> Thanks John for the great feedback. > > > On the source account, you'd initiate a transfer with the arguments > > being the target account and the amount. The result on > success would > > be that specific transfer's ID. > > Ah, but you're not saying how you 'initiate a transfer'. It's > one of the questions I'm struggling with. It could be: > ... > POST /transfer/account/123 > Host: myserver.com > Content-Length: XXX > <toAccount>456</toAccount> > <amount>300</amount> > > The problem I have with the first approach is that I'm still > passing an action, i.e. doing some kind of RPC. My > understanding is that in a 'pure' RESTful API the only way to > specify the action is via the HTTP method (get,post,put,delete). > The second solution seems even worse as it mixes the action > with the resource.
It *seems* like you're passing an action, but IMO what you're actually doing is turning the action into a resource, which is very powerful. That resource has a unique address, a state that can be transferred, and is only manipulated with our four magic verbs. You can even make it asynchronous by posting a transaction and polling for its status later at the resource's URL. There was actually a useful post about this sort of approach on rest-discuss a couple days ago: http://tech.groups.yahoo.com/group/rest-discuss/message/6561 > And what if I want to close all accounts that have been > inactive for at least a year, without retrieving them one by one? > Would this approach: > > POST /account/?inactivityPeriod=365 > Host: myserver.com > Content-Length: XXX > <action>close</action> > > be more appropriate than this one? > POST /account/ > Host: myserver.com > Content-Length: XXX > <action>closeInactive</action> > <inactivityPeriod>365</inactivityPeriod> If you don't want to retrieve them one by one I think you can do the same thing, invert an action into a resource with something like: GET /accounts/?inactivityPeriod=365 You get back a set of account URLs: <accounts> <account link="/account/1234" /> <account link="/account/1235" /> <account link="/account/1236" /> </accounts> Which maybe you can POST to an 'account closing' resource: >> POST /account-closer <accounts> <account link="/account/1234" /> <account link="/account/1235" /> <account link="/account/1236" /> </accounts> << 201 Created Location: /account-transaction/2006-09-18-A >> GET /account-transaction/2006-09-18-A << 200 OK <transaction status="Closed"> <resources> <account link="/account/1234" /> <account link="/account/1235" /> <account link="/account/1236" /> </resources> </transaction> Since that's a separate resource, you can ask questions of it, like find the most recent transactions: GET /account-transaction/recent Or whatever. I'm pretty sure this isn't gospel, but it makes sense to me, and I think demonstrates the power of the 'resource' abstraction. Chris
