From: Jason S. Lingohr Date: Sat, 20 Sep 2003 10:02:52 +0000 (+0000) Subject: Sync and transformation update. X-Git-Tag: 2.0.48~53 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=894c23adb89f7eeb6c4605d7da87f81cbd230fb0;p=thirdparty%2Fapache%2Fhttpd.git Sync and transformation update. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@101299 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/manual/content-negotiation.html.en b/docs/manual/content-negotiation.html.en index 343ed4a2117..7e55a62ac9c 100644 --- a/docs/manual/content-negotiation.html.en +++ b/docs/manual/content-negotiation.html.en @@ -24,7 +24,7 @@ -

Apache's supports content negotiation as described in +

Apache supports content negotiation as described in the HTTP/1.1 specification. It can choose the best representation of a resource based on the browser-supplied preferences for media type, languages, character set and @@ -33,8 +33,8 @@ incomplete negotiation information.

Content negotiation is provided by the - mod_negotiation module. - which is compiled in by default.

+ mod_negotiation module, which is compiled in + by default.

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Note on hyperlinks and naming conventions

diff --git a/docs/manual/content-negotiation.xml b/docs/manual/content-negotiation.xml index c0553351100..f04f2b63388 100644 --- a/docs/manual/content-negotiation.xml +++ b/docs/manual/content-negotiation.xml @@ -7,7 +7,7 @@ -

Apache's supports content negotiation as described in +

Apache supports content negotiation as described in the HTTP/1.1 specification. It can choose the best representation of a resource based on the browser-supplied preferences for media type, languages, character set and @@ -16,8 +16,8 @@ incomplete negotiation information.

Content negotiation is provided by the - mod_negotiation module. - which is compiled in by default.

+ mod_negotiation module, which is compiled in + by default.
About Content Negotiation @@ -28,7 +28,7 @@ One way of selecting the most appropriate choice is to give the user an index page, and let them select. However it is often possible for the server to choose automatically. This works - because browsers can send as part of each request information + because browsers can send, as part of each request, information about what representations they prefer. For example, a browser could indicate that it would like to see information in French, if possible, else English will do. Browsers indicate their @@ -54,11 +54,12 @@

Apache supports 'server driven' content negotiation, as defined in the HTTP/1.1 specification. It fully supports the - Accept, Accept-Language, Accept-Charset and Accept-Encoding + Accept, Accept-Language, + Accept-Charset andAccept-Encoding request headers. Apache also supports 'transparent' content negotiation, which is an experimental negotiation protocol defined in RFC 2295 and RFC 2296. It does not offer - support for 'feature negotiation' as defined in these RFCs.

+ support for 'feature negotiation' as defined in these RFCs.

A resource is a conceptual entity identified by a URI (RFC 2396). An HTTP server like Apache @@ -95,11 +96,13 @@

A type map is a document which is associated with the handler named type-map (or, for backwards-compatibility with older Apache configurations, the - mime type application/x-type-map). Note that to + MIME type application/x-type-map). Note that to use this feature, you must have a handler set in the configuration that defines a file suffix as - type-map; this is best done with a

+ type-map; this is best done with

+ AddHandler type-map .var +

in the server configuration file.

Type map files should have the same name as the resource @@ -128,7 +131,7 @@ filename's extension, even when Multiviews is on. If the variants have different source qualities, that may be indicated by the "qs" parameter to the media type, as in this picture - (available as jpeg, gif, or ASCII-art):

+ (available as JPEG, GIF, or ASCII-art):

URI: foo
@@ -148,11 +151,11 @@ Variants with no 'qs' parameter value are given a qs factor of 1.0. The qs parameter indicates the relative 'quality' of this variant compared to the other available variants, independent - of the client's capabilities. For example, a jpeg file is - usually of higher source quality than an ascii file if it is + of the client's capabilities. For example, a JPEG file is + usually of higher source quality than an ASCII file if it is attempting to represent a photograph. However, if the resource - being represented is an original ascii art, then an ascii - representation would have a higher source quality than a jpeg + being represented is an original ASCII art, then an ASCII + representation would have a higher source quality than a JPEG representation. A qs value is therefore specific to a given variant depending on the nature of the resource it represents.

@@ -252,35 +255,36 @@ Media Type - Browser indicates preferences with the Accept header - field. Each item can have an associated quality factor. - Variant description can also have a quality factor (the - "qs" parameter). + Browser indicates preferences with the Accept + header field. Each item can have an associated quality factor. + Variant description can also have a quality factor (the "qs" + parameter). Language - Browser indicates preferences with the Accept-Language - header field. Each item can have a quality factor. Variants - can be associated with none, one or more than one - language. + Browser indicates preferences with the + Accept-Language header field. Each item can have + a quality factor. Variants can be associated with none, one or + more than one language. Encoding - Browser indicates preference with the Accept-Encoding - header field. Each item can have a quality factor. + Browser indicates preference with the + Accept-Encoding header field. Each item can have + a quality factor. Charset - Browser indicates preference with the Accept-Charset - header field. Each item can have a quality factor. Variants - can indicate a charset as a parameter of the media - type. + Browser indicates preference with the + Accept-Charset header field. Each item can have a + quality factor. Variants can indicate a charset as a parameter + of the media type.
@@ -307,8 +311,8 @@ move on to the next test.
    -
  1. Multiply the quality factor from the Accept header - with the quality-of-source factor for this variant's +
  2. Multiply the quality factor from the Accept + header with the quality-of-source factor for this variants media type, and select the variants with the highest value.
    3. @@ -317,20 +321,20 @@
  3. Select the variants with the best language match, using either the order of languages in the - Accept-Language header (if present), or else the order of - languages in the LanguagePriority directive - (if present).
    4. + Accept-Language header (if present), or else + the order of languages in the LanguagePriority + directive (if present).
  4. Select the variants with the highest 'level' media parameter (used to give the version of text/html media types).
  5. Select variants with the best charset media - parameters, as given on the Accept-Charset header line. - Charset ISO-8859-1 is acceptable unless explicitly - excluded. Variants with a text/* media type - but not explicitly associated with a particular charset - are assumed to be in ISO-8859-1.
    6. + parameters, as given on the Accept-Charset + header line. Charset ISO-8859-1 is acceptable unless + explicitly excluded. Variants with a text/* + media type but not explicitly associated with a particular + charset are assumed to be in ISO-8859-1.
  6. Select those variants which have associated charset media parameters that are not ISO-8859-1. If @@ -357,17 +361,17 @@
  7. The algorithm has now selected one 'best' variant, so - return it as the response. The HTTP response header Vary is - set to indicate the dimensions of negotiation (browsers and - caches can use this information when caching the resource). - End.
    8. + return it as the response. The HTTP response header + Vary is set to indicate the dimensions of + negotiation (browsers and caches can use this information when + caching the resource). End.
  8. To get here means no variant was selected (because none are acceptable to the browser). Return a 406 status (meaning "No acceptable representation") with a response body consisting of an HTML document listing the available - variants. Also set the HTTP Vary header to indicate the - dimensions of variance.
    9. + variants. Also set the HTTP Vary header to + indicate the dimensions of variance.
@@ -380,16 +384,16 @@ negotiation algorithm above. This is to get a better result from the algorithm for browsers which do not send full or accurate information. Some of the most popular browsers send - Accept header information which would otherwise result in the - selection of the wrong variant in many cases. If a browser - sends full and correct information these fiddles will not be - applied.

+ Accept header information which would otherwise + result in the selection of the wrong variant in many cases. If a + browser sends full and correct information these fiddles will not + be applied.

Media Types and Wildcards -

The Accept: request header indicates preferences for media - types. It can also include 'wildcard' media types, such as - "image/*" or "*/*" where the * matches any string. So a request +

The Accept: request header indicates preferences + for media types. It can also include 'wildcard' media types, such + as "image/*" or "*/*" where the * matches any string. So a request including:

Accept: image/*, */* @@ -414,14 +418,14 @@ low preference of 0.01, so other types will only be returned if no variant matches an explicitly listed type.

-

If the Accept: header contains no q factors at all, - Apache sets the q value of "*/*", if present, to 0.01 to - emulate the desired behavior. It also sets the q value of - wildcards of the format "type/*" to 0.02 (so these are - preferred over matches against "*/*". If any media type on the - Accept: header contains a q factor, these special values are - not applied, so requests from browsers which send the - explicit information to start with work as expected.

+

If the Accept: header contains no q + factors at all, Apache sets the q value of "*/*", if present, to + 0.01 to emulate the desired behavior. It also sets the q value of + wildcards of the format "type/*" to 0.02 (so these are preferred + over matches against "*/*". If any media type on the + Accept: header contains a q factor, these special + values are not applied, so requests from browsers which + send the explicit information to start with work as expected.

Language Negotiation Exceptions @@ -431,15 +435,17 @@ negotiation fails to find a match.

When a client requests a page on your server, but the server - cannot find a single page that matches the Accept-language sent by + cannot find a single page that matches the + Accept-language sent by the browser, the server will return either a "No Acceptable Variant" or "Multiple Choices" response to the client. To avoid these error messages, it is possible to configure Apache to ignore - the Accept-language in these cases and provide a document that - does not explicitly match the client's request. The Accept-language in these cases and provide a + document that does not explicitly match the client's request. The + ForceLanguagePriority directive can be used to override one or both of these error - messages and substitute the servers judgement in the form of the + messages and substitute the servers judgement in the form of the LanguagePriority directive.

@@ -450,11 +456,11 @@ standard to match that against a document that is marked as simply en. (Note that it is almost surely a configuration error to include en-GB and not en in the - Accept-Language header, since it is very unlikely that a reader - understands British English, but doesn't understand English in - general. Unfortunately, many current clients have default - configurations that resemble this.) However, if no other language - match is possible and the server is about to return a "No + Accept-Language header, since it is very unlikely + that a reader understands British English, but doesn't understand + English in general. Unfortunately, many current clients have + default configurations that resemble this.) However, if no other + language match is possible and the server is about to return a "No Acceptable Variants" error or fallback to the LanguagePriority, the server will ignore the subset specification and match en-GB @@ -467,7 +473,7 @@ specification and to work effectively with properly configured clients.

-

In order to support advanced techniques (such as Cookies or +

In order to support advanced techniques (such as cookies or special URL-paths) to determine the user's preferred language, since Apache 2.0.47 mod_negotiation recognizes the environment variable @@ -492,9 +498,9 @@ variant lists to label variants which are available with a specific content-encoding only. The implementation of the RVSA/1.0 algorithm (RFC 2296) is extended to recognize encoded variants in the list, and to use them as candidate variants whenever their encodings are -acceptable according to the Accept-Encoding request header. The -RVSA/1.0 implementation does not round computed quality factors to 5 -decimal places before choosing the best variant.

+acceptable according to the Accept-Encoding request +header. The RVSA/1.0 implementation does not round computed quality +factors to 5 decimal places before choosing the best variant.

Note on hyperlinks and naming conventions