Answering comments is turning out to be more interesting than trying to explain my ideas which is, I suppose, part of the idea behind Blogs. In any case, I’ve had a slew of comments about REST. I admit to not being a REST expert and the people commenting, Mike Dierkin and Mark Baker in particular, certainly are. They tell me I’m all wet about the REST issues. I’ll dig into it. But I admit, I don’t get it. I need to be educated. I’m talking to our guy, Mark Nottingham, about this who does understand it all, but I also will be at XML 2003 in Philadelphia on Wednesday if people want to explain to me the error of my ways.
Let me explain why I’m confused. I don’t want to depend upon HTTP because I want to be able to use things like IM as a transport, particularly Jabber. So I want some protocol neutral way to move information back and forth. Maybe I’m wrong here, but I’m particularly wary of HTTP because in many cases I want the “sender” of the message to know reliably that the receiver has it. How does REST handle this? I’m going to try and find out. Secondly, whenever I send a set of messages to a set of services and responses start coming back, I want a standard protocol level way to correlate the responses with the sent messages. How do I do this without depending on the HTTP cookie and without the poor programmer having to worry about the specific headers and protocols? Again, I need to learn. Third, I DO believe in being able to describe a site so that programming tools can make it easy/transparent to read/write the requests and responses without the programmer thinking about the plumbing and formats. How is this done in the REST world? What’s the equivalent of WSDL. Sure WSDL is horribly complex and ugly. But what is the alternative here? I don’t mind, to tell the truth, if the description is URL centric rather than operation-centric, but I do want to know that the tooling “knows” how to build the appropriate Request. I care about programming models. Fourth, as I’ve said before, I think that the model for the moblized browser communicating with the internet is frequently going to be a fairly subtle query/context based synchronization model. For example, given the context of a specific trip and some cached details, update me with the latest details. Given the context of a specific project and some cached tasks and team members, update me with the latest tasks, team members, etc for that project. How do I do this in the REST model given that this isn’t trying to change the data on the server and that I need to pass in both the context, the implicit query, and the data I already know? Fifth, how do I “subscribe” to “Events” and then get “unsolicited messages” when someone publishes something I want to know about? KnowNow has been doing this for years, (Hi Rohit), but how do I do this in REST. So, REST folks, feel free to send me mail explaining all this to me. I’m trying to learn.
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