### Tracking Changes

Wijmo's CollectionView class can keep track of changes made to the data. This feature is useful in situations where you must submit changes to the server. To turn on change tracking, set the trackChanges property to true. Once you do that, the CollectionView keeps track of any changes made to the data and exposes them in three arrays:

- itemsEdited: This list contains items that are edited using the beginEdit and commitEdit methods.
- itemsAdded: This list contains items that are added using the addNew and commitNew methods.
- itemsRemoved: This list contains items that are removed using the remove method.

This feature is demonstrated below using a FlexGrid. The grid is bound to a CollectionView with trackChanges set to true. As you edit the grid, the changes are shown in three grids below.

#### Change the data here:

#### See the changes here

##### Items Edited ({{data.itemsEdited.length}} items)

##### Items Added ({{data.itemsAdded.length}} items)

##### Items Removed ({{data.itemsRemoved.length}} items)