interceptionexceptionbehavior.cs

public abstract class InterceptExceptionBehavior<T> : IActionBehavior
		where T : Exception
	{
		public IActionBehavior InsideBehavior { get; set; }

		public void InvokePartial()
		{
			if (InsideBehavior != null)
				InsideBehavior.InvokePartial();
		}

		public void Invoke()
		{
			if (InsideBehavior == null)
				throw new FubuAssertionException("When interception exceptions you must have an inside behavior. Otherwise, there would be nothing to intercept.");

			try
			{
				InsideBehavior.Invoke();
			}
			catch (T exception)
			{
				if (!ShouldHandle(exception))
					throw;

				Handle(exception);
			}
		}

		public virtual bool ShouldHandle(T exception)
		{
			return true;
		}

		public abstract void Handle(T exception);
	}

	public class LuceneStatusExceptionBehavior : InterceptExceptionBehavior<Exception>
	{
		private readonly IOutputWriter _outputWriter;
		private readonly IHttpResponseStatus _httpResponseStatus;

		public LuceneStatusExceptionBehavior(IOutputWriter outputWriter, IHttpResponseStatus httpResponseStatus)
		{
			_outputWriter = outputWriter;
			_httpResponseStatus = httpResponseStatus;
		}

		public override bool ShouldHandle(Exception exception)
		{
			return exception.GetType().FullName.Contains("Lucene");
		}

		public override void Handle(Exception exception)
		{
			_httpResponseStatus.Code = 400;

			var htmlDocument = getHttpStatusErrorDocument(exception, _httpResponseStatus.Code);
			_outputWriter.Write("text/html", htmlDocument.ToString());
		}

		private static HtmlDocument getHttpStatusErrorDocument(Exception exception, int httpStatusCode)
		{
			var title = "Status " + httpStatusCode;

			var doc = new HtmlDocument {Title = title};
			var content = doc.Add("div").AddClass("content");
			content.AddChildren(
				new[]
				{
					new HtmlTag("h1").Text(title),
					new HtmlTag("p").Text("Your Dovetail Seeker search API request failed."),
					new HtmlTag("h2").Text("Reason"),
					new HtmlTag("p").Text(exception.Message)
				});

			return doc;
		}
	}