[1] Resource and Representation Typing in HTTP HTTP における資源及び表現型付け
This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026.
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This Internet-draft will expire on September 1, 2002.
Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. (ママ)
This document defines the "Repr-Type" and "Resource-Type" HTTP entity-header field names, to provide URIs that identify the generic type (class membership) of representations and their original source resources respectively.
この文書は、 HTTP
実体頭欄名
Repr-Type
及び Resource-Type
を定義します。
これらは、表現の一般的な型 (class
membership) とその元の典拠資源をそれぞれ識別する
URI を提供します。
Providing a resource type along with an HTTP response is useful, since there may be no other way to identify the resource type within the domain of the HTTP message. For example, HTML pages do not give a machine processable type for the resource that they are representations of.
資源の型を HTTP 応答と共に提供することは有用です。 なぜなら、 HTTP メッセージの範囲内で資源の型を識別する方法は他にはおそらくないからです。 たとえば、 HTML 頁はその表現している資源の機械が処理可能な型を与えません。
Meanwhile, using MIME types to identify content types is architecturally inadvisable due to the centralization around the IANA - URIs should identify all important things on the Web, and content types are no exception. (Note that the current set of MIME types can have URIs, and those can be used in the Repr-Type header).
他方、 MIME型を使って内容型を識別することは、
IANA で中央管理されているので構造的には不適当です。
URI は Web
のすべての重要なものを識別でき、
内容型も例外ではありません。
(現在の MIME 型の集合は URI
を持ち得て、これらは
Repr-Type
頭で使用し得ることに注意。)
In fact, the content type idiom is isomorphic with that of the "Class" class in RDF Schema [RDFSchema].
実際、内容型慣用句は RDFSchema
の Ckass class
と isomorphic です。
RDF classes can be defined to represent almost anything, such as Web pages, people, document types, databases or abstract concepts. <http://www.w3.org/TR/2000/CR-rdf-schema-20000327/#s2.2.3>
RDF class は、 Web頁, 人物, 文書型, データベース, 抽象概念などほとんどなんでも表現するように定義できます。
Repr-Type values are generally restricted to content type classes, whereas the Resource-Type value have no such restriction, according to the definition of resource in RFC 2396.
Repr-Type 値は通常内容型
class に制限されます。
Resource-Type
値は、 RFC2396
の資源の定義に従ってそうした制限はありません。
Here is an ABNF for the proposed entity-headers:-
これは提案する実態頭の ABNF です:
- ResourceType = "Resource-Type" ":" 1#URIview
- ReprType = "Repr-Type" ":" 1#URIview
- URIview = absoluteURI [ "#" fragment ] ; from [RFC2396]
The <absoluteURI>, and <fragment> components are imported from [RFC2396].
absoluteURI,
fragment
は RFC 2396 から輸入しました。
Two examples of syntactically valid ResourceType productions (i.e. "Resource-Type" HTTP headers) are:-
構文的に妥当な
ResourceType 生成物
(すなわち
Resource-Type
HTTP 頭) の2つの例は:
- Resource-Type: http://xmlns.com/foaf/0.1/Person
- Resource-Type: http://www.w3.org/2000/10/swap/pim/doc#Work
Two examples of syntactically valid ReprType productions (i.e. "Repr-Type" HTTP headers) are:-
構文的に妥当な
ReprType 生成物
(すなわち
Repr-Type
HTTP 頭) の2つの例は:
- Repr-Type: http://www.w3.org/2000/10/swap/log#N3Document
- Repr-Type: http://www.iana.org/assignments/media-types/text/html
Header values are to be compared on a character for character (case sensitive) basis. Due to internationalization issues, escaped unicode characters are allowed in the URI header values. You must use the following escaping procedure:-
頭値は文字ごとに (大文字・小文字を区別して) 比較します。 国際化の問題から、 escape した unicode 文字は URI 頭値中で認められます。 次の escape 手続きを踏まなければなりません。
- Each disallowed character is converted to UTF-8 (as defined in [RFC2279]) as one or more bytes.
- Any bytes corresponding to a disallowed character are escaped with the URI escaping mechanism (that is, converted to %HH, where HH is the hexadecimal notation of the byte value).
- The original character is replaced by the resulting character sequence.
It is perfectly legal and sensible for either of the defined entity-headers to occur more than once; if they do, then processors should take the intersection of the given classes. For example, a Resource Type may be both Vehicle and a Car. A Representation Type may be both an XML document, and a canonicalized XML document.
定義された実体頭を複数回出現させることはまったく合法であって意味のあることです。 そうした場合、処理系は与えられた class の相互作用と取るべきです。 たとえば、資源型は Vehicle 及び車の双方かもしれません。 表現型は XML 文書と正規化 XML 文書の双方かもしれません。
Note that if the Repr-Type (and possibly Content-Type) headers conflict semantically, then all of the Repr-Type headers (or just those that conflict with Content-Type, if present) should be abandoned.
Repr-Type
(及びもしかすると Content-Type)
頭が意味的に衝突する場合は、
すべての Repr-Type
頭 (あるいは Content-Type
と衝突する場合は単にそれと衝突するもの)
は捨てるべきです。
Implementors should take heed of section 15.1.1 of [RFC2616]. There may be other security considerations that have not yet been raised.
実装者は RFC2616 の 15.1.1 節に注意するべきです。 まだ起こっていない他の安全上の注意点もあるかもしれません。
The relevant security issues associated with each Repr-Type value should obviously be taken into consideration when handling the entity-body.
Further information on the headers defined by this document is available at <http://purl.org/net/resreptype>
この文書の定義する頭についての詳しい情報は <http://purl.org/net/resreptype> から入手可能です。
Many thanks to Mark Baker, Tim Berners-Lee, Jonathan Borden, Sandro Hawke, Mark Nottingham, and Aaron Swartz for the discussions and inspiration that led to this document.
Many thanks also to Daniel Biddle and Aaron Swartz for their help in preparing this document.
[RDFSchema] Dan Brickley, R. V. Guha (2000). Resource Description
Framework (RDF) Schema Specification 1.0. W3C Candidate
Recommendation.
http://www.w3.org/TR/2000/CR-rdf-schema-20000327/ [RFC2279] F. Yergeau (1998). UTF-8, a transformation format of
ISO 10646.
http://www.ietf.org/rfc/rfc2279.txt [RFC2396] T. Berners-Lee, R. Fielding, L. Masinter (1998). Uniform
Resource Identifiers (URI): Generic Syntax.
http://www.ietf.org/rfc/rfc2279.txt [RFC2616] T. Berners-Lee, R. Fielding, H. Frystyk, J. Gettys, P.
Leach, L. Masinter, J. Mogul (1999). Hypertext Transfer
Protocol -- HTTP/1.1.
http://www.ietf.org/rfc/rfc2616.txt
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