custom Dropdownlist does not keep attributes / properties

[mbarmettler]

Hi,

i try to create a new widget for showing up countries in a dropdownlist on a form.
sofar the control is initializing and showing up some data.
but - if i try to change the properties on it - for example "required" or "label/question" - it does not keep the values and does not give it back to the designer either.

here is my controller:

``
private ValidatorDefinition validatorDefinition;
private string serializedChoices;

    /// <inheritDocs />
    public string SerializedChoices
    {
        get
        {
            if (string.IsNullOrEmpty(this.serializedChoices))
            {
                this.serializedChoices = this.BuildInitialChoicesString();
                
            }

            return this.serializedChoices;
        }

        set
        {
            this.serializedChoices = value;
        }
    }

    /// <inheritDocs />
    [TypeConverter(typeof(ExpandableObjectConverter))]
    public override ValidatorDefinition ValidatorDefinition
    {
        get
        {
            if (this.validatorDefinition == null)
            {
                this.validatorDefinition = base.ValidatorDefinition;

                this.validatorDefinition.RequiredViolationMessage = Res.Get<FormResources>().RequiredInputErrorMessage;
            }

            return this.validatorDefinition;
        }

        set
        {
            this.validatorDefinition = value;
        }
    }

    /// <inheritDocs />
    public override IMetaField GetMetaField(IFormFieldControl formFieldControl)
    {
        var metaField = base.GetMetaField(formFieldControl);

        if (string.IsNullOrEmpty(metaField.Title))
        {
            metaField.Title = Res.Get<FieldResources>().SelectChoice;
        }

        if (string.IsNullOrEmpty(metaField.DefaultValue))
        {
            var choices = this.DeserializeChoices();
            if (choices.Any())
            {
                metaField.DefaultValue = choices.FirstOrDefault();
            }
        }

        return metaField;
    }
    
    /// <summary>
    /// Prepopulates the initial choices.
    /// </summary>
    /// <returns></returns>
    public virtual string BuildInitialChoicesString()
    {
        var initialChoices = new string[]
        {
            Res.Get<FieldResources>().OptionSelect,
            Res.Get<FieldResources>().OptionFirstChoice,
            Res.Get<FieldResources>().OptionSecondChoice
        };
        return JsonConvert.SerializeObject(initialChoices);
        //var cultureList = LocationContext.Instance.Cultures("en");
        //var orderedcultureList = cultureList.OrderBy(x => x.CountryName).ToList();
        //return JsonConvert.SerializeObject(orderedcultureList.Select(x => x.CountryName).ToArray());
    }

    /// <inheritDocs />
    public override bool IsValid(object value)
    {
        if (this.ValidatorDefinition.Required.HasValue && this.ValidatorDefinition.Required.Value)
        {
            var strValue = value as string;
            if (!string.IsNullOrEmpty(strValue))
            {
                var choices = this.DeserializeChoices();
                if (choices.Contains(strValue))
                {
                    return base.IsValid(value);
                }
            }

            return false;
        }
        else
        {
            return base.IsValid(value);
        }
    }

    public IEnumerable<string> DeserializeChoices()
    {
        if (string.IsNullOrEmpty(this.SerializedChoices))
        {
            return Enumerable.Empty<string>();
        }

        return JsonConvert.DeserializeObject<IEnumerable<string>>(this.SerializedChoices);
    }

    /// <inheritDocs />
    private string BuildValidationAttributesString()
    {
        if (this.ValidatorDefinition.Required.HasValue && this.ValidatorDefinition.Required.Value)
        {
            return "required='required'";
        }

        return string.Empty;
    }

    public override object GetViewModel(object value, IMetaField metaField)
    {
        //workaround
        var cultureList = LocationContext.Instance.Cultures("en");
        var orderedcultureList = cultureList.OrderBy(x => x.CountryName).ToList();

        var countrySelectList = DataObjectConverter<List<SelectListItem>>.ConvertToViewModel(cultureList);

        List<string> countrStrings = new List<string>();
        foreach (var item in orderedcultureList)
        {
            countrStrings.Add(item.CountryName);
        }

        this.Value = value;

        return new CountryViewModel()
        {
            Value = value,
            CssClass = this.CssClass,
            MetaField = metaField,
            IsRequired = this.ValidatorDefinition.Required.HasValue ? this.ValidatorDefinition.Required.Value : false,
            ValidationAttributes = this.BuildValidationAttributesString(),
            RequiredViolationMessage = this.ValidatorDefinition.RequiredViolationMessage,
            Countries = countrySelectList,
            Choices = countrStrings
        };
    }