I have a dropdown datatype which i add to / delete from within the front end on save.

So for example when a company is created on the front end it saves the name and id into a datatype within umbraco, this is then loaded on a create job page so that the user can select the company from a drop down.

I have the code adding it into the prevalues list, however it needs to have the modelbuilder regenerated before it will show the new option in the drop down.

How can i get it to refresh the datatype on save, so that it updates the dropdown instantly rather than requiring a manual modelbuilder regeneration.

Prevalue insert code

            Dictionary<string, PreValue> updatedPreValues = new Dictionary<string, PreValue>();
        var preValues = Services.DataTypeService.GetPreValuesCollectionByDataTypeId(1384).PreValuesAsDictionary;
        if (preValues.Any())
        {
            foreach (var preValue in preValues.Where(pv => !pv.Value.Value.Contains(companyDisplayName)))
            {
                updatedPreValues.Add(preValue.Key, preValue.Value);
            }
        }
        Services.DataTypeService.SavePreValues(1384, updatedPreValues);

Pre Value controller read:

    private SelectList GetSelectListForCompanies()
    {
        var preValueDataType = Umbraco.DataTypeService.GetPreValuesCollectionByDataTypeId(1384);
        var preValues = preValueDataType.PreValuesAsDictionary.Values.Where(pdv => pdv.Value != "0");

        var companiesList = preValues.Select(preValue => new SelectListItem
            {
                Value = preValue.Id.ToString(),
                Text = preValue.Value
            })
            .ToList();

        companiesList.Insert(0, new SelectListItem()
        {
            Text = "Company",
            Value = "0",
            Selected = true,
            Disabled = true
        });

        return new SelectList(companiesList);
    }