h:selectmanyListbox make “choose” option unselectable when at least one option is selected
Just add it as another <f:selectItem> and ask assistance of a bit of JavaScript to disable it when any value is selected during the change event. <h:selectManyListbox ... onchange="options[0].disabled=!!value"> <f:selectItem itemLabel="--choose--" itemValue="#{null}" /> <f:selectItems ... /> </h:selectManyListbox> The options[0] refers to the first option of the selection element. The !!value...