Unquote lambda functions. Add autoload cookies to functions formerly
[emacs.git] / lisp / url / url-methods.el
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1 ;;; url-methods.el --- Load URL schemes as needed
3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2004,
4 ;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
6 ;; Keywords: comm, data, processes, hypermedia
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 3, or (at your option)
13 ;; any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23 ;; Boston, MA 02110-1301, USA.
25 ;;; Commentary:
27 ;;; Code:
29 (eval-when-compile
30 (require 'cl))
32 ;; This loads up some of the small, silly URLs that I really don't
33 ;; want to bother putting in their own separate files.
34 (require 'url-parse)
36 (defvar url-scheme-registry (make-hash-table :size 7 :test 'equal))
38 (defconst url-scheme-methods
39 '((default-port . variable)
40 (asynchronous-p . variable)
41 (expand-file-name . function)
42 (file-exists-p . function)
43 (file-attributes . function)
44 (parse-url . function)
45 (file-symlink-p . function)
46 (file-writable-p . function)
47 (file-directory-p . function)
48 (file-executable-p . function)
49 (directory-files . function)
50 (file-truename . function))
51 "Assoc-list of methods that each URL loader can provide.")
53 (defconst url-scheme-default-properties
54 (list 'name "unknown"
55 'loader 'url-scheme-default-loader
56 'default-port 0
57 'expand-file-name 'url-identity-expander
58 'parse-url 'url-generic-parse-url
59 'asynchronous-p nil
60 'file-directory-p 'ignore
61 'file-truename (lambda (&rest args)
62 (url-recreate-url (car args)))
63 'file-exists-p 'ignore
64 'file-attributes 'ignore))
66 (defun url-scheme-default-loader (url &optional callback cbargs)
67 "Signal an error for an unknown URL scheme."
68 (error "Unkown URL scheme: %s" (url-type url)))
70 (defun url-scheme-register-proxy (scheme)
71 "Automatically find a proxy for SCHEME and put it in `url-proxy-services'."
72 (let* ((env-var (concat scheme "_proxy"))
73 (env-proxy (or (getenv (upcase env-var))
74 (getenv (downcase env-var))))
75 (cur-proxy (assoc scheme url-proxy-services))
76 (urlobj nil))
78 ;; If env-proxy is an empty string, treat it as if it were nil
79 (when (and (stringp env-proxy)
80 (string= env-proxy ""))
81 (setq env-proxy nil))
83 ;; Store any proxying information - this will not overwrite an old
84 ;; entry, so that people can still set this information in their
85 ;; .emacs file
86 (cond
87 (cur-proxy nil) ; Keep their old settings
88 ((null env-proxy) nil) ; No proxy setup
89 ;; First check if its something like hostname:port
90 ((string-match "^\\([^:]+\\):\\([0-9]+\\)$" env-proxy)
91 (setq urlobj (url-generic-parse-url nil)) ; Get a blank object
92 (setf (url-type urlobj) "http")
93 (setf (url-host urlobj) (match-string 1 env-proxy))
94 (setf (url-port urlobj) (string-to-number (match-string 2 env-proxy))))
95 ;; Then check if its a fully specified URL
96 ((string-match url-nonrelative-link env-proxy)
97 (setq urlobj (url-generic-parse-url env-proxy))
98 (setf (url-type urlobj) "http")
99 (setf (url-target urlobj) nil))
100 ;; Finally, fall back on the assumption that its just a hostname
102 (setq urlobj (url-generic-parse-url nil)) ; Get a blank object
103 (setf (url-type urlobj) "http")
104 (setf (url-host urlobj) env-proxy)))
106 (if (and (not cur-proxy) urlobj)
107 (progn
108 (setq url-proxy-services
109 (cons (cons scheme (format "%s:%d" (url-host urlobj)
110 (url-port urlobj)))
111 url-proxy-services))
112 (message "Using a proxy for %s..." scheme)))))
114 (defun url-scheme-get-property (scheme property)
115 "Get property of a URL SCHEME.
116 Will automatically try to load a backend from url-SCHEME.el if
117 it has not already been loaded."
118 (setq scheme (downcase scheme))
119 (let ((desc (gethash scheme url-scheme-registry)))
120 (if (not desc)
121 (let* ((stub (concat "url-" scheme))
122 (loader (intern stub)))
123 (condition-case ()
124 (require loader)
125 (error nil))
126 (if (fboundp loader)
127 (progn
128 ;; Found the module to handle <scheme> URLs
129 (url-scheme-register-proxy scheme)
130 (setq desc (list 'name scheme
131 'loader loader))
132 (dolist (cell url-scheme-methods)
133 (let ((symbol (intern-soft (format "%s-%s" stub (car cell))))
134 (type (cdr cell)))
135 (if symbol
136 (case type
137 (function
138 ;; Store the symbol name of a function
139 (if (fboundp symbol)
140 (setq desc (plist-put desc (car cell) symbol))))
141 (variable
142 ;; Store the VALUE of a variable
143 (if (boundp symbol)
144 (setq desc (plist-put desc (car cell)
145 (symbol-value symbol)))))
146 (otherwise
147 (error "Malformed url-scheme-methods entry: %S"
148 cell))))))
149 (puthash scheme desc url-scheme-registry)))))
150 (or (plist-get desc property)
151 (plist-get url-scheme-default-properties property))))
153 (provide 'url-methods)
155 ;; arch-tag: 336863f8-5a07-4906-9be5-b3c6bcebbe67
156 ;;; url-methods.el ends here