RE: How Clients find out if they can perform a checkout

   From: Stefan Eissing [mailto:stefan.eissing@greenbytes.de]

   > From: Geoff Clemm
   > ... in general "supported" means that the method might succeed on
   > some state of the resource, while the Allow set indicates whether
   > the method might succeed on the current state of the resource.  I
   > agree this is worth stating in the protocol (if people agree with
   > this characterization).

   Oh, let's not be too subtle in DeltaV, please.

   From RFC 2616, Ch. 14.7 "Allow", first sentence:
   "The Allow entity-header field lists the set of methods supported by the
   resource identified by the Request-URI."

   Now, how could that be different from a "supported-method-set"?

You need to look at the other sections of RFC 2616 that discuss Allow.
In particular, in section 5.1.1:

   The list of methods allowed by a resource can be specified in an
   Allow header field (section 14.7). The return code of the response
   always notifies the client whether a method is currently allowed on
   a resource, since the set of allowed methods can change
   dynamically.

I believe this makes it clear that "allow" means "might succeed on the
current state of the resource" as opposed to "might succeed on some
state of the resource".  This distinction is very important, because
the latter would probably be used to determine what the menu for that
resource would contain, while the former would be used to determine
which entries in this menu should be "greyed out".

Cheers,
Geoff

Received on Tuesday, 24 July 2001 12:57:03 UTC