From 72e232fb4ae306f50cbc105a13f4bd7478f02b6f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fr=C3=A9d=C3=A9ric=20Perrin?= Date: Mon, 31 Jan 2011 00:07:52 +0100 Subject: [PATCH] Add the generation of the atom:id element. --- atom.el | 74 ++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 57 insertions(+), 17 deletions(-) diff --git a/atom.el b/atom.el index 694176d..42738e5 100644 --- a/atom.el +++ b/atom.el @@ -20,24 +20,53 @@ ;;; Commentary: -;; This is a library for creating an Atom file from a Lisp program. +;; This is a library for creating an Atom feed from a Lisp program. +;; The normal usage is to create a feed with `atom-create', giving it +;; a title and a Web address. Once the feed has been created, entries +;; may be added to the feed, by specifying (at the minimum) a title, a +;; 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. ;; A typical usage would look like this: ;; (let ((my-atom-feed (atom-create "My feed" "http://example.org"))) -;; (atom-add-text-entry my-atom-feed -;; "Hello world" -;; "http://example.org/hello" -;; "Hello the world!") -;; (atom-add-xhtml-entry my-atom-feed -;; "An XHTML example" -;; "http://example.org/html-example" -;; "

One can also use XHTML in the -;; entries.

") +;; ; A simple, text-only entry +;; (atom-add-text-entry +;; my-atom-feed +;; "Hello world" +;; "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" +;; "

One can also use XHTML in the entries.

") ;; (atom-print my-atom-feed)) + ;;; Code: +(require 'xml) + (defun atom-create (title link &optional author updated id) "Create a new atom structure. @@ -55,7 +84,6 @@ UPDATED is the date the feed was last updated. If not given, ID is a unique identifier for this feed. If not given, it defaults to LINK." - `((title nil ,title) (link ((href . ,link))) ,(atom-massage-author author) @@ -79,7 +107,7 @@ defaults to LINK." (nconc entry (list elem))))) (defun atom-add-entry (atom title link content - &optional summary updated id) + &optional updated id summary) "Add an entry to the atom flux ATOM. Return the newly added entry. @@ -96,9 +124,10 @@ If SUMMARY is not given, the entry will not contain any summary. UPDATED defaults to `(current-time)' if omitted, which is probably not a very good default. -ID defaults to LINK, which is not optimal; TODO give a way to -easily generate IDs. For a given entry, it must not change -between successive generations of the atom feed." +ID defaults to LINK, which is not optimal; see `atom-generate-id' +for a way to create good identifiers. For a given entry, it must +not change between successive generations of the atom feed, even +when the content of the entry ." (let ((entry (list (list 'title nil title)))) (atom-modify-entry entry 'link (list (list (cons 'href link)))) (atom-modify-entry entry 'id (or id link)) @@ -113,7 +142,7 @@ between successive generations of the atom feed." `atom-add-entry' for details.") (defun atom-add-html-entry (atom title link content - &optional summary updated id) + &optional updated id summary) "Add an entry to ATOM, with some HTML content. CONTENT should be a string enconding a valid HTML fragment. See `atom-add-entry' for additional details." @@ -124,7 +153,7 @@ for additional details." updated id)) (defun atom-add-xhtml-entry (atom title link content - &optional summary updated id) + &optional updated id summary) "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." @@ -189,5 +218,16 @@ Atom feed." (email nil ,(cadr author)))) (t `(author nil ,author)))) +(require 'url-parse) + +(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))) + (provide 'atom) ;;; atom.el ends here -- 2.43.0