;; 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:
given either as a string, or as an XML tree, of a valid XHTML
fragment. See `atom-add-entry' for additional details.
-If CONVERT, translate all links in CONTENT so that they are no
-longer relative to LINK."
+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))
(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>"))
"Writes the feed ATOM to FILENAME."
(with-temp-buffer
(atom-print atom)
- (write-region (point-min) (point-max) filename)))
+ (write-file filename)))
\f
(defun atom-to-rss (atom)
(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)))
(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))))
"Saves ATOM as a RSS feed into FILENAME."
(with-temp-buffer
(atom-print-as-rss atom)
- (write-region nil nil filename)))
+ (write-file filename)))
\f
(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 string)
- (insert "</div>")
- (xml-parse-region (point-min) (point-max))))
+ (require 'xml-xhtml-entities)
+ (let ((xml-entity-alist xml-xhtml-entities)
+ (xml-validating-parser t))
+ (with-temp-buffer
+ (insert "<div xmlns=\"" atom-xhtml-namespace "\">")
+ (insert string)
+ (insert "</div>")
+ ;; `xml-parse-region' returns a list of elements, even though it
+ ;; requires an only root node. 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'."
(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
+implements Mark Pilgrom's tag: URI method, using the
+CREATION-DATE of the entry, and the domain part of LINK."
+ (format "tag:%s,%s:/%s"
+ (url-host (url-generic-parse-url link))
+ (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?
(file-name-directory (url-filename url-base))))
(url-recreate-url url-base))))
-(defun atom-generate-id (link creation-date)
- "Generate a string suitable for use as an atom:id element. This
-implements Mark Pilgrom's tag: URI method, using the
-CREATION-DATE of the entry, and the domain part of LINK."
- (format "tag:%s,%s:/%s"
- (url-host (url-generic-parse-url link))
- (format-time-string "%Y-%m-%d" creation-date)
- (format-time-string "%Y%m%d%H%M%S" creation-date)))
+(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