Sitecore WFFM Hidden Token Field

HiddenToken.cs

using System.ComponentModel;
using System.Web.UI;
using Sitecore.Form.Core.Attributes;
using Sitecore.Form.Core.Visual;
using Sitecore.Form.Web.UI.Controls;

namespace MyProject.CMS.Custom.WFFM.Fields.HiddenTokenField
{
    public class HiddenToken : InputControl
    {
        protected HiddenToken()
        {
        }

        protected HiddenToken(HtmlTextWriterTag tag)
            : base(tag)
        {
        }

        // Override to hide fields in Form Editor
        public new string CssClass { get; set; }
        public new string Information { get; set; }
        public new string Text { get; set; }


        [VisualFieldType(typeof(ListChoiceField), new object[] { "{7FF10263-1505-48B3-9027-D26FF529D7F1}" })]
        [VisualCategory("Appearance")]
        [VisualProperty("Token Value:", 100)]
        public virtual string TokenValue { get; set; }
        
        [DefaultValue("")]
        [VisualCategory("Appearance")]
        [VisualProperty("Custom Value:", 200)]
        public virtual string CustomTokenValue { get; set; }


        // If we were using ASP.Net WebForms then we'd need to expand this
        private string _value;
        public virtual string Value
        {
            get
            {
                if (TokenValue == "{custom}" || TokenValue == "{fieldname}")
                {
                    return CustomTokenValue;
                }
                return TokenValue;
            }
            set
            {
                this._value = value;
            }
        }

    }
}

HiddenTokenField.cs

using System.ComponentModel;
using Sitecore.Forms.Mvc.ViewModels;
using Sitecore.Forms.Mvc.Interfaces;
using Sitecore.Links;
using Sitecore.WFFM.Abstractions.Actions;

namespace MyProject.CMS.Custom.WFFM.Fields.HiddenTokenField
{
    public class HiddenTokenField : FieldViewModel, IFieldResult, IContainerMetadata
    {
        public virtual string TokenValue { get; set; }
        public virtual string CustomTokenValue { get; set; }
        public string ResultParameters { get; set; }
        
        [DefaultValue("")]
        public virtual string Value { get; set; }

        private string GetTokenValue()
        {
            switch (TokenValue)
            {
                case "{custom}":
                    return CustomTokenValue;
                case "{fieldname}":
                    return Sitecore.Context.Item[CustomTokenValue].Replace("&", "and").Replace('?', '.');
                case "{pageurl}":
                    var options = UrlOptions.DefaultOptions;
                    options.AlwaysIncludeServerUrl = true;
                    return LinkManager.GetItemUrl(Sitecore.Context.Item, options);
                case "{itempath}":
                    return Sitecore.Context.Item.Paths.FullPath;
                case "{itemid}":
                    return Sitecore.Context.Item.ID.ToString();
                case "{shortid}":
                    return Sitecore.Context.Item.ID.ToShortID().ToString();
                default:
                    return TokenValue;
            }
        }

        public virtual ControlResult GetResult()
        {
            return new ControlResult(this.FieldItemId, this.Name, (object)this.Value, this.ResultParameters, false);
        }

        public override void Initialize()
        {
            base.Initialize();
            Value = GetTokenValue();
        }
    }
}

HiddenTokenField.cshtml

@model MyProject.CMS.Custom.WFFM.Fields.HiddenTokenField

@if (!Model.Visible)
{
    return;
}

@Html.HiddenFor(x => Model.FieldItemId)
@Html.HiddenFor(x => Model.Value)