How to use dynamic trial parameters with the image-button-response plug-in?

[chester108]

Hello! I am creating a task in which participants are shown an image and decide to either press a button or not. Depending on if they press the button, they will be shown another image (stimuli A or stimuli B) drawn at random. I have the following code:

var button_pressed= [light_on1, light_on2, light_on3, light_on4, light_on5, light_on6, light_off1, light_off2, light_off3, light_off4]; //60% light on, 40% light off
var button_notpressed= [light_on7,light_on8,light_on9,light_on10,light_on11,light_on12,light_off5,light_off6,light_off7,light_off8]; 
var button_pressed_sample = jsPsych.randomization.sampleWithoutReplacement(button_pressed, 1); 
var button_notpressed_sample = jsPsych.randomization.sampleWithoutReplacement(button_notpressed, 1); 

var timeline= [];

var trial_one = {
    type: 'image-button-response',
    stimulus: light_off,
    choices: ['PRESS'],
    trial_duration: 3000,
    on_finish: function(data){
        if(data.key_press== 0){ // If 'PRESS' button clicked, then data.correct= true
        data.correct= true;
    } else {
        data.correct=false;
    }
}
}
var feedback_one = {
    type: "image-keyboard-response",
    trial_duration: 2000,
    stimulus:function(){
        var last_trial_correct=jsPsych.data.get().last(1).values()[0].correct;
        if (last_trial_correct){
            return jsPsych.randomization.sampleWithoutReplacement(button_pressed, 1); //Return 1 stimuli sampled from the randomized button pressed array without replacement
        } else {
            return jsPsych.randomization.sampleWithoutReplacement(button_notpressed, 1) //Return 1 stimuli sampled from the randomized button not pressed array without replacement
    }
    }
}
timeline.push(trial_one,feedback_one);

EDIT: the code above executes properly.
As of now, the code executes, but the stimuli are not being randomized in response to button press. Either all of the feedback stimuli are stimuli A or all are stimuli B. The code does not seem to be randomly sampling without replacement as I tried to indicate. The issue seems to be in the stimulus function under var feedback_one. Any help would be greatly appreciated!!

[chester108]

Solution: If you want a different image to be displayed each time, you'll need to replace the static variable with the jspsych.randomization call instead, to randomly select from the stimuli options each time. See code for edit.