Question

Lets say I render a Checkbox:

@Html.CheckboxFor(x => x.Checked) // Checked is true by default

ASP will turn that as:

<input checked="checked" data-val="true" data-val-required="The field is required." id="Checked" name="Checked" type="checkbox" value="true" />
<input name="Checked" type="hidden" value="false" />

Since ASP outputs two inputs with the same name for a Checkbox, we also get two GET parameters in the URL when submitting the form with the checkbox:

http://...?Checked=true&Checked=false

Lets say I’m also using MvcContrib for displaying a table with sorting.

When I sort a column, MvcContrib is unable to understand the duplicate GET parameters, and instead of writing ?Checked=true&Checked=false, it writes ?Checked=true%2Cfalse, which can’t be parsed to a bool by MVC3. The error message after sorting is:

String was not recognized as a valid Boolean.

Has anyone else experienced this problem with the MvcContrib grid?

Answer 1

Okay, think I have come up with the solution:

Create your own HtmlTableGridRenderer:

public class CustomTableGridRenderer<TViewModel> : HtmlTableGridRenderer<TViewModel> where TViewModel : class
{
    protected override void RenderHeaderText(GridColumn<TViewModel> column)
    {
        if (IsSortingEnabled && column.Sortable)
        {
            string sortColumnName = GenerateSortColumnName(column);

            bool isSortedByThisColumn = GridModel.SortOptions.Column == sortColumnName;

            var sortOptions = new GridSortOptions
            {
                Column = sortColumnName
            };

            if (isSortedByThisColumn)
            {
                sortOptions.Direction = (GridModel.SortOptions.Direction == SortDirection.Ascending)
                    ? SortDirection.Descending
                    : SortDirection.Ascending;
            }
            else //default sort order
            {
                sortOptions.Direction = column.InitialDirection ?? GridModel.SortOptions.Direction;
            }

            var routeValues = CreateRouteValuesForSortOptions(sortOptions, GridModel.SortPrefix);

            //Re-add existing querystring
            foreach (var key in Context.RequestContext.HttpContext.Request.QueryString.AllKeys.Where(key => key != null))
            {
                if (!routeValues.ContainsKey(key))
                {
                    routeValues[key] = Context.RequestContext.HttpContext.Request.QueryString[key];
                }
            }

            var link = HtmlHelper.GenerateLink(Context.RequestContext, RouteTable.Routes, column.DisplayName, null, null, null, routeValues, null);
            RenderText(link);
        }
        else
        {
            base.RenderHeaderText(column);
        }
    }
}

… and just replace

                if(! routeValues.ContainsKey(key))
                {
                    routeValues[key] = Context.RequestContext.HttpContext.Request.QueryString[key];
                }

… with routeValues[key] = Context.RequestContext.HttpContext.Request.QueryString[key];

And use your new rendering like so:

@Html.Grid()…RenderUsing(new CustomTableGridRenderer())