beforeShow

fires before a control is shown

beforeShow: (value: ICheckboxGroupValue) => boolean | void;

Parameters:

value: object - the current value of the control. The object contains a set of key:value pairs where key is the id of a checkbox and value is the value/state of the checkbox.

Returns:

Return false to prevent a control from being shown; otherwise, true.

Example

form.getItem("CheckboxGroup").events.on("BeforeShow", function(value) {    console.log("BeforeShow", value);    return true;});