CheckAll
configurationWhen this options is set to true and checkboxes are enabled, a tristate checkbox appears above the embedded treeview. Clicking that checkbox will check or uncheck all the loaded enabled items of the treeview.
Note: when 'checkAll' is set to 'true' it is recommended that loadOnDemand is set to 'false' because otherwise checkAll may not interact with all subnodes of the treeview.
checkAll
BooleanDefault: false