Toolbar Custom Action Button and Enable multiple selection
In order to add toolbar button, select checkbox Show toolbar action button.
Enter button text or define image Url.
Value <%VirtoCheckedItemsArray%> will be replaced with mass that contains keys and values of selected items.
In order return the default code, use Reset button.
Click Save when you have entered your code. Or use Cancel to cancel operation and close enter script editor window.
To allow selection of items, use checkbox Enable multiple selection
Every item will have a button that will make this item checked after clicking it (or unchecked, in case of second click)
The text of button has to be entered in the Action field. Tooltip can be entered in Description field. Tooltip will be displayed when pointing mouse on the button.
The quantity of selected items is shown on the toolbar.
In order to cancel the selection of items, use button (red cross icon) opposite Selected: field.