While loop did not display text element as specified

[anjiecao]

Hello,

I'm trying to implement a while loop so that I can have a trial repeats until the participants satisfy the criteria. I'd like to have the participants be prompted when they did not meet the criterion. So far what I got is:

In my main HTML file:

 var while_loop_horizon_practice = {
        timeline: [trial_I_repeat], // this is the trial, it worked pretty fine on it own
        loop_function: function(){
            var data = jsPsych.data.get().last(1).values()[0];
            if(data.passed == false){ // the passed feature is set to "false" when the certain criteria are not met
                return true; // so the trial would remain in the loop
            } else {
                return false;
        }}
    }

And in my plugin file, the part where I found particularly buggy is when I deal with the end of the trial:

     if (num_in_frame == trial.stimuli.length ){ // this is where I checked whether it meets the criteria 
          trial_data.passed = true;
          display_element.innerHTML = '';
          jsPsych.pluginAPI.clearAllTimeouts();
          jsPsych.finishTrial(trial_data);   // this block works pretty fine with the for loop. It breaks the while loop and proceeds to the next trials 
      } else { // but this block doesn't work as expected
          trial_data.passed = false; // I set this to be false, so it stayed in the while loop forever 
          display_element.innerHTML = '??????';  // ideally this would give the participants a prompt, but this prompt never showed up 
         jsPsych.pluginAPI.setTimeout(jsPsych.finishTrial(trial_data),200); // I was hoping to achieve: showing the prompt 2s, then repeat the trial. But right now the prompt didn't show up, and it just repeated the trial

     }     

I wonder if I misunderstand the logic of terminating the trial or while loop. Any suggestion would be deeply appreciated!

[jodeleeuw]

In your else block there are two issues with the setTimeout method.

The first is that the first parameter to setTimeout should be function. At first glance it looks like you are passing a function, but you are actually calling the finishTrial() function and using the value of that function as the argument.

The second is that your timeout value is 200ms instead of 2,000ms.

Try this instead:

jsPsych.pluginAPI.setTimeout(function(){ jsPsych.finishTrial(trial_data) },2000); 

[anjiecao]

Ah I see, thanks a lot! I substituted this line, and now my text displayed and the trial ended in 2s. But now another bug is that this finishTrial seems to break my while loop as well. It does not repeat the trial, as the while loop's loop_function specifies. Do you have any idea why this might happen?

[jodeleeuw]

At first glance I don't see any issues here. Can you try using the debugger in the browser to see what the value of data.passed is in your while loop function?

[anjiecao]

Ah! never mind. I think it was probably a version thing. It works now. Thanks a lot!

[jodeleeuw]

Great! Glad it's fixed!