Lazycoder

All XML based messages are just POX over the wire

Let's take the example SOAP message provded by the W3C.

Let's break it down into what's important to us.

Stuff we don't care about

Stuff we do care about

Stuff we don't care about

See all that stuff we don't care about is what I call the message tax. Sometimes, as with TCP/IP messages, it's important to pay the message tax. HTTP headers are another message tax it's pretty important to pay. But consider what we are getting for our dollar when we pay the SOAP, or any other WS* tax. Why do I say that the stuff in the message header is stuff we don't care about? Well, in the context of the user-facing portion of the application, none of that does matter. All that matters is that we can get to the message, the actual payload, parse it out, and do something with it.

I asked Phil a leading question over on his blog. He responded by asking, "...without the end tags, are you sure you got the whole message?". Good point, but we'll find that out when we try to parse the payload anyway.

If you only received this message:

Could you still get to the msg element? Sure, using a SAX-style parser. A DOM parser might choke on it. But you might not really care about the information in the header. Heck, you could just use a text-stream reader. What about instead of the XML fragment above all you got was this.

Heck, you don't even need a fancy parser to handle that. Just take everything right of the "=" and off you go.

Is my point that SOAP/XML-RPC/WS-* suck? No, but you should voluntarily pay the message tax. Don't assume that just because you are using a "web service" that you need to use a known messaging scheme.

Old computer viruses

I was reading a forum thread today about the Vista release slip and Larry Osterman mentioned working on NT 3.1. Someone in the forum said it was the most stable OS they'd ever used. I said DOS 5 was the most stable. Probably the most secure, it didn't ship with a networking stack! You had to download viruses and run them manually. But I remember two of my favorite computer viruses from way, way back.

Cookie Monster: This one was pretty harmless. It would occasionally pop up a message on a users terminal and say "I want a cookie!". If the user typed in "cookie", it went away for a while. If they typed in "Oreo", it went away for good. The link is to the source code for the original

Ambulance: Randomly, a graphical ambulance would scroll across the bottom of the users screen and a siren would play over the speaker.