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| -rw-r--r-- | Makefile.am | 1 | ||||
| -rw-r--r-- | haunt/builder/rss.scm | 107 |
2 files changed, 108 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am index 1389cfb..b30753a 100644 --- a/Makefile.am +++ b/Makefile.am @@ -54,6 +54,7 @@ SOURCES = \ haunt/builder/assets.scm \ haunt/builder/atom.scm \ haunt/builder/blog.scm \ + haunt/builder/rss.scm \ haunt/reader.scm \ haunt/reader/texinfo.scm \ haunt/ui.scm \ diff --git a/haunt/builder/rss.scm b/haunt/builder/rss.scm new file mode 100644 index 0000000..1d988a7 --- /dev/null +++ b/haunt/builder/rss.scm @@ -0,0 +1,107 @@ +;;; Haunt --- Static site generator for GNU Guile +;;; Copyright © 2018 Christopher Lemmer Webber <cwebber@dustycloud.org> +;;; +;;; This file is part of Haunt. +;;; +;;; Haunt is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or +;;; (at your option) any later version. +;;; +;;; Haunt is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;;; General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with Haunt. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: +;; +;; RSS feed builder. +;; +;;; Code: + +(define-module (haunt builder rss) + #:use-module (srfi srfi-19) + #:use-module (srfi srfi-26) + #:use-module (ice-9 match) + #:use-module (sxml simple) + #:use-module (haunt site) + #:use-module (haunt post) + #:use-module (haunt page) + #:use-module (haunt utils) + #:use-module (haunt html) + #:use-module (haunt serve mime-types) + #:use-module (haunt builder atom) + #:export (rss-feed)) + +;; Reader beware: this isn't as nice as atom.scm, because rss isn't +;; as nice as atom. Worse beats better on the play field again... + +;; RFC 822 dates are inferior to ISO 8601, but it's +;; what RSS wants, so... +(define (date->rfc822-str date) + (date->string date "~a, ~d ~b ~Y ~T ~z")) + +(define (sxml->xml* sxml port) + "Write SXML to PORT, preceded by an <?xml> tag." + (display "<?xml version=\"1.0\" encoding=\"utf-8\"?>" port) + (sxml->xml sxml port)) + +(define* (post->rss-item site post #:key (blog-prefix "")) + "Convert POST into an RSS <item> node." + `(item + (title ,(post-ref post 'title)) + ;; Looks like: <author>lawyer@boyer.net (Lawyer Boyer)</author> + (author + ,(let ((email (post-ref post 'email)) + (author (post-ref post 'author))) + (string-append (if email + (string-append email " ") + "") + (if author + (string-append "(" author ")") + "")))) + (pubDate ,(date->rfc822-str (post-date post))) + (link (@ (href ,(string-append blog-prefix "/" + (site-post-slug site post) ".html")) + (rel "alternate"))) + (description ,(sxml->html-string (post-sxml post))) + ,@(map (lambda (enclosure) + `(enclosure (@ (title ,(enclosure-title enclosure)) + (url ,(enclosure-url enclosure)) + (type ,(enclosure-mime-type enclosure)) + ,@(map (match-lambda + ((key . value) + (list key value))) + (enclosure-extra enclosure))))) + (post-ref-all post 'enclosure)))) + +(define* (rss-feed #:key + (file-name "rss-feed.xml") + (subtitle "Recent Posts") + (filter posts/reverse-chronological) + (max-entries 20) + (blog-prefix "")) + "Return a builder procedure that renders a list of posts as an RSS +feed. All arguments are optional: + +FILE-NAME: The page file name +SUBTITLE: The feed subtitle +FILTER: The procedure called to manipulate the posts list before rendering +MAX-ENTRIES: The maximum number of posts to render in the feed" + (lambda (site posts) + (make-page file-name + `(rss (@ (version "2.0")) + (channel + (title ,(site-title site)) + ;; It looks like RSS's description and atom's subtitle + ;; are equivalent? + (description ,subtitle) + (pubDate ,(date->rfc822-str (current-date))) + (link (@ (href ,(site-domain site)))) + ,@(map (cut post->rss-item site <> + #:blog-prefix blog-prefix) + (take-up-to max-entries (filter posts))))) + sxml->xml*))) |