StringBuilder Extensions

I recently had a requirement to modify some Html-based reports.  These reports were built up in code using a StringBuilder, along with report content data.  The plus-point is that it worked and delivered the desired reports.  On the downside, the code was tedious and verbose.  For example:

StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append("<TABLE id=\"Table2\" width=\"100%\">");
stringBuilder.Append("<TR style=\"page-break-inside : avoid\"><TD class=\"reportHeaderTitle\" >" + ResourceManager.GetString("ReportTitle", culture) + "</TD></TR>");
stringBuilder.Append("<TR><TD style=\"PADDING-LEFT: 5px; PADDING-BOTTOM:10px\" width=\"100%\">");
stringBuilder.Append("<TABLE id=\"Table2\" width=\"100%\">");
stringBuilder.Append("<TR style=\"page-break-inside : avoid\"><TD class='reportHeader' align=\"center\" width=\"50%\">" + ResourceManager.GetString("ReportSubTitle", culture) + "</TD>");
stringBuilder.Append("<TD class='reportHeader' align=\"center\" width=\"50%\">" + ResourceManager.GetString("ReportResults", culture) + "</TD></TR>");
...

I was staring at 1000s of lines of code like this.  After a while it was all a blur.

My first impulse was to subclass the StringBuilder and build up some Html-specific methods.  Unfortunately, the StringBuilder class is sealed.   I also looked at the HtmlTextWriter class, a class primarily used when working with custom server controls.  But, this seemed overkill for the purpose.  I just needed a clean way to build-up an Html string in code.

I then turned to writing a set of Extensions Methods to provide this functionality.

#region Using Directives

using System.Text;

#endregion

namespace Common.Extensions
{
    public static class StringBuilderExtensions
    {
        public static void BeginTable(this StringBuilder stringBuilder)
        {
            stringBuilder.Append("<table>");
        }

        public static void EndTable(this StringBuilder stringBuilder)
        {
            stringBuilder.Append("</table>");
        }

        public static void BeginRow(this StringBuilder stringBuilder)
        {
            stringBuilder.Append("<tr>");
        }
        ...
    }
}

In refactoring the code I first pulled all of the inline styles out and into style classes.  Then I began migrating the existing code over to use the new extension methods.  The refactored code looks something like this:

var stringBuilder = new StringBuilder();
stringBuilder.HorizontalRule();
stringBuilder.BeginH2();
stringBuilder.Append(ResourceManager.GetString("ReportTitle", _Culture));
stringBuilder.EndH2();

stringBuilder.BeginTable();
stringBuilder.BeginTHead();
stringBuilder.BeginRow();
stringBuilder.BeginCell("reportHeader");
stringBuilder.Append(ResourceManager.GetString("ReportSubTitle", _Culture));
stringBuilder.EndCell();
stringBuilder.BeginCell();
stringBuilder.Append(ResourceManager.GetString("ReportResults", _Culture));
stringBuilder.EndCell();
stringBuilder.EndRow();
stringBuilder.EndTHead();
...

In it's current state, the extensions only supply the Html tags that were required, but could easily be expanded to support all of the commonly used tags.  I personally find this refactored code much easier to read and maintain.

You can download the StringBuilderExtensions.zip here.
I hope this may be of some use.