Asp.Net MVC CheckBoxList HtmlHelper Extension
I added some more methods to the code provided by Tyler Garlick’s CheckBoxList for ASP.net MVC to allow a dictionary to be passed in place of a list of SelectListItems and an optional list of selected ids. Anyway, here’s the full class.
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace System.Web.Mvc
{
public static class CheckBoxListHelper
{
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items)
{
return CheckBoxList(helper, name, items, null, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IDictionary<string, object> checkboxHtmlAttributes)
{
return CheckBoxList(helper, name, items, null, checkboxHtmlAttributes);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IEnumerable<string> selectedValues)
{
return CheckBoxList(helper, name, items, selectedValues, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IDictionary<string, string> items, IEnumerable<string> selectedValues, IDictionary<string, object> checkboxHtmlAttributes)
{
var selectListItems = from i in items
select new SelectListItem
{
Text = i.Key,
Value = i.Value,
Selected = (selectedValues != null && selectedValues.Contains(i.Value))
};
return CheckBoxList(helper, name, selectListItems, checkboxHtmlAttributes);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> items)
{
return CheckBoxList(helper, name, items, null);
}
public static string CheckBoxList(this HtmlHelper helper, string name, IEnumerable<SelectListItem> items, IDictionary<string, object> checkboxHtmlAttributes)
{
var output = new StringBuilder();
foreach (var item in items)
{
output.Append(“<div class=\"fields\”><label>“);
var checkboxList = new TagBuilder("input”);
checkboxList.MergeAttribute(“type”, “checkbox”);
checkboxList.MergeAttribute(“name”, name);
checkboxList.MergeAttribute(“value”, item.Value);
// Check to see if it’s checked
if (item.Selected)
checkboxList.MergeAttribute(“checked”, “checked”);
// Add any attributes
if (checkboxHtmlAttributes != null)
checkboxList.MergeAttributes(checkboxHtmlAttributes);
checkboxList.SetInnerText(item.Text);
output.Append(checkboxList.ToString(TagRenderMode.SelfClosing));
output.Append(“ ” + item.Text + “</label></div>”);
}
return output.ToString();
}
}
}
On the view you can pass a dictionary made from items in your view model and selected values form your view model.
<div>
${Html.CheckBoxList(“Product.Categories”,
ViewData.Model.Categories.ToDictionary(c => c.Name, c => c.Id.ToString()),
ViewData.Model.Product.Categories.Select(c => c.Id.ToString()))}
</div>
In the controller you can access the form values in the request as a comma list of values by the name of the form field.
Request.Form[“Product.Categories”]
Hope this helps and thanks to Tyler Garlick for meat of the code.
[UPDATE] Tyler has updated is code for MVC 2.0, here.
