restcgi::version Class Reference

List of all members.

---

Detailed Description

Information that identifies a version of a resource.

Identification is with a version "tag" (version_tag) and/or a modification date-time. This version functionality connects resource modifications to the HTTP caching and operation contraint mechanisms. The version "tag" is used directly as the HTTP ETag, for example, in the ETag or If-None-Match header fields. The modification date is used in the Last-Modified and If-Modified-Since fields.

Applications should be designed to assign a verion tag to each resource modification.

For HTTP constraints to operate correctly, the application must send either the modification date and/or the tag when replying with resource content. Constraints can be checked automatically or explicitly by the application prior to responding to a method.

See also:

version_constraint, version_tag

Public Types
typedef restcgi::version_tag	tag_type
	tag type
typedef restcgi::date_time	date_time_type
	date-time type
Public Member Functions
	version ()
	Construct.
	version (const tag_type &tag, const date_time_type &dt=date_time_type())
	Construct.
	version (const date_time_type &dt, const tag_type &tag=tag_type())
	Construct.
bool	is_null () const
	Test if null.
const tag_type &	tag () const
	Get tag.
date_time_type	date_time () const
	Get modification date-time.

---