On 13 May 2009, at 15:13, Sam Johnston wrote:
On Wed, May 13, 2009 at 3:40 PM, Roger Menday <roger.menday@uk.fujitsu.com
wrote: I am not feeling comfortable with having a state model which will change on the fly, depending what a resource will answer. For one thing, it will make user interfaces and tools really difficult to design:
- should I add a suspend button, even if it works only sometimes? - if it worked once, will it work again? - what can I do if it does not work? I want to suspend, dammit! ;-)
I don't share your pessimism, but then again, I also think we are getting our wires crossed. I think there is a lot of help here from hateoas which does a lot to address your concerns above (??)
That was exactly the point of introducing both together - given that most of the innovation is going to happen server side, clients should be as dumb as possible. That is, it doesn't matter if a new state comes along after a client has shipped because it will be advertised as a potential transition (HATEOAS), perhaps even with the expected target state.
I totally agree.
The temptation is to assume that infrastructure is a simple problem with a fixed domain but I can assure you this not the case - without allowing for such flexibility each implementor will find themselves having a good chance of running into functions they are not able to expose via the API, or which the API expects but which are not present (for example, if "stop" implicitly results in "destroy" should we offer "stop" at all?).
My point was I wanted to talk about the "states as verbs" model which currently on the wiki ... Roger
Like it or not there will be rapid evolution in this space and you only need to look at what weird and wonderful things people like Google and Cisco are doing with hardware to realise that we pretty much don't know what we're talking about today let alone the life of the protocol.
Sam
Roger Menday (PhD) <roger.menday@uk.fujitsu.com> Senior Researcher, Fujitsu Laboratories of Europe Limited Hayes Park Central, Hayes End Road, Hayes, Middlesex, UB4 8FE, U.K. Tel: +44 (0) 208 606 4534 ______________________________________________________________________ Fujitsu Laboratories of Europe Limited Hayes Park Central, Hayes End Road, Hayes, Middlesex, UB4 8FE Registered No. 4153469 This e-mail and any attachments are for the sole use of addressee(s) and may contain information which is privileged and confidential. Unauthorised use or copying for disclosure is strictly prohibited. The fact that this e-mail has been scanned by Trendmicro Interscan and McAfee Groupshield does not guarantee that it has not been intercepted or amended nor that it is virus-free.