We're still having this problem even though we corrected what is described in previous post. We can't figure out the pattern for when it happens. Our client is getting alot of complains regarding this from their customers but we haven't been able to find a pattern to when it happens. Sometimes we've been able to see the the incorrect validation but then we try to post again and the problem is gone. 

This is still occurring with no real pattern to when it happens. I've made breakpoints in DataSubmitController->Submit where i can see that a field it's trying to validate shouldn't be visible since the visitor group that wraps the element isn't active. So why is it being validated? Am I the only one with this problem? The form in question is really huge with lots of dependencies and visitor group logic

I think I understand why this is happening. Not sure how to fix it though.

When loading a form container in optimizly the FormContainerBlockController will run the following code:

this._formBusinessService.Service.BuildFormModel(currentBlock);

The BuildFormModel take's the optional parameter buildForAllElements. its' default value is false which is what will be used when loading the container.

    public override void BuildFormModel(FormContainerBlock formContainerBlock, bool buildForAllElements = false)
    {
        if (!(formContainerBlock is IContent formContent))
            return;
        Form currentFormModel = new Form(GetFormGuid(formContent))
        {
            Name = formContent.Name,
            Title = formContainerBlock.Title,
            Description = formContainerBlock.Description,
            RedirectUrl = formContainerBlock.RedirectToPage.GetUrlString(this.GetCurrentFormLanguage(formContainerBlock)),
            AllowAnonymousSubmission = formContainerBlock.AllowAnonymousSubmission,
            AllowMultipleSubmission = formContainerBlock.AllowMultipleSubmission,
            AllowExposingDataFeeds = formContainerBlock.AllowExposingDataFeeds,
            ShowNavigationBar = formContainerBlock.ShowNavigationBar,
            FocusOnForm = formContainerBlock.FocusOnForm,
            ShowSummarizedData = formContainerBlock.ShowSummarizedData,
            ConfirmationMessage = formContainerBlock.ConfirmationMessage,
            ResetConfirmationMessage = formContainerBlock.ResetConfirmationMessage,
            Language = this.GetCurrentFormLanguage(formContainerBlock)
        };
        if (formContent is IChangeTrackable changeTrackable)
        {
            currentFormModel.CreatedDate = changeTrackable.Created;
            currentFormModel.ModifiedDate = changeTrackable.Changed;
        }
        currentFormModel.SourceContent = formContainerBlock.Content;
        this.BuildStepsAndElements(ref currentFormModel, formContainerBlock, buildForAllElements);
        formContainerBlock.Form = (IForm)currentFormModel;
    }
    public virtual void BuildStepsAndElements(
        ref Form currentFormModel,
        FormContainerBlock formContainerBlock,
        bool buildForAllElements = false)
    {
        List<IFormStep> formStepList = new List<IFormStep>();
        List<IFormElement> elements = new List<IFormElement>();
        currentFormModel.Steps = formStepList;
        if (formContainerBlock.ElementsArea == null)
            return;
        foreach (ElementBlockBase elementBlockBase in buildForAllElements ? this.GetAllInnerFormElementBlocks(formContainerBlock) : this.GetDisplayableFormElementBlocks(formContainerBlock))
        {
            IFormElement formElement = elementBlockBase.FormElement;
            if (formElement != null)
            {
                formElement.Form = currentFormModel;
                if (formElement is IFormStep)
                {
                    IFormStep formStep = formElement as IFormStep;
                    formStep.Elements = new List<IFormElement>();
                    formStepList.Add(formStep);
                    if (formStepList.Count >= 2)
                    {
                        this.LinkStepAndItsElements(formStepList[formStepList.Count - 2], elements);
                        elements.Clear();
                    }
                    else if (elements.Count > 0)
                    {
                        formStepList.Insert(0, this.CreateVirtualStep(elements));
                        elements.Clear();
                    }
                }
                else
                    elements.Add(formElement);
                if (elementBlockBase is IElementValidatable)
                    formElement.Validators = this._validationService.Service.GetElementValidators(elementBlockBase as IElementValidatable);
            }
        }
        if (formStepList.Count > 0)
        {
            this.LinkStepAndItsElements(formStepList[formStepList.Count - 1], elements);
            elements.Clear();
        }
        if (formStepList.Count >= 1 || elements.Count <= 0)
            return;
        formStepList.Add(this.CreateVirtualStep(elements));
    }

However, if the site would restart for some reason after loading and before submitting it would mean that the validation logic would need to pull the FormContainerBlock from the database. In that case the following code inside FormContainerBlock.cs would run 

    [Ignore]
    [Newtonsoft.Json.JsonIgnore]
    [System.Text.Json.Serialization.JsonIgnore]
    public IForm Form
    {
      get
      {
        if (this._form == null)
          this._formBusinessService.Service.BuildFormModel(this, true);
        return this._form;
      }
      set => this._form = value;
    }

In this code the buildForAllElements are set to true meaning every form element would be used for validation. This doesn't seem right to me. 

1. Why would you by default want to fetch all elements instead of elements from the context of the user
2. Why does this sporadically happen in production? Why isn't the previously loaded form data from the FormContainerBlockController being used during validation? 

I think this is a bug in optimizely. I've remedied is now by overriding PerformDataSubmitAsync in DataSubmissionService and changed this:

        var formIdentity = new FormIdentity
        {
            Guid = formGuid,
            Language = formLanguage
        };
        var formContainer = formIdentity.GetFormBlock();

to this

        var formIdentity = new FormIdentity
        {
            Guid = formGuid,
            Language = formLanguage
        };
        var formContainer = formIdentity.GetFormBlock();
        
        // CUSTOM CODE START
        _formBusinessService.Service.BuildFormModel(formContainer);
        // CUSTOM CODE END

So since GetFormBlock just does a GetContent from the IContentLoader it will use the Form property of the FormContainerBlock content type and load all elements. My line overrides this behaviour and makes sure only the elements for this users context is loaded and validated.

I would have wanted to to this change in the validation logic only and that might actually be a valid way to go. But I'm worried this bug could affect other things during posting so therefor I wanted to add it when the form container is loaded.

This method im overriding has alot of lines of code which isn't optimal to override since things could change in future versions of EPiServer.Forms. I would love some input from an optimizely employee on this

Hi Andreas Ljungström, since this is a specific case, and not easy to reproduce, I think we better create a Support Case for it, we might need to take a look at your project, log files... before we can decide how to deal with this issue.

Hi Phu Nguyen, did you read the latest things i've written here? I feel like problem is very reproducable now and I think this is a generic bug. Just wanted to know if there is any reason for this behavior or not

To reproduce:

1. Create a form with one element that's hidden for you because of a visitor group.
2. Make the hidden element required
3. Load the form
4. Restart the application
5. Submit the form

This would make sure that the submit doesn't pick up the loaded form from cache and need to reload it and while reloading it, it does so incorrectly. Namely by loading all elements instead of just the user context element which result in an error message that tells you that a form element that isn't even visible for you doesnt validate.

So what i was wondering was if there is anything I'm missing. Why would the submit code want to load all elements instead of just the user context elements?

I've verified this is a problem on an alloy demo site as well

Yes thank you Andreas Ljungström, I can easily reproduce the bug using your steps. I created a bug for this, it will appear in the public bug list soon so you can see the progress at
https://world.optimizely.com/support/Bug-list/bug/AFORM-4374

Hi Phu Nguyen, 

We are still encountering this issue. I successfully replicated it on the Alloy MVC site using the following steps:

1. Install the default Alloy site.
2. Add the latest EPIServer.Forms NuGet package (version 5.10.0 as of 10/18/2024).
3. Create a form with fields for first name, last name, email, and a submit button.
4. Add two additional fields for personalization, ensuring both are marked as required.
5. Create two user accounts.
6. Establish basic audiences with the Criteria Type set to User Profile, using "Username Equals user1" for one and "Username Equals user2" for the other.
7. Apply personalization to the two fields based on the criteria defined in step 6.
8. Create a Standard Page and incorporate the form created earlier.
9. Start the site and load the page in a browser.
10. Log in with user1 to ensure personalized field 1 is displayed.
11. Restart the site.

After filling out the form without reloading the page, the submission failed. Upon checking the network tab, it indicated that personalized field 2 is required.