;; permanent link and the content of the entry. Text-only, HTML and
;; XHTML entries are supported.
-;; A feed is really a Lisp structure as used by the `xml.el' package,
-;; without the parent `feed' element.
+;; It is possible to produce both Atom and RSS feeds.
;; A typical usage would look like this:
;; "http://example.org/hello"
;; "Hello the world!")
;;
-;; ; A text-only entry, with all the optional pieces of data
-;; (atom-add-text-entry
-;; my-atom-feed
-;; "Bonjour"
-;; "http://example.org/bonjour"
-;; "Bonjour à tout le monde !"
-;; ;; optional: the last modification time
-;; (date-to-time "2011-01-30 23:40:12")
-;; ;; optional: an identifier for this entry; a common way to generate it is
-;; ;; to use the domain name and the creation date of the entry.
-;; (atom-generate-id "http://example.org"
-;; (date-to-time "2011-01-30 10:01:05"))
-;; ;; optional: a summary for this entry
-;; "Bonjour, monde.")
-;;
;; (atom-add-xhtml-entry
;; my-atom-feed
;; "An XHTML example"
;; "http://example.org/html-example"
;; "<p>One can also use <acronym>XHTML</acronym> in the entries.</p>")
-;; (atom-print my-atom-feed))
+;;
+;; (atom-print my-atom-feed)
+;; ;; If you prefer RSS feeds:
+;; (atom-to-rss-print my-atom-feed))
+
+;; Full documentation is available at <http://tar-jx.bz/code/atom.html>.
;;; Code:
(require 'xml)
+(require 'url-parse)
+(require 'cl) ; for setf in url-canonalize
(defun atom-create (title link &optional subtitle self id author updated)
"Create a new atom structure.
defaults to SELF.
AUTHOR is the author of the feed. See `atom-massage-author' for
-the possible ways to specify it.
+the possible ways to specify it. In particular, `nil' uses
+`user-full-name' and `user-mail-address'.
UPDATED is the date the feed was last updated. If not given,
`(current-time)' is used."
updated id (and summary (atom-massage-html summary))))
(defun atom-add-xhtml-entry (atom title link content
- &optional updated id summary)
+ &optional updated id summary noconvert)
"Add an entry to ATOM, with some XHTML content. CONTENT may be
given either as a string, or as an XML tree, of a valid XHTML
-fragment. See `atom-add-entry' for additional details."
- (atom-add-entry atom
- title link (atom-massage-xhtml content)
- updated id (and summary (atom-massage-xhtml summary))))
+fragment. See `atom-add-entry' for additional details.
+
+If NOCONVERT is nil, translate all links in CONTENT so that they
+are no longer relative to LINK."
+ (let ((xhtml-content (atom-massage-xhtml content)))
+ (unless noconvert
+ (atom-xhtml-convert-links (cadr xhtml-content) link))
+ (atom-add-entry atom
+ title link xhtml-content
+ updated id (and summary (atom-massage-xhtml summary)))))
(defun atom-print (atom)
"Print the Atom feed ATOM in the current buffer."
- (insert "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n")
+ (insert atom-xml-declaration)
(insert "<feed xmlns=\"http://www.w3.org/2005/Atom\">\n")
(xml-print atom)
(insert "\n</feed>"))
(setcar (cdr guid) (list (cons 'isPermaLink "false"))))
(if (and descr
(equal (xml-get-attribute descr 'type) "xhtml"))
- (setcar (cddr descr) (xml-node-text descr))))
+ (setcar (cddr descr) (xml-node-as-text descr))))
`(item nil ,@item)))
(defun atom-to-rss-translator (source target translations)
(when data
(atom-modify-entry target to data)))))
-(defun xml-node-text (node)
- (with-temp-buffer
- (xml-print (xml-node-children node))
- (buffer-string)))
-
(defun atom-to-rss-modify-link (entry)
(let* ((link (assoc 'link entry))
(link-addr (xml-get-attribute-or-nil link 'href)))
- (message "%S" link)
(when link
(setcar (cdr link) nil)
(setcdr (cdr link) (cons link-addr nil)))))
(defun atom-print-as-rss (atom)
(let ((rss (atom-to-rss atom)))
- (insert "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n")
+ (insert atom-xml-declaration)
(insert "<rss version=\"2.0\">\n")
(insert " <channel>\n")
(xml-print rss " ")
(defun atom-to-rss-time (time)
"Translates a string from the format used by Atom into the
format used by RSS."
- ;; Same remark as in `atom-format-time'
(let ((system-time-locale "C"))
(format-time-string "%a, %d %b %Y %T %z" (atom-parse-time time))))
(defvar atom-time-format-string "%Y-%m-%dT%T%z"
"The format for string representation of dates.")
+(defvar atom-xhtml-namespace "http://www.w3.org/1999/xhtml")
+
+(defvar atom-xml-declaration "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n")
+
(defun atom-format-time (&optional time)
"Format a time according to RFC3339."
;; The time zone must be specified in numeric form, but with a colon between
(defun atom-parse-time (&optional time)
"Parse a time as specified in RFC3339 into Emacs's native format."
+ ;; Same remark as in `atom-format-time'
(date-to-time (replace-regexp-in-string ":\\(..\\)$" "\\1" time)))
(defun atom-massage-html (content)
(defun atom-string-to-xml (string)
"Convert STRING into a Lisp structure as used by `xml.el'."
(with-temp-buffer
- (insert "<div xmlns=\"http://www.w3.org/1999/xhtml\">")
+ (insert "<div xmlns=\"" atom-xhtml-namespace "\">")
(insert string)
(insert "</div>")
- (xml-parse-region (point-min) (point-max))))
+ ;; `xml-parse-region' doesn't require that the XML parsed be enclosed in a
+ ;; root node, and accordingly, returns a list of elements. We are only
+ ;; interested in the first one, the DIV we just inserted.
+ (car (xml-parse-region (point-min) (point-max)))))
(defun atom-massage-xhtml (content)
"Massage CONTENT so it can be used as an XHTML fragment in an
Atom feed."
- `(((type . "xhtml"))
- ,@(or (and (stringp content)
- (atom-string-to-xml content))
- content)))
+ (list '((type . "xhtml"))
+ (or (and (stringp content)
+ (atom-string-to-xml content))
+ `(div ((xmlns . ,atom-xhtml-namespace)) ,@content))))
(defun atom-massage-author (author)
"Return an XML node representing the author. AUTHOR can be:
- nil, in which case `user-full-name' and `user-mail-address' are
used;
-- a single string, the full name of the author;
+- a single string, the full name of the author; no email address
+ will be included;
- a list with two elements, the full name and the email address
of the author;
- something else, assumed to be a complete `atomPersonConstruct'."
(email nil ,(cadr author))))
(t `(author nil ,author)))))
-(require 'url-parse)
+(defun atom-xhtml-convert-links (node base)
+ "Make all links in NODE (a fragment of an XHTML document)
+absolute, in the context of BASE, an URL."
+ (dolist (attr-name (list 'href 'src))
+ (let ((attr (assoc attr-name (xml-node-attributes node))))
+ (when attr (setcdr attr (url-canonalize (cdr attr) base)))))
+ (dolist (child (xml-node-children node))
+ (when (listp child) (atom-xhtml-convert-links child base))))
(defun atom-generate-id (link creation-date)
"Generate a string suitable for use as an atom:id element. This
(format-time-string "%Y-%m-%d" creation-date)
(format-time-string "%Y%m%d%H%M%S" creation-date)))
+\f
+;;; Functions that should probably not be there
+
+(defun url-canonalize (address base)
+ "Make ADRESS an absolute URL, taking it in the BASE context."
+ ;; I feel such a function should exist in `url-parse'. Did I miss it?
+ (let ((url-base (url-generic-parse-url base))
+ (url-address (url-generic-parse-url address)))
+ (if (url-host url-address)
+ address
+ (setf (url-filename url-base)
+ (expand-file-name address
+ (file-name-directory (url-filename url-base))))
+ (url-recreate-url url-base))))
+
+(defun xml-node-as-text (node)
+ "Return a string representing NODE, an XML structure."
+ (with-temp-buffer
+ (xml-print (xml-node-children node))
+ (buffer-string)))
+
+(defun xml-node-create (name attrlist childlist)
+ "Create a new XML node."
+ (list name attrlist . childlist))
+
(provide 'atom)
;;; atom.el ends here
projects / atom.el.git / blobdiff