Simple UrlRewriter for EpiServer

On an EpiServer project that I just finished there was a requirement that all URLs generated by the CMS should be lowercase. I couldn't really see the issue. I know that web servers are allowed to be case sensitive with URLs, but didn't really see the big deal.

However, looking at EpiServer, I thught that I might re-write a PageData extension method which I wrote previously which generates the external URL of a page:

public static string GetExternalUrl(this PageData page)
{
string result = String.Empty;

if (page != null)
{
UrlBuilder builder = new UrlBuilder(page.LinkURL);
EPiServer.Global.UrlRewriteProvider.ConvertToExternal
(builder, page, Encoding.UTF8);

result = builder.ToString();
}

return result;
}

This might have worked, but was still a bit of a kludge, so I turned to the undocumented waters of the EPiServer.Web.FriendlyUrlRewriteProvider

The FriendlyUrlRewriteProvider has a virtual method called:

ConvertToExternalInternal(EPiServer.UrlBuilder url, object internalObject, Encoding toEncoding)

Which is called by the EPiServer.Global.UrlRewriteProvider.ConvertToExternal(...) method I use in the Extension method above. Overriding that mehtod and converting the UrlBuilder's path property to lowercase seemed to do the trick.

Here's the final class:

public class LowerCaseUrlRewriteProvider : EPiServer.Web.FriendlyUrlRewriteProvider
{
public LowerCaseUrlRewriteProvider()
: base()
{

}

protected override bool ConvertToExternalInternal
(EPiServer.UrlBuilder url, object internalObject, Encoding toEncoding)
{
base.ConvertToExternalInternal(url, internalObject, toEncoding);

url.Path = url.Path.ToLower();

return true;
}
}

Update: Setting it up in the Web.Config

You now need to add this to the urlRewrite EpiServer config element in the Web.Config:

      <urlRewrite defaultProvider="LowerCaseUrlRewriteProvider">
          <providers>
              <add name="LowerCaseUrlRewriteProvider" type="Shared.EpiServer.Web.LowerCaseUrlRewriteProvider,Shared.EpiServer" />
              <add name="EPiServerFriendlyUrlRewriteProvider" type="EPiServer.Web.FriendlyUrlRewriteProvider,EPiServer" />
              <add description="EPiServer identity URL rewriter" name="EPiServerIdentityUrlRewriteProvider"
                  type="EPiServer.Web.IdentityUrlRewriteProvider,EPiServer" />
              <add description="EPiServer bypass URL rewriter" name="EPiServerNullUrlRewriteProvider"
                  type="EPiServer.Web.NullUrlRewriteProvider,EPiServer" />
          </providers>
      </urlRewrite>