Updates DataSet and DataView remove event payload (#2189)

* Updates all 'remove' events in DataSet and DataView to include the objects that were removed in addition to the the ids.
* Updated the documentation to reflect changes.
* Fixed possible object mutation when typeof id is object in DataSet.remove.

docs/data/dataset.html

@@ -598,9 +598,11 @@ function (event, properties, senderId) {
         <code>update</code>, and <code>remove</code>,
         <code>properties</code> is always an object containing a property
         <code>items</code>, which contains an array with the ids of the affected
-        items. The <code>update</code> event has an extra field <code>oldData</code>
-        containing the original data of the updated items, and a field <code>data</code>
-        containing the changes: the properties of the items that are being updated.
+        items. The <code>update</code> and <code>remove</code> events have an extra
+        field <code>oldData</code> containing the original data of the items in the
+        dataset before the items were updated or removed. The <code>update</code>
+        event also contains a field <code>data</code> containing the changes:
+        the properties of the items that are being updated. 
       </td>
     </tr>
     <tr>

lib/DataSet.js

@@ -668,25 +668,26 @@ DataSet.prototype._sort = function (items, order) {
  */
 DataSet.prototype.remove = function (id, senderId) {
   var removedIds = [],
-      i, len, removedId;
-
-  if (Array.isArray(id)) {
-    for (i = 0, len = id.length; i < len; i++) {
-      removedId = this._remove(id[i]);
-      if (removedId != null) {
-        removedIds.push(removedId);
+      removedItems = [],
+      ids = [],
+      i, len, itemId, item;
+
+  // force everything to be an array for simplicity
+  ids = Array.isArray(id) ? id : [id];
+
+  for (i = 0, len = ids.length; i < len; i++) {
+    item = this._remove(ids[i]);
+    if (item) {
+      itemId = item[this._fieldId];
+      if (itemId) {
+        removedIds.push(itemId);
+        removedItems.push(item);
       }
     }
   }
-  else {
-    removedId = this._remove(id);
-    if (removedId != null) {
-      removedIds.push(removedId);
-    }
-  }
 
   if (removedIds.length) {
-    this._trigger('remove', {items: removedIds}, senderId);
+    this._trigger('remove', {items: removedIds, oldData: removedItems}, senderId);
   }
 
   return removedIds;
@@ -699,20 +700,23 @@ DataSet.prototype.remove = function (id, senderId) {
  * @private
  */
 DataSet.prototype._remove = function (id) {
+  var item,
+      ident;
+
+  // confirm the id to use based on the args type
   if (util.isNumber(id) || util.isString(id)) {
-    if (this._data[id]) {
-      delete this._data[id];
-      this.length--;
-      return id;
-    }
+    ident = id;
   }
   else if (id instanceof Object) {
-    var itemId = id[this._fieldId];
-    if (itemId !== undefined && this._data[itemId]) {
-      delete this._data[itemId];
-      this.length--;
-      return itemId;
-    }
+    ident = id[this._fieldId]; // look for the identifier field using _fieldId
+  }
+
+  // do the remove if the item is found
+  if (ident !== undefined && this._data[ident]) {
+    item = this._data[ident];
+    delete this._data[ident];
+    this.length--;
+    return item;
   }
   return null;
 };
@@ -723,12 +727,18 @@ DataSet.prototype._remove = function (id) {
  * @return {Array} removedIds    The ids of all removed items
  */
 DataSet.prototype.clear = function (senderId) {
+  var i, len;
   var ids = Object.keys(this._data);
+  var items = [];
+  
+  for (i = 0, len = ids.length; i < len; i++) {
+    items.push(this._data[ids[i]]);
+  }
 
   this._data = {};
   this.length = 0;
 
-  this._trigger('remove', {items: ids}, senderId);
+  this._trigger('remove', {items: ids, oldData: items}, senderId);
 
   return ids;
 };

lib/DataView.js

@@ -35,7 +35,7 @@ function DataView (data, options) {
  * @param {DataSet | DataView} data
  */
 DataView.prototype.setData = function (data) {
-  var ids, id, i, len;
+  var ids, id, i, len, items;
 
   if (this._data) {
     // unsubscribe from current dataset
@@ -44,10 +44,16 @@ DataView.prototype.setData = function (data) {
     }
 
     // trigger a remove of all items in memory
-    ids = Object.keys(this._ids);
+    ids = this._data.getIds({filter: this._options && this._options.filter});
+    items = [];
+
+    for (i = 0, len = ids.length; i < len; i++) {
+      items.push(this._data._data[ids[i]]);
+    }
+
     this._ids = {};
     this.length = 0;
-    this._trigger('remove', {items: ids});
+    this._trigger('remove', {items: ids, oldData: items});
   }
 
   this._data = data;
@@ -80,18 +86,19 @@ DataView.prototype.setData = function (data) {
  */
 DataView.prototype.refresh = function () {
   var id, i, len;
-  var ids = this._data.getIds({filter: this._options && this._options.filter});
-  var oldIds = Object.keys(this._ids);
-  var newIds = {};
-  var added = [];
-  var removed = [];
+  var ids = this._data.getIds({filter: this._options && this._options.filter}),
+      oldIds = Object.keys(this._ids),
+      newIds = {},
+      addedIds = [],
+      removedIds = [],
+      removedItems = [];
 
   // check for additions
   for (i = 0, len = ids.length; i < len; i++) {
     id = ids[i];
     newIds[id] = true;
     if (!this._ids[id]) {
-      added.push(id);
+      addedIds.push(id);
       this._ids[id] = true;
     }
   }
@@ -100,19 +107,20 @@ DataView.prototype.refresh = function () {
   for (i = 0, len = oldIds.length; i < len; i++) {
     id = oldIds[i];
     if (!newIds[id]) {
-      removed.push(id);
+      removedIds.push(id);
+      removedItems.push(this._data[id]);
       delete this._ids[id];
     }
   }
 
-  this.length += added.length - removed.length;
+  this.length += addedIds.length - removedIds.length;
 
   // trigger events
-  if (added.length) {
+  if (addedIds.length) {
     this._trigger('add', {items: added});
   }
-  if (removed.length) {
-    this._trigger('remove', {items: removed});
+  if (removedIds.length) {
+    this._trigger('remove', {items: removedIds, oldData: removedItems});
   }
 };
 
@@ -298,14 +306,14 @@ DataView.prototype.getDataSet = function () {
 DataView.prototype._onEvent = function (event, params, senderId) {
   var i, len, id, item;
   var ids = params && params.items;
-  var data = this._data;
-  var updatedData = [];
-  var oldData = [];
-  var added = [];
-  var updated = [];
-  var removed = [];
-
-  if (ids && data) {
+  var addedIds = [],
+      updatedIds = [],
+      removedIds = [],
+      oldItems = [],
+      updatedItems = [],
+      removedItems = [];
+
+  if (ids && this._data) {
     switch (event) {
       case 'add':
         // filter the ids of the added items
@@ -314,7 +322,7 @@ DataView.prototype._onEvent = function (event, params, senderId) {
           item = this.get(id);
           if (item) {
             this._ids[id] = true;
-            added.push(id);
+            addedIds.push(id);
           }
         }
 
@@ -329,19 +337,20 @@ DataView.prototype._onEvent = function (event, params, senderId) {
 
           if (item) {
             if (this._ids[id]) {
-              updated.push(id);
-              updatedData.push(params.data[i]);
-              oldData.push(params.oldData[i]);
+              updatedIds.push(id);
+              updatedItems.push(params.data[i]);
+              oldItems.push(params.oldData[i]);
             }
             else {
               this._ids[id] = true;
-              added.push(id);
+              addedIds.push(id);
             }
           }
           else {
             if (this._ids[id]) {
               delete this._ids[id];
-              removed.push(id);
+              removedIds.push(id);
+              removedItems.push(params.oldData[i]);
             }
             else {
               // nothing interesting for me :-(
@@ -357,23 +366,24 @@ DataView.prototype._onEvent = function (event, params, senderId) {
           id = ids[i];
           if (this._ids[id]) {
             delete this._ids[id];
-            removed.push(id);
+            removedIds.push(id);
+            removedItems.push(params.oldData[i]);
           }
         }
 
         break;
     }
 
-    this.length += added.length - removed.length;
+    this.length += addedIds.length - removedIds.length;
 
-    if (added.length) {
-      this._trigger('add', {items: added}, senderId);
+    if (addedIds.length) {
+      this._trigger('add', {items: addedIds}, senderId);
     }
-    if (updated.length) {
-      this._trigger('update', {items: updated, oldData: oldData, data: updatedData}, senderId);
+    if (updatedIds.length) {
+      this._trigger('update', {items: updatedIds, oldData: oldItems, data: updatedItems}, senderId);
     }
-    if (removed.length) {
-      this._trigger('remove', {items: removed}, senderId);
+    if (removedIds.length) {
+      this._trigger('remove', {items: removedIds, oldData: removedItems}, senderId);
     }
   }
 };