Slider response doesnt being recorded

[chen-goren]

Hi,

According to the "image-slider-response" (ver. 2.0.0.) documentation, I should get the user's choice for the slider's position in my data file. Yet, I don't get any values besides "slider_start". Therefore, I tried to manually add that value to my data file using:
"on_finish: function(data) { data.slider = data.response; } but i only get "null" values...
I would appreciate any help...

This is my code so far:

var imageDisplayTrial = {
type: jsPsychImageSliderResponse,
stimulus: function () {
var img = getRandomImage();
return img;
},
trial_duration: 5000,
post_trial_gap: 500,
stimulus_height: 400,
stimulus_width: 400,
labels: ['+', '-'],
prompt: "

Emotion

",
require_movement: false,
response_ends_trial: false,
min: 0,
max: 100,
slider_start: 50,
button_label: 'Continue', // This will be hidden via jQuery
on_load: function() {
$('.jspsych-btn').hide(); // Use jQuery to hide the button when the trial starts
},
data: {
task: 'image_display',
group: selectedGroup
},
on_finish: function(data) {
data.slider = data.response;
}
};

Thanks!

[Shaobin-Jiang]

This is expected behavior of the image-slider-response plugin, as the participant ought to submit their response via a button click and the absence of that button click indicates no response. In your case, you just have to make some tweaks from within on_load and on_finish.

In on_load, add this:

document.querySelector('#jspsych-image-slider-response-response').addEventListener('input', (event) => {
    window.slider_value = event.target.value;
});

Then in on_finish, do this:

data.slider = window.slider_value ?? data.slider_start;

[chen-goren]

Thank you very much Shaobin-Jiang, it worked!