diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/src/core/selection-data.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/core/selection-data.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,110 @@
+// TODO data(null) for clearing data?
+d3_selectionPrototype.data = function(data, join) {
+  var enter = [],
+      update = [],
+      exit = [];
+
+  function bind(group, groupData) {
+    var i,
+        n = group.length,
+        m = groupData.length,
+        n0 = Math.min(n, m),
+        n1 = Math.max(n, m),
+        updateNodes = [],
+        enterNodes = [],
+        exitNodes = [],
+        node,
+        nodeData;
+
+    if (join) {
+      var nodeByKey = {},
+          keys = [],
+          key,
+          j = groupData.length;
+
+      for (i = -1; ++i < n;) {
+        key = join.call(node = group[i], node.__data__, i);
+        if (key in nodeByKey) {
+          exitNodes[j++] = node; // duplicate key
+        } else {
+          nodeByKey[key] = node;
+        }
+        keys.push(key);
+      }
+
+      for (i = -1; ++i < m;) {
+        node = nodeByKey[key = join.call(groupData, nodeData = groupData[i], i)];
+        if (node) {
+          node.__data__ = nodeData;
+          updateNodes[i] = node;
+          enterNodes[i] = exitNodes[i] = null;
+        } else {
+          enterNodes[i] = d3_selection_dataNode(nodeData);
+          updateNodes[i] = exitNodes[i] = null;
+        }
+        delete nodeByKey[key];
+      }
+
+      for (i = -1; ++i < n;) {
+        if (keys[i] in nodeByKey) {
+          exitNodes[i] = group[i];
+        }
+      }
+    } else {
+      for (i = -1; ++i < n0;) {
+        node = group[i];
+        nodeData = groupData[i];
+        if (node) {
+          node.__data__ = nodeData;
+          updateNodes[i] = node;
+          enterNodes[i] = exitNodes[i] = null;
+        } else {
+          enterNodes[i] = d3_selection_dataNode(nodeData);
+          updateNodes[i] = exitNodes[i] = null;
+        }
+      }
+      for (; i < m; ++i) {
+        enterNodes[i] = d3_selection_dataNode(groupData[i]);
+        updateNodes[i] = exitNodes[i] = null;
+      }
+      for (; i < n1; ++i) {
+        exitNodes[i] = group[i];
+        enterNodes[i] = updateNodes[i] = null;
+      }
+    }
+
+    enterNodes.update
+        = updateNodes;
+
+    enterNodes.parentNode
+        = updateNodes.parentNode
+        = exitNodes.parentNode
+        = group.parentNode;
+
+    enter.push(enterNodes);
+    update.push(updateNodes);
+    exit.push(exitNodes);
+  }
+
+  var i = -1,
+      n = this.length,
+      group;
+  if (typeof data === "function") {
+    while (++i < n) {
+      bind(group = this[i], data.call(group, group.parentNode.__data__, i));
+    }
+  } else {
+    while (++i < n) {
+      bind(group = this[i], data);
+    }
+  }
+
+  var selection = d3_selection(update);
+  selection.enter = function() { return d3_selection_enter(enter); };
+  selection.exit = function() { return d3_selection(exit); };
+  return selection;
+};
+
+function d3_selection_dataNode(data) {
+  return {__data__: data};
+}