Blog Post

• Posted by:
• Richard Lee
• 4 comments
• 

Building a website is usually an iterative process. Not many individuals or teams have build a website without having requirements change along the way (If you have then I would like to know the secret). When requirements change sometimes this will require refactoring of the application to elegantly satisfy the business needs.

Some of the refactoring will include url/routes changes leaving many of your previous url/routes returning 404 errors. This is of course a definite no no! If you asked the question why, then here is the answer. After a search engine has indexed your website it remembers those urls/routes and serves them up in the search results. Whenever a user clicks through they either get a 404 error or redirected to another friendly not found page. Now ask yourself this, how often have you clicked through from a search engine and offered a page other than the one you requested and you remained on the website (if you remained longer than 5 seconds then this article is not for you)? The problem doesn't just end there. Imagine you have written a wonderful article and posted it on your wesbite/blog. Your readers have found this article very useful and decided to share it with their friends, then you go and change the url/route (possibly by altering the title); now this article cannot be found from wherever around the internet this url has been shared.

Just a few of the negatives:

1. Reduced traffic
2. Broken Links
3. Unhappy search engines possibly resulting in lower ranking
4. Diminished reputation.

An elegant and simple solution:

	/// 
	/// Base http response result
	/// 
	public class HttpResponseResult : ActionResult
	{
		#region Overrides of ActionResult

		public override void ExecuteResult(ControllerContext context)
		{}

		#endregion
	}

	/// 
	/// 301 redirect
	/// 
	public class PermanentRedirectResult : HttpResponseResult
	{
		private string _url { get; set; }

		public PermanentRedirectResult(string url)
		{
			_url = url;
		}

		#region Overrides of ActionResult

		public override void ExecuteResult(ControllerContext context)
		{
			context.HttpContext.Response.Status = "301 Moved Permanently";
			context.HttpContext.Response.StatusCode = 301;
			context.HttpContext.Response.AddHeader("Location", _url);
			context.HttpContext.Response.Flush();
			context.HttpContext.Response.End();
		}

		#endregion
	}

Now the last and critical part of the entire solution. How do you use the PermanentRedirectResult class. Very simple.

	public class RedirectsController : Controller
	{
		// Map the old path to this action
		public ActionResult DefaultPage()
		{ 
			// Take action
			return new PermanentRedirectResult(Url.Action("Index", "Home"));
		}
		
		// You can even redirect Html pages
		// Simple map the route including the name of the page (somepage.htm)
		private ActionResult HtmlPage()
		{
			return new PermanentRedirectResult(Url.Action("SomePage", "Products"));
		}
	}

Please feel free to post your comments.