.push(node);
+    if (childs && (n = childs.length)) {
+      var i = -1,
+          n,
+          c = node.children = [],
+          v = 0,
+          j = depth + 1;
+      while (++i < n) {
+        d = recurse(childs[i], j, nodes);
+        d.parent = node;
+        c.push(d);
+        v += d.value;
+      }
+      if (sort) c.sort(sort);
+      if (value) node.value = v;
+    } else if (value) {
+      node.value = +value.call(hierarchy, data, depth) || 0;
+    }
+    return node;
+  }
+
+  // Recursively re-evaluates the node value.
+  function revalue(node, depth) {
+    var children = node.children,
+        v = 0;
+    if (children && (n = children.length)) {
+      var i = -1,
+          n,
+          j = depth + 1;
+      while (++i < n) v += revalue(children[i], j);
+    } else if (value) {
+      v = +value.call(hierarchy, d3_layout_hierarchyInline ? node : node.data, depth) || 0;
+    }
+    if (value) node.value = v;
+    return v;
+  }
+
+  function hierarchy(d) {
+    var nodes = [];
+    recurse(d, 0, nodes);
+    return nodes;
+  }
+
+  hierarchy.sort = function(x) {
+    if (!arguments.length) return sort;
+    sort = x;
+    return hierarchy;
+  };
+
+  hierarchy.children = function(x) {
+    if (!arguments.length) return children;
+    children = x;
+    return hierarchy;
+  };
+
+  hierarchy.value = function(x) {
+    if (!arguments.length) return value;
+    value = x;
+    return hierarchy;
+  };
+
+  // Re-evaluates the `value` property for the specified hierarchy.
+  hierarchy.revalue = function(root) {
+    revalue(root, 0);
+    return root;
+  };
+
+  return hierarchy;
+};
+
+// A method assignment helper for hierarchy subclasses.
+function d3_layout_hierarchyRebind(object, hierarchy) {
+  object.sort = d3.rebind(object, hierarchy.sort);
+  object.children = d3.rebind(object, hierarchy.children);
+  object.links = d3_layout_hierarchyLinks;
+  object.value = d3.rebind(object, hierarchy.value);
+
+  // If the new API is used, enabling inlining.
+  object.nodes = function(d) {
+    d3_layout_hierarchyInline = true;
+    return (object.nodes = object)(d);
+  };
+
+  return object;
+}
+
+function d3_layout_hierarchyChildren(d) {
+  return d.children;
+}
+
+function d3_layout_hierarchyValue(d) {
+  return d.value;
+}
+
+function d3_layout_hierarchySort(a, b) {
+  return b.value - a.value;
+}
+
+// Returns an array source+target objects for the specified nodes.
+function d3_layout_hierarchyLinks(nodes) {
+  return d3.merge(nodes.map(function(parent) {
+    return (parent.children || []).map(function(child) {
+      return {source: parent, target: child};
+    });
+  }));
+}
+
+// For backwards-compatibility, don't enable inlining by default.
+var d3_layout_hierarchyInline = false;