- From: Yves Lafon <ylafon@w3.org>
- Date: Fri, 14 Nov 2008 14:31:26 -0500 (EST)
- To: ietf-http-wg@w3.org
Here is a proposed change for issue #101 [1], as the issue is more the definition of "weak validator", being linked to both unreliable identification of changes _and_ the will to signal only significant (read: semantic) changes. In paragraph 5 of Part 4 [2], change: However, there might be cases when a server prefers to change the validator only on semantically significant changes, and not when insignificant aspects of the entity change. A validator that does not always change when the resource changes is a "weak validator." Entity tags are normally "strong validators," but the protocol provides a mechanism to tag an entity tag as "weak." One can think of a strong validator as one that changes whenever the bits of an entity changes, while a weak value changes whenever the meaning of an entity changes. Alternatively, one can think of a strong validator as part of an identifier for a specific entity, while a weak validator is part of an identifier for a set of semantically equivalent entities. => However, there might be cases when a server prefers to change the validator only on semantically significant changes, and not when insignificant aspects of the entity change, or cases where the validator is use does not allow reliable identification of changes. A validator that does not always change when the resource changes is a "weak validator". Entity tags are normally "strong validators", but the protocol provides a mechanism to tag an entity tag as "weak". One can think of a strong validator as one that changes whenever the bits of an entity changes, while a weak entity tag value changes whenever the meaning of an entity changes. Alternatively, one can think of a strong validator as part of an identifier for a specific entity, while an entity tag used as a weak validator is part of an identifier for a set of semantically equivalent entities. Thoughts? [1] <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/101> [2] <http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-04#section-5> -- Baroula que barouleras, au tiéu toujou t'entourneras. ~~Yves
Received on Friday, 14 November 2008 19:31:36 UTC