In my last post, I showed how I used an HtmlHelper to create an enumerable-based dropdown. In this post, I’ll share a few more HtmlHelpers I’ve created to make life easier, or the user experience better.

There are places in DevEvents, like the directory listings where it would not be optimal to display the whole text of a speaker or event description. In such cases, I use an HtmlHelper to truncate the text, and optionally append a ‘more info’ link. To make it even better, you might consider finding the next space (‘ ‘), and truncating there.

public static string TruncateText(this HtmlHelper helper, string text, int maxLength, string postFix)
{
    if (text != null && text.Length > maxLength)
        return text.Substring(0, maxLength) + postFix;

    return text;
}

ResolveUrl is a very handy method, but it isn’t available everywhere I needed it to be, like inside other HtmlHelpers, so I created my own ResolveUrl HtmlHelper.

public static string ResolveUrl(this HtmlHelper helper, string url)
{
    if (url.StartsWith("~/"))
    {
        string siteRoot = helper.ViewContext.HttpContext.Request.ApplicationPath;
        
        if (siteRoot == string.Empty)
            siteRoot = "/";
        
        return url.Replace("~/", siteRoot);
    }
    else
    {
        return url;
    }
}

The HTML construct of ‘<label for’ is very helpful for individuals with accessibility issues and non-standard browsers. Instead of having to write out the whole HTML every time, I created an HtmlHelper:

public static string LabelFor(this HtmlHelper helper, string target, string text)
{
    return String.Format("<label for='{0}'>{1}</label>", target, text); 
}

One common website complaint is that text is not pluralized correctly. I created a very simple HtmlHelper to do just this:

public static string PluralizeText(this HtmlHelper helper, string singularText, string pluralText, int number)
{
    if (number == 1)
        return singularText;
    else
        return pluralText;
}

public static string Image(this HtmlHelper helper, string url, object htmlAttributes)
{
    StringBuilder sb = new StringBuilder();
    sb.Append("<img  src=\"" + helper.ResolveUrl(url) + "\"");

    IDictionary<string, object> attributes = new RouteValueDictionary(htmlAttributes);

    if (attributes != null)
    {
        foreach (var item in attributes)
        {
            sb.Append(" " + item.Key + "=\"" + item.Value.ToString() + "\"");
        }
    }

    sb.Append(" />");

    return sb.ToString();
}

The introduction of anonymous types, generics, and other .NET 3.0 features also introduces some complexity when working with Nullable types. To facilitate these scenarios, I created the following HtmlHelper: (Updated 1/14/2009: Made it a generic method thanks to Liam’s comment below)

public static string FormatNullable<T>(this HtmlHelper helper, Nullable<T> nullable, string format, string emptyText) 
    where T : struct
{
    if (nullable.HasValue)
        return string.Format(format, nullable.Value);
    else
        return emptyText;
}

Hopefully you will find one or more of these HtmlHelpers helpful in your .NET MVC development. What custom HtmlHelpers do you use? Would you do any of these differently?