Creating custom Html Helper: MyHelperFor

Question

I would like to create a helper that can be used like

@Html.MyHelperFor(m => m.Name)

this should return for example

Answer 1

Following up on mattytommo's answer, this works great but there is only a small problem when used with complex objects, such as if you are using this code for a property inside an EditorTemplate.

Instead of

var data = ModelMetadata.FromLambdaExpression(expression, helper.ViewData);
string propertyName = data.PropertyName;

If using MVC4, you can change it to

var propertyName = helper.NameFor(expression);

or for MVC3 and below

var propertyName = expression.Body.ToString();
propertyName = propertyName.Substring(propertyName.IndexOf(".") + 1);
if (!string.IsNullOrEmpty(helper.ViewData.TemplateInfo.HtmlFieldPrefix))
    propertyName = string.Format("{0}.{1}", helper.ViewData.TemplateInfo.HtmlFieldPrefix, propertyName);

Full code:

    public static MvcHtmlString MyHelperFor(this HtmlHelper helper, Expression> expression, object htmlAttributes = null)
    {
        var propertyName = expression.Body.ToString();
        propertyName = propertyName.Substring(propertyName.IndexOf(".") + 1);
        if (!string.IsNullOrEmpty(helper.ViewData.TemplateInfo.HtmlFieldPrefix))
            propertyName = string.Format("{0}.{1}", helper.ViewData.TemplateInfo.HtmlFieldPrefix, propertyName);

        TagBuilder span = new TagBuilder("span");
        span.Attributes.Add("name", propertyName);
        span.Attributes.Add("data-something", propertyName);

        if (htmlAttributes != null)
        {
            var attributes = HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
            span.MergeAttributes(attributes);
        }

        return new MvcHtmlString(span.ToString());
    }