Uncaught TypeError: Cannot read property 'data' of undefined

Comments

• Sami

  April 2020

  I fixed the previous error. Now this error appears:

  Uncaught TypeError: Cannot read property 'body' of null

  I would be grateful if sombody can help me.

  
  

  Thanks,

  Sami

  2.JPG

  
  
• Daniel

  April 2020

  Hi @Sami,

  Your output suggests you are not running your experiment online but in regular OpenSesame. The error messages you are reporting are common for Python (which is used by OpenSesame) and not for JavaScript (which is used for the web).

  My impressions is that your experiment is not working as it should yet, even in OpenSesame. Am I right? If you first try to get it running in there, then there is a bigger chance that it will also run without problems online.

  The second screenshot you post is from an online experiment but it is hard to say why this error occurs. My guess is that you are using an inline script item, which is not supported yet, or have an incorrect statement somewhere else (for example in a run if field).

  
• Sami

  April 2020

  Hi Daniel,

  Thank you very much for your response.

  My experiment runs nicely when I use the quick run, but it faces errors when I run it in the OSweb.

  DPT_keyboard-pic inst.osexp

  Could you please look at my experiment?

  (I use the left and right arrows for responsing).

  
  

  Thanks,

  Sami
• Daniel

  April 2020

  Hi Sami,

  Right after opening your experiment, I immediately get the error:

  

  Osweb only supports a limited set of modules and matplotlib certainly isn't one of them! Please check your experiment. you *cannot* use any inline_script items containing Python code. If you want to use inline scripting, you need to use the inline_javascript items, but what you can do with these is also very limited at the moment.

  
• Sami

  April 2020

  Hi Daniel,

  Thanks again for your help. In your idea, is there any way to fix the problem? I am not familiar with JavaScript, and I don't know what should I do?
• Daniel

  April 2020

  Hi @Sami,

  I have to apologize as the previous error that I experienced with your experiment and that I reported here was actually due to a fault in my OpenSesame installation. I managed to open your experiment correctly now, and it's actually very well built en completely compatible with osweb.

  I don't know what causes your error, but I did prevent it by fixing some inconsistencies that are hard to notice if you just start working with OpenSesame/osweb, but nevertheless very important:

  1. in the keyboard_response item you set the allowed responses as left; right . Try and remove the space after ; so it reads left;right
  2. In the run if fields of the trial_sequence item, you write down conditions as =vars.correct == 1 while this should technically work, there is an easier way to do comparisons with variables in OpenSesame by using [] ; you can write this condition also as [correct] = 1 . OpenSesame (and osweb) will automatically look in the vars object for the variable name that you put between these brackets.

  Once I made these changes your experiment ran nicely in osweb. The only thing that still seemed off was the feedback (the smiley) after a response, which appeared onscreen for too short a time.

  I hope this helps you getting things running!

  
• Sami

  April 2020

  Dear Daniel,

  I can't thank you enough. I made the changes that you had proposed and it worked nicely. I also changed and corrected the duration of the feedback.

  I faced another problem in the "feedback item" in OSweb. average reaction time (avg_rt) and accuracy percent (acc)% were not seen in the feedback item at the end of practice.
• Sami

  April 2020

  It was my first experience with open sesame, and I am so happy that your comments caused my experiment to work nicely.🙏🙏🙏

  Thanks again,

  Sami
• Daniel

  April 2020

  Hi @Sami,

  I'm glad I could help

  I faced another problem in the "feedback item" in OSweb. average reaction time (avg_rt) and accuracy percent (acc)% were not seen in the feedback item at the end of practice.

  This is solved now, since you are speaking about this in past tense? :)

  
• Sami

  April 2020

  sorry. It seems that my English isn't very good. 😊

  No, it is not solved until now.
• DavidTU

  May 2021

  Hello,

  I am experiencing a similar problem with my working memory experiment. Participants are required to judge each sentence (auditory presentation) for plausibility and subsequently recall the last word of each sentence.

  The experiment works fine when I run it normally but fails to do so in a browser.

  In Chrome I get:

  Uncaught TypeError: Cannot read property 'data' of undefined

  In Firefox I get:

  TypeError: r is undefined

  
  

  Could someone please have a look at my experiment? Many thanks in advance.

  Total runtime of the experiment as of now is < 1 minute as it only has one trial consisting of three sentences + recall.

  WM task.osexp

  
  
• DavidTU

  May 2021

  Sorry for double-posting. I have fixed the error now (turned out there were files missing from the filepool).