Hidden form fields with values

[XanderVertegaal]

Questions that are hidden because of a condition 'remember' the values the user entered previously. This is a problem if a user first enters an invalid value into field A and then changes field B in such a way that field A is hidden. The form as a whole will be invalid, but the user can't see the offending form field.

Can we simply remove QuestionResponses for questions that are not visible after passing through the FormResolver?

[EdoStorm96]

Can we simply remove QuestionResponses for questions that are not visible after passing through the FormResolver?

Yes, I think that is fine!

[EdoStorm96]

This is a bit of a more complicated issue. Firstly you have to understand the structure of our MRForm and how this ties in with a UserFormSubmission.

So we have our MRForm, which is like the blueprint of what a specific form can be. It contains all the info of questions about a form, what conditions apply to them and how they are organized into steps and substeps.

When a user fills in a form, they are filling in a UserFormSubmission. This is a model, that connects to a MRForm, a User and a Study. This is also where all the responses are collected that have been filled in in a form. A response is a QuestionResponse model. This ties to a question and has an answer.

For this issue you'll need to understand the query that gets a form and organizes it. This happens in form.queries.FormQueries.resolve_form(). For getting the Form into the correct shape we use the FormEvaluator and the UserFormResolver. Have a look at these.

The best point to delete a response to a question that is no longer visible would be in UserFormResolver._resolve_question_instances(). There we check if a questions is visible. If it is not we will want to check if the question has a response and, if so, delete it. You can do something like:

question_responses = self.evaluator.responses[question.pk]
if not self.evaluator.is_question_visible(question):
    # Check if there are still responses for this question
    if question_responses:
        for response in question_responses:
            response.delete()
    return []

Then for the repeated questions it is a bit trickier. I would do something like this:

repeat_count = self.evaluator.get_repeat_count_for_question(question)
if len(question_responses) > repeat_count:
    for response in questions_responses:
        if (response.repeat_index+1) > repeat_count:
            response.delete()

I think this should work. Good luck and let me know if you have any other questions!

[RoordinkFrank]

As far as I can see a form saves the hidden field values in the backend. The issue is to remove those. This sounds logical. This should not be saved in the backend at that point.