private static IHtmlContent BooleanTemplateCheckbox(IHtmlHelper htmlHelper, bool value)
 {
     return htmlHelper.CheckBox(
         expression: null,
         isChecked: value,
         htmlAttributes: CreateHtmlAttributes(htmlHelper, "check-box"));
 }

        private static string buildActionLink(IHtmlHelper helper,
                                      string linkText,
                                      int pageParam)
        {
            if (helper.ViewContext.HttpContext.Request.QueryString.HasValue)
            {
                var queryString = QueryHelpers.ParseQuery(helper.ViewContext.HttpContext.Request.QueryString.Value);
                string[] sort, categoryId;
                queryString.TryGetValue("SortExpression", out sort);
                queryString.TryGetValue("CategoryId", out categoryId);

                return helper.ActionLink(linkText,
                               helper.ViewContext.RouteData.Values["action"].ToString(),
                               new
                               {
                                   SortExpression = sort,
                                   CategoryId = categoryId,
                                   Page = pageParam
                               }).ToString();
            }
            else
            {
                return helper.ActionLink(linkText,
                               helper.ViewContext.RouteData.Values["action"].ToString(),
                               new
                               {
                                   Page = pageParam
                               }).ToString();
            }
        }

 public ComponentTagHelper(IHttpContextAccessor contextAccessor, IBricsContextAccessor bricsContext)
 {
     _contextAccessor = contextAccessor;
     _bricsContext = bricsContext;
     _urlHelper = contextAccessor.HttpContext.RequestServices.GetService<IUrlHelper>();
     _htmlHelper = contextAccessor.HttpContext.RequestServices.GetService<IHtmlHelper>();
 }

 private static string BooleanTemplateDropDownList(IHtmlHelper html, bool? value)
 {
     return html.DropDownList(
         string.Empty,
         DefaultDisplayTemplates.TriStateValues(value),
         CreateHtmlAttributes(html, "list-box tri-state"))
             .ToString();
 }

        public void AddBackofficeBottom(string urlstring, IUrlHelper url, IHtmlHelper html)
        {
            const string prefix = @"~/Areas/Backoffice/Scripts/framework/";
            urlstring = urlstring.TrimStart('/');

            var path = string.Format("{0}{1}", url.Content(prefix), (urlstring.EndsWith(".js") ? urlstring : urlstring + ".js"));
            html.Statics().FooterScripts.Add(path);
        }

 private static IHtmlContent BooleanTemplateDropDownList(IHtmlHelper htmlHelper, bool? value)
 {
     return htmlHelper.DropDownList(
         expression: null,
         selectList: DefaultDisplayTemplates.TriStateValues(value),
         optionLabel: null,
         htmlAttributes: CreateHtmlAttributes(htmlHelper, "list-box tri-state"));
 }

        public HtmlGridTests()
        {
            html = Substitute.For<IHtmlHelper>();
            html.ViewContext.Returns(new ViewContext());
            html.ViewContext.HttpContext = new DefaultHttpContext();
            grid = new Grid<GridModel>(new GridModel[8]);

            htmlGrid = new HtmlGrid<GridModel>(html, grid);
            grid.Columns.Add(model => model.Name);
            grid.Columns.Add(model => model.Sum);
        }

 private static string SectionContent(IHtmlHelper html, ISitePage sitepage, IPageSection model)
 {
     using (StringWriter result = new StringWriter())
     {
         foreach (var item in model.Items)
         {
             item.Page = sitepage;
             html.Partial(item.Template, item).WriteTo(result, HtmlEncoder.Default);
         }
         return result.ToString();
     }
 }

        public static IHtmlContent BooleanTemplate(IHtmlHelper htmlHelper)
        {
            bool? value = null;
            if (htmlHelper.ViewData.Model != null)
            {
                value = Convert.ToBoolean(htmlHelper.ViewData.Model, CultureInfo.InvariantCulture);
            }

            return htmlHelper.ViewData.ModelMetadata.IsNullableValueType ?
                BooleanTemplateDropDownList(htmlHelper, value) :
                BooleanTemplateCheckbox(htmlHelper, value ?? false);
        }

 public GridTagHelper(IOptions<MvcViewOptions> optionsAccessor,
     IHtmlHelper html, 
     IHttpContextAccessor httpAccessor, IViewComponentHelper component, 
     IUrlHelperFactory urlHelperFactory,
     IStringLocalizerFactory factory)
 {
     IdAttributeDotReplacement = optionsAccessor.Value.HtmlHelperOptions.IdAttributeDotReplacement;
     this.html = html;
     this.httpAccessor = httpAccessor;
     this.component = component;
     this.urlHelperFactory = urlHelperFactory;
     this.factory = factory;
 }

 //workaround forr issue https://github.com/aspnet/Mvc/issues/2430
 private static string getEnumDisplayName(Type type, string o, IHtmlHelper h)
 {
     string displayName = null;
     
     foreach (SelectListItem item in h.GetEnumSelectList(type))
     {
         if (o == item.Value)
         {
             displayName = item.Text ?? item.Value;
         }
     }
     return displayName;
 }

        private static string BooleanTemplateCheckbox(bool value, IHtmlHelper htmlHelper)
        {
            var inputTag = new TagBuilder("input", htmlHelper.HtmlEncoder);
            inputTag.AddCssClass("check-box");
            inputTag.Attributes["disabled"] = "disabled";
            inputTag.Attributes["type"] = "checkbox";
            if (value)
            {
                inputTag.Attributes["checked"] = "checked";
            }

            return inputTag.ToString(TagRenderMode.SelfClosing);
        }

        public static StaticsHelper GetInstance(IHtmlHelper htmlHelper)
        {
            const string instanceKey = "8F3AC534-E5B1-4C51-B5A9-ED0EAC731633";

            var context = htmlHelper.ViewContext.HttpContext;
            if (context == null) return null;

            var assetsHelper = (StaticsHelper)context.Items[instanceKey];

            if (assetsHelper == null)
                context.Items.Add(instanceKey, assetsHelper = new StaticsHelper());

            return assetsHelper;
        }

        private static IHtmlContent BooleanTemplateCheckbox(bool value, IHtmlHelper htmlHelper)
        {
            var inputTag = new TagBuilder("input");
            inputTag.AddCssClass("check-box");
            inputTag.Attributes["disabled"] = "disabled";
            inputTag.Attributes["type"] = "checkbox";
            if (value)
            {
                inputTag.Attributes["checked"] = "checked";
            }

            inputTag.TagRenderMode = TagRenderMode.SelfClosing;
            return inputTag;
        }

        private static IHtmlContent BooleanTemplateDropDownList(IHtmlHelper htmlHelper, bool? value)
        {
            var selectTag = new TagBuilder("select");
            selectTag.AddCssClass("list-box");
            selectTag.AddCssClass("tri-state");
            selectTag.Attributes["disabled"] = "disabled";

            foreach (var item in TriStateValues(value))
            {
                selectTag.InnerHtml.Append(DefaultHtmlGenerator.GenerateOption(item, item.Text));
            }
            
            return selectTag;
        }

        private static HtmlString createPostBackLink(IHtmlHelper helper,
                                              string text,
                                              string actionName,
                                              string controller)
        {
            var vpc = new VirtualPathContext(
                helper.ViewContext.HttpContext,
                null,
                (new RouteValueDictionary {
                      { "controller", controller },
                      { "action", actionName } })

                      );
            var actionUrl = helper.ViewContext.RouteData.Routers[0].GetVirtualPath(vpc);

            return new HtmlString(String.Format(@"<a href=""#"" class=""btn btn-default"" onclick=""wizard.WizardSubmit('{0}')"">{1}</a>",
                  actionUrl, text));
        }

        private static string BooleanTemplateDropDownList(IHtmlHelper htmlHelper, bool? value)
        {
            var selectTag = new TagBuilder("select", htmlHelper.HtmlEncoder);
            selectTag.AddCssClass("list-box");
            selectTag.AddCssClass("tri-state");
            selectTag.Attributes["disabled"] = "disabled";

            var builder = new StringBuilder();
            builder.Append(selectTag.ToString(TagRenderMode.StartTag));

            foreach (var item in TriStateValues(value))
            {
                var encodedText = htmlHelper.Encode(item.Text);
                var option = DefaultHtmlGenerator.GenerateOption(item, encodedText, htmlHelper.HtmlEncoder);
                builder.Append(option);
            }

            builder.Append(selectTag.ToString(TagRenderMode.EndTag));
            return builder.ToString();
        }

 private static IHtmlContent GenerateTextBox(IHtmlHelper htmlHelper, object value, object htmlAttributes)
 {
     return htmlHelper.TextBox(
         current: null,
         value: value,
         format: null,
         htmlAttributes: htmlAttributes);
 }

        private static void ApplyRfc3339DateFormattingIfNeeded(IHtmlHelper htmlHelper, string format)
        {
            if (htmlHelper.Html5DateRenderingMode != Html5DateRenderingMode.Rfc3339)
            {
                return;
            }

            var metadata = htmlHelper.ViewData.ModelMetadata;
            var value = htmlHelper.ViewData.Model;
            if (htmlHelper.ViewData.TemplateInfo.FormattedModelValue != value && metadata.HasNonDefaultEditFormat)
            {
                return;
            }

            if (value is DateTime || value is DateTimeOffset)
            {
                htmlHelper.ViewData.TemplateInfo.FormattedModelValue =
                    string.Format(CultureInfo.InvariantCulture, format, value);
            }
        }

        public static IHtmlContent FileCollectionInputTemplate(IHtmlHelper htmlHelper)
        {
            if (htmlHelper == null)
            {
                throw new ArgumentNullException(nameof(htmlHelper));
            }

            var htmlAttributes =
                CreateHtmlAttributes(htmlHelper, className: "text-box single-line", inputType: "file");
            htmlAttributes["multiple"] = "multiple";

            return GenerateTextBox(htmlHelper, htmlHelper.ViewData.TemplateInfo.FormattedModelValue, htmlAttributes);
        }