_radiobuttonlist.spark

# // Renders a radio button list within the standard GoFetch form field markup including error messages and field hints
# // Parameters
# // name - the name of the form field (required)
# // label - the content of the label associated with the form field (required)
# // options - the options to display (required)
# // hint - the content of the field hint displayed under the form field (optional)
# // defaultoption - the default option that is selected if no other value is specified as selected
# // Remarks
# // options can be supplied as either an IDictionary<string,object> or as an object ( e.g. new { option=value, option2=anothervalue } ).
# // If options is a dictionary the key is the option text and the value is the option value.  If options is an object, the
# // property name will be the option text and the property value the option value.
<default hint="null" type="string" />
<default defaultoption="null" type="object" />

<var radioButtons='Html.CreateRadioButtonList(name, options, defaultoption)' />
<var hasError="Html.Errors(name).HasErrors"/>

<p class="field-message?{hasError} error?{hasError}">
	<span class="label">!{label}</span>
	<for each="var option in radioButtons">
		!{option.RadioButton( new { @class = "radio" } )}
		!{option.Label( new { @class="radio" })}
	</for>
	<span if="hasError" class="validation-message">!{Html.Errors(name).ErrorMessage}</span>
	<span if="!hint.IsNullOrEmpty()" class="field-hint">!{hint}</span>
</p>

RadioButtonList.cs

using System.Collections.Generic;

namespace GoFetchV2.Web.ViewHelpers
{
    public class RadioButtonList : List<RadioButtonListItem>
    {
        public RadioButtonListItem this[ string value ]
        {
            get
            {
                return Find( item => item.Value.Equals( value ) );
            }
        }

        public RadioButtonList( IEnumerable<RadioButtonListItem> collection ) : base( collection ) {}
    }
}

RadioButtonListExtensions.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Web.Mvc;
using System.Linq;

namespace GoFetchV2.Web.ViewHelpers
{
    public static class RadioButtonListExtensions
    {
        public static RadioButtonList CreateRadioButtonList( this HtmlHelper htmlHelper, string name, IEnumerable<KeyValuePair<string, object>> options )
        {
            return htmlHelper.CreateRadioButtonList( name, options, null );
        }

        public static RadioButtonList CreateRadioButtonList( this HtmlHelper htmlHelper, string name, IEnumerable<KeyValuePair<string, object>> options, object defaultOption )
        {
            var selectedValue = htmlHelper.GetFieldValue( name, defaultOption );
            var listItems = options
                .Select(
                option => new {Text = option.Key, Value = Convert.ToString( option.Value, CultureInfo.CurrentCulture )} )
                .Select(( option, index ) => new RadioButtonListItem
                {
                   Id =  name + "_" + index,
                   Name = name,
                   Text = option.Text,
                   Value = option.Value,
                   Selected = String.Equals( selectedValue, option.Value, StringComparison.Ordinal )
                });
            return new RadioButtonList(listItems);
        }
    }
}

RadioButtonListItem.cs

using System.Web.Mvc;
using System.Web.Routing;

namespace GoFetchV2.Web.ViewHelpers
{
    public class RadioButtonListItem : SelectListItem
    {
        public string Id { get; set; }
        public string Name { get; set; }

        public string RadioButton()
        {
            return RadioButton( null );
        }

        public string RadioButton( object htmlAttributes )
        {
            var tagbuilder = new TagBuilder( "input" );
            tagbuilder.MergeAttributes( new RouteValueDictionary( htmlAttributes ) );
            tagbuilder.MergeAttribute( "type", "radio", true );
            tagbuilder.MergeAttribute( "name", Name, true );
            tagbuilder.MergeAttribute( "value", Value );
            tagbuilder.GenerateId( Id );
            if(Selected)
            {
                tagbuilder.MergeAttribute( "checked", "checked" );
            }
            return tagbuilder.ToString( TagRenderMode.SelfClosing );
        }

        public string Label( object htmlAttributes )
        {
            var tagBuilder = new TagBuilder( "label" );
            tagBuilder.MergeAttributes( new RouteValueDictionary( htmlAttributes ) );
            tagBuilder.MergeAttribute( "for", Id, true );
            tagBuilder.InnerHtml = Text;
            return tagBuilder.ToString( TagRenderMode.Normal );
        }
    }
}