If you allow users to export selected rows or if the toolbar is in compact mode, exportAll specifies the text of the command that exports all data.
In other cases, this option specifies the Export button's hint.
The text of the command that exports selected rows. Applies when allowExportSelectedData option is true.
The hint of the Export button when the allowExportSelectedData option is true.
When allowExportSelectedData is false, the exportAll text is used as the hint.