source: project/wiki/eggref/4/uri-common @ 15220

Last change on this file since 15220 was 15220, checked in by sjamaan, 10 years ago

Oops, uri-common, not uri-generic :)

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1[[tags: eggs]]
2[[toc:]]
3
4== uri-common
5
6=== Description
7
8The {{uri-common}} library provides simple and easy-to-use parsing
9and manipulation procedures for URIs using common schemes.
10
11These "common schemes" all have the following rules:
12
13* An empty path after the hostname is considered to be identical to the root path.
14* All components are to be fully URI-decoded (so no percent-encoded characters in it).
15* The query argument will be in
16   [[http://www.w3.org/TR/xforms/#structure-model-submission|application/x-www-form-urlencoded]] form.
17* The port is automatically determined if it is omitted and the URI scheme is known.
18
19=== Library Procedures
20
21This library replaces most of the procedures in [[uri-generic]]. If
22you need to work with URIs on the uri-generic level or need to work
23with both uri-generic and uri-common URI objects, you will have to
24import and prefix or rename procedures.
25
26==== Constructors and predicates
27
28These constructors fully decode their arguments, so afterwards it is
29impossible to distinguish between encoded delimiters and unencoded
30delimiters.  This makes uri-common objects decoding endpoints; no
31further decoding on the URI level is possible (of course, applications
32are free to decode further information inside the URI).  If for some
33reason, the original URI is still needed, it can be converted to a
34uri-generic.  However, updating a URI component causes this
35component's original encoding to be lost, so be careful!
36
37<procedure>(uri-reference STRING) => URI</procedure>
38
39A URI reference is either a URI or a relative reference (RFC 3986,
40Section 4.1).  If the given string's prefix does not match the syntax
41of a scheme followed by a colon separator, then the given string is
42parsed as a relative reference.
43
44<procedure>(uri-reference? URI) => BOOL</procedure>
45
46Is the given object a URI reference?  '''All objects created by
47URI-common constructors are URI references'''; they are either URIs
48or relative references.  The constructors below are just more strict
49checking versions of {{uri-reference}}.  They all create
50URI references.
51
52<procedure>(absolute-uri STRING) => URI</procedure>
53
54Parses the given string as an absolute URI, in which no fragments are
55allowed.  If no URI scheme is found, or a fragment is detected, this
56raises an error.
57
58Absolute URIs are defined by RFC 3986 as non-relative URI references
59without a fragment (RFC 3986, Section 4.2).  Absolute URIs can be used
60as a base URI to resolve a relative-ref against, using
61{{uri-relative-to}} (see below).
62
63<procedure>(absolute-uri? URI) => BOOL</procedure>
64
65Is the given object an absolute URI?
66
67<procedure>(uri? URI) => BOOL</procedure>
68
69Is the given object a URI?  URIs are all URI references that include
70a scheme part.  The other type of URI references are relative
71references.
72
73<procedure>(relative-ref? URI) => BOOL</procedure>
74
75Is the given object a relative reference?  Relative references are
76defined by RFC 3986 as URI references which are not URIs; they contain
77no URI scheme and can be resolved against an absolute URI to obtain
78a complete URI using {{uri-relative-to}}.
79
80<procedure>(uri-path-absolute? URI) => BOOL</procedure>
81
82Is the {{URI}}'s path component an absolute path?
83
84<procedure>(uri-path-relative? URI) => BOOL</procedure>
85
86Is the {{URI}}'s path component a relative path?
87
88<procedure>(uri-default-port? URI) => BOOL</procedure>
89
90Is the {{URI}}'s port the default port for the {{URI}}'s scheme?
91
92==== uri-generic, string and list representation
93
94<procedure>(uri->uri-generic uri-common) => uri-generic</procedure>
95<procedure>(uri-generic->uri uri-common) => uri-common</procedure>
96
97To convert between uri-generic and uri-common objects, use these
98procedures.  As stated above, this will allow you to retrieve the
99original encoding of the URI components, but once you update a
100component from the uri-common side, the original encoding is no longer
101available (the updated value replaces the original value).
102
103<procedure>(uri->string uri-common userinfo) => string</procedure>
104
105Reconstructs the given URI into a string; uses a supplied function
106{{LAMBDA USERNAME PASSWORD -> STRING}} to map the userinfo part of the
107URI.
108
109<procedure>(uri->list URI USERINFO) => LIST</procedure>
110
111Returns a list of the form {{(SCHEME SPECIFIC FRAGMENT)}};
112{{SPECIFIC}} is of the form {{(AUTHORITY PATH QUERY)}}.
113
114
115==== Accessors
116
117* <procedure>(uri-scheme uri-common) => symbol</procedure>
118* <procedure>(uri-path uri-common) => list</procedure>
119* <procedure>(uri-query uri-common) => alist</procedure>
120* <procedure>(uri-fragment uri-common) => string</procedure>
121* <procedure>(uri-host uri-common) => string</procedure>
122* <procedure>(uri-port uri-common) => integer</procedure>
123* <procedure>(uri-username uri-common) => string</procedure>
124* <procedure>(uri-password uri-common) => string</procedure>
125
126If a component is not defined in the given URI-common, then the
127corresponding accessor returns {{#f}}.
128
129* <procedure>(update-uri URI-common #!key scheme path query fragment host port username password) => URI-common</procedure>
130
131Update the specified keys in the URI-common object in a functional way
132(ie, it creates a new copy with the modifications).
133
134==== Reference Resolution
135
136<procedure>(uri-relative-to URI URI) => URI</procedure>
137
138Resolve the first URI as a reference relative to the second URI,
139returning a new URI (RFC 3986, Section 5.2.2).
140
141<procedure>(uri-relative-from URI URI) => URI</procedure>
142
143Constructs a new, possibly relative, URI which represents the location
144of the first URI with respect to the second URI.
145
146<examples>
147<example>
148<init>(use uri-common)</init>
149<expr>(uri->string (uri-relative-to (uri-reference "../qux") (uri-reference "http://example.com/foo/bar/")))</expr>
150<result>"http://example.com/foo/qux"</result>
151</example>
152<example>
153<init>(use uri-common)</init>
154<expr>(uri->string (uri-relative-from (uri-reference "http://example.com/foo/qux") (uri-reference "http://example.com/foo/bar/")))</expr>
155<result>"../qux"</result>
156</example>
157</examples>
158
159==== Query encoding and decoding
160
161* <parameter>(form-urlencoded-separator [char-set/char/string])</parameter>
162* <procedure>(form-urlencode alist #!key (separator (form-urlencoded-separator))) => string</procedure>
163* <procedure>(form-urldecode string #!key (separator (form-urlencoded-separator))) => alist</procedure>
164
165Encode or decode an alist using the encoding corresponding to the
166[[http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1|form-urlencoded]]
167media type, using the given separator character(s).
168
169When encoding, if {{separator}} is a string, the first character will
170be used as the separator in the resulting querystring.  If it is a
171char-set, it will be converted to a string and its first character
172will be taken.  In either case, all of these characters are encoded if
173they occur inside the key/value pairs.
174
175When decoding, any character in the set (or string) will be seen as
176a separator.
177
178The separator defaults to the string {{";&"}}.  This means that
179either semicolons or ampersands are allowed as separators when decoding
180an URI string, but semicolons are used when generating strings.
181
182If you would like to use a different separator, you should parameterize
183''all'' calls to procedures that return an uri-common object.
184
185
186==== Normalization 
187
188<procedure>(uri-normalize-case URI) => URI</procedure>
189
190URI case normalization (RFC 3986 section 6.2.2.1)
191
192<procedure>(uri-normalize-path-segments URI) => URI</procedure>
193
194URI path segment normalization (RFC 3986 section 6.2.2.3)
195
196
197=== Requires
198
199* [[uri-generic]]
200* [[matchable]]
201* [[defstruct]]
202
203=== Version History
204
205* 0.7 Fix silly bug in the predicates from 0.6 (it helps to test first...)
206* 0.6 Add predicates uri-path-relative? and uri-path-absolute?
207* 0.5 Add {{uri-default-port?}} predicate procedure
208* 0.4 Add {{uri->list}} conversion procedure
209* 0.3 Fix dependency info (requires at least uri-generic 2.1)
210* 0.2 Add predicates for URIs, absolute URIs and relative references, matching the ones in uri-generic.
211* 0.1 Initial Release
212
213=== License
214
215  Copyright 2008-2009 Peter Bex
216  All rights reserved.
217 
218  Redistribution and use in source and binary forms, with or without
219  modification, are permitted provided that the following conditions are
220  met:
221 
222  Redistributions of source code must retain the above copyright
223  notice, this list of conditions and the following disclaimer.
224 
225  Redistributions in binary form must reproduce the above copyright
226  notice, this list of conditions and the following disclaimer in the
227  documentation and/or other materials provided with the distribution.
228 
229  Neither the name of the author nor the names of its contributors may
230  be used to endorse or promote products derived from this software
231  without specific prior written permission.
232 
233  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
234  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
235  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
236  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
237  COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
238  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
239  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
240  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
241  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
242  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
243  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
244  OF THE POSSIBILITY OF SUCH DAMAGE.
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