... personal wiki, blog and notes
Bryan's Blog 2005/02/28
What is a Web Service
Last week I gave a kick off talk at the National Institute for Environmental e-Science (niees) on "What is a Web Service". This was in a meeting on "Developing applications for real-time environmental data" (DARTED).
In that (short) talk, I spent a few minutes on the SOAP v REST wars, because I think the environmental community could be sold a dummy if they put too much work into mis-applying technologies. In particular, I do believe that while there is a place for SOAP-ful web services in some applications (we are using them in NDG), in many cases it's simply not worth the effort. The trick is going to be deciding at project conception whether one needs the full WS machinery or not.
If everything is sent over the wire as a XML document that is described by an XSD then it all boils down to how easy you can work with these documents. That is working with XML api's like DOM and XPath. The enclosing envelope should be irrelevant to the concerns of the average developer; it should be treated like just any other transport protocol.
The same article goes on to say:
All that extra machinery provided to support the SOAP envelope is precisely that, extra machinery and has never been shown to improve interoperability. Therefore, in terms of effort, interoperability via SOAP is not any easier than doing it in REST. In fact, its actually more insidious because a developer is all too easily lulled in the fallacy that an object is the same as the XML document.
Which goes to show that this battle at least is about interoperability. I don't know where the truth is here yet, so I'm happy to keep on reading about it. But it's not all about interoperability, we need to add security to the mix, and if I have the same code base at each end of the wire (or not), using WS-whatever and/or SOAP may be easier than doing it all (over again) RESTfully. As I say, I really don't know how this war will pan out, but I do know that NDG needs X509 (proxy) certificates, and XML-signature, and probably a fair hunk of WSRF (or something like it) ... so if we can have it in a SOAP toolkit, we'll use it!
Internet Explorer REALLY Sucks
I've been aware that my blog didn't render properly on internet explorer. I thought it was probably because my CSS and/or my XHTML weren't standards compliant. So, I've done some testing. My new wikiBNL code and my style sheed have been tested with
It passes both. Now, all newer pages should render correctly, but perhaps I can understand it if the older (non standards compliant) ones don't. And what was the problem? IE didn't like comments in the CSS file (which stopped it being valid CSS, but didn't stop other browsers from getting it right).
I'm obviously not the only person with major problems with Internet Explorer. I think this open letter to Bill Gates says it all.