dropdown.settings.callbackDropDown element

getDropDown(id).settings.callback( command ) (since PennController 1.5)

or getDropDown(id).settings.callback( command1, command2 ) (since PennController 1.5)

Will execute the command(s) whenever an option is selected from the drop-down list.

Example:

newText("The weather is")
    .settings.after( newDropDown("temp","...").settings.add("cold","warm","hot") )
    .settings.after( newText("implicature", "implies that the weather is ...") )
    .print()
,
getDropDown("temp")
    .settings.callback(
        getDropDown("temp")
            .test.selected("warm").success( 
                getText("implicature").settings.text("implicates that the weather is not hot") 
            )
            .test.selected("hot").success( 
                getText("implicature").settings.text("implies that the weather is not cold") 
            )
            .test.selected("cold").success( 
                getText("implicature").settings.text("implies that the weather is not even warm") 
            )
    )

Prints The weather is … implies that the weather is … onto the page, where the first occurrence of is a drop-down list containing the options cold, warm and hot. Upon selection of the option, the continuation will be modified accordingly to the selected option.