beforeShow

fires before a Container control is shown

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

Parameters:

value: undefined - the current value of the control, null

Returns:

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

Example

form.getItem("container").events.on("beforeShow", function(text) {
    console.log("beforeShow", text);
    return true;
});

Change log:

added in v7.2