Re: Resource definition

On Tuesday, February 18, 2003, at 05:33  PM, Mark Baker wrote:

>
> On Tue, Feb 18, 2003 at 04:38:54PM -0800, Burdett, David wrote:
>> In an earlier email, Francis McCabe said ...
>>
>>>>> ... to use one of Mark's earlier examples, turning on a light 
>>>>> switch. The
>> state of the light is a representable resource; no question. The 
>> action of
>> flipping the switch is not so representable. The arm which is used to 
>> flip
>> the switch is, however, a resource; although any representation of it 
>> in
>> terms of bits is merely a symbol and not the real thing.<<<
>>
>> So is the act of moving the arm to turn on/off the switch a resource?
>
> Well, I suppose you could make it one, but I'm not sure what that
> would accomplish.
>
> One doesn't need to talk about a switch, or the movement of a switch, 
> or
> even a toggleSwitch() method, in order to effect a state change with 
> the
> bulb, because the interaction style is one of *state transfer*; if I
> want to turn the bulb on, I just do a HTTP PUT containing a
> representation of the "on state" to the URI identifying the lightbulb.
>

This is NOT correct. (IMHO)

First of all, there are any number of actions which cannot be 
represented by an update in the state; especially in any state that is 
accessible to the requestor!

Secondly, simply telling the resource that the light is on is not 
equivalent to actually switching the switch!

Frank