Likert scale with key press response?

[norabradford]

Hi, I'd like to use the likert scale plug-in but use the 1, 2, 3, 4 keys as a response instead of having the subject mouse click. Is this possible?
Thanks!

[ChristopheBossens]

You can add an event handler to the on_start function of the trial to handle keyboard events and select a radio button. But this will only work properly if you have a single rating scale on the screen. See example below:

var trial = {
        type: jsPsychSurveyLikert,
        questions: [
            {
            prompt: "I like vegetables.", 
            labels: [
                "Strongly Disagree", 
                "Disagree", 
                "Neutral", 
                "Agree", 
                "Strongly Agree"
            ]
            }
        ],
        on_start : function(){
            document.addEventListener("keypress", keyboardHandler);
        },
        on_finish: function(){
            document.removeEventListener("kepress", keyboardHandler);
        }
        };

        function keyboardHandler(e){
            if(!(e.code.includes("Digit") || e.code.includes("Numpad")))
                return;
            
            let digit = e.code.substr(e.code.length-1)-1;
            let radioButtons = document.getElementsByName('Q0');
            
            for(let idx = 0; idx < radioButtons.length; ++idx){
                if(radioButtons[idx].value == digit){
                    radioButtons[idx].checked = true;
                }
            }
        }