Button click processing

By default, any clicked button closes dialog. When a handler is assigned for the button, dialog behaviour depends on the returned value:

• true — dialog closes.
• false — blocking ("disabled") is removed from the button, dialog remains open.
• undefined (void) — no automatic actions performed, dialog closing and disabling removal must be performed manually.
• Promise — button switches to "loading" status. Resolved promise ("resolve") closes the dialog, rejected promise (reject) returns button to the initial state.

BX.UI.Dialogs.MessageBox.alert("Message", (messageBox, button, event) => 
{
    messageBox.close();
}
);

Handler arguments are the following:

• messageBox — dialog object (class instance BX.UI.Dialogs.MessageBox).
• button — button object (class instance BX.UI.Button).
• event — click event object (MouseEvent).