One year ago it became clear that Infovark had outgrown the Windows Communication Foundation (WCF).
We’d decided to use WCF because we wanted Infovark to provide web services, and we liked the fact that we could deploy WCF to client machines. Since WCF is built directly on top of HttpListener, a core part of the Microsoft .NET Framework, we wouldn’t need to use System.Net or Microsoft IIS.
But we’ve struggled with WCF for a variety of reasons. First, we wanted to use a REST model for our web services, and WCF’s support for REST architectures lags behind its SOAP support.
Second, there’s no easy way to return HTML from WCF. We tried transforming our XML with XSLT and returning the XHTML results as a Stream. This works, but the programming experience is frustrating.
Last, because of the previous two reasons, we were left with a website that was way too rigid and programmer-like. It didn’t feel like an organic website. The tool we’d picked was forcing us to compromise on our website design goals.
Infovark’s primary mission is to help human beings, not other computers. That means that the look and feel of the web interface should be our number one priority. Awesome web services are nice to have, but happy users are more important.
So for the past few months, we’ve been hunting for an alternative web server. We can’t use IIS because its footprint is too heavy. Most IT departments won’t allow us to install IIS on client machines.
We could use Apache. It has a nice embeddable version, but interacting with it via C# is tricky. We’d prefer something a little more Microsoft-native.
That basically leaves us with one commercial option and two open source options.
(If you know of other web servers worth investigating, please let us know in the comments!)
More important than picking an alternative web hosting framework for Infovark is the timing of the switch. We don’t want to impede future development.
As a stopgap, we might try plugging in the Spark View Engine to replace our current XML-XSLT-XHTML rendering path. Who knows? If it improves our web development flow, we might be able to keep our WCF base after all.
I ran into a problem yesterday. I’d sent a HTTP POST request to a collection of resources on our RESTful web service. Our server responded with an HTTP 201: Created status code and the URI of the new resource in the Location header.
And then… nothing happened.
This was not what I was expecting. I expected my web browser to follow up with a GET request to the URI I’d provided. But Firefox 3 wasn’t biting. A problem with Firefox? I checked in IE8 and Google Chrome and got the same behavior.
Had I misread the HTTP spec? Did I misunderstand the REST pattern? I grabbed for my worn copy of RESTful Web Services. Nope. HTTP 201 seemed to be the right status for this situation.
Had I blundered into some common error? I checked Stefan Tilkov’s useful list of REST Antipatterns. But I couldn’t find anything that quite matched my situation.
I started Googling, but couldn’t find much apart from this question about HTTP Post on Stack Overflow. There were some cryptic responses (to which I’ve added my own answer now).
Eventually, I discovered what I needed to know from Ben Ramsey’s article on HTTP redirection. It’s part of his series discussing RFC 2616, which describes the HTTP/1.1 protocol.
The answer is that while web service clients will often “take the hint” provided by a HTTP 201: Created response, web browsers won’t. If you actually want a web browser to go somewhere else, you need to send a status code in the 3xx series. In this situation, the status code you want is HTTP 303: See Other.
Once I changed the status code returned by the server, all the web browsers followed up the response with a GET to the new URI.