atom/rss: Allow passing last updated date for reproducibility.

3 files changed, 24 insertions, 2 deletions

diff --git a/doc/haunt.texi b/doc/haunt.texi
index d19cf71..6be2fb5 100644
--- a/doc/haunt.texi
+++ b/doc/haunt.texi
@@ -997,6 +997,7 @@ The default theme is intended only for testing purposes.
 
 @deffn {Procedure} atom-feed [#:file-name "feed.xml"] [#:subtitle "Recent Posts"] @
                              [#:filter posts/reverse-chronological] @
+                             [#:last-updated (current-date)] @
                              [#:max-entries 20] [#:blog-prefix ""]
 Return a builder procedure that renders a site's posts as an Atom
 feed.  All arguments are optional:
@@ -1012,6 +1013,9 @@ The feed subtitle.
 @item filter
 The procedure called to manipulate the posts list before rendering.
 
+@item last-updated
+The feed last updated date.  Defaults to the current date.
+
 @item max-entries
 The maximum number of posts to render in the feed.
 
@@ -1025,6 +1029,7 @@ prefix and post prefix.  @xref{Blog} for more information.
 
 @deffn {Procedure} atom-feeds-by-tag [#:prefix "feeds/tags"] @
                                      [#:filter posts/reverse-chronological] @
+                                     [#:last-updated (current-date)] @
                                      [#:max-entries 20] [#:blog-prefix ""]
 Return a builder procedure that renders an atom feed for every tag
 used in a post.  All arguments are optional:
@@ -1037,6 +1042,9 @@ The directory in which to write the feeds.
 @item filter
 The procedure called to manipulate the posts list before rendering.
 
+@item last-updated
+The feed last updated date.  Defaults to the current date.
+
 @item max-entries
 The maximum number of posts to render in each feed.
 
@@ -1057,6 +1065,7 @@ prefix and post prefix.  @xref{Blog} for more information.
 
 @deffn {Procedure} rss-feed [#:file-name "rss-feed.xml"] [#:subtitle "Recent Posts"] @
                             [#:filter posts/reverse-chronological] @
+                            [#:publication-date (current-date)] @
                             [#:max-entries 20] [#:blog-prefix ""]
 Return a builder procedure that renders a list of posts as an RSS
 feed.  All arguments are optional:
@@ -1072,6 +1081,9 @@ The feed subtitle.
 @item filter
 The procedure called to manipulate the posts list before rendering.
 
+@item publication-date
+The feed publication date.  Defaults to the current date.
+
 @item max-entries
 The maximum number of posts to render in the feed.
 
diff --git a/haunt/builder/atom.scm b/haunt/builder/atom.scm
index 9a015b2..c580aaf 100644
--- a/haunt/builder/atom.scm
+++ b/haunt/builder/atom.scm
@@ -171,6 +171,7 @@
                     (file-name "feed.xml")
                     (subtitle "Recent Posts")
                     (filter posts/reverse-chronological)
+                    (last-updated (current-date))
                     (max-entries 20)
                     (blog-prefix ""))
   "Return a builder procedure that renders a list of posts as an Atom
@@ -182,6 +183,8 @@ SUBTITLE: The feed subtitle.
 
 FILTER: The procedure called to manipulate the posts list before rendering.
 
+LAST-UPDATED: The feed last updated date.
+
 MAX-ENTRIES: The maximum number of posts to render in the feed.
 
 BLOG-PREFIX: The prefix for all post URLs, which is the combination of
@@ -196,7 +199,7 @@ the blog's prefix and post prefix."
                                   (title ,(site-title site))
                                   (id ,uri)
                                   (subtitle ,subtitle)
-                                  (updated ,(date->string* (current-date)))
+                                  (updated ,(date->string* last-updated))
                                   (link (@ (href ,uri) (rel "self")))
                                   (link (@ (href
                                             ,(uri->string
@@ -211,6 +214,7 @@ the blog's prefix and post prefix."
 (define* (atom-feeds-by-tag #:key
                             (prefix "feeds/tags")
                             (filter posts/reverse-chronological)
+                            (last-updated (current-date))
                             (max-entries 20)
                             (blog-prefix ""))
   "Return a builder procedure that renders an atom feed for every tag
@@ -221,6 +225,8 @@ PREFIX: The directory in which to write the feeds.
 FILTER: The procedure called to manipulate the posts list before
 rendering.
 
+LAST-UPDATED: The feed last updated date.
+
 MAX-ENTRIES: The maximum number of posts to render in each feed.
 
 BLOG-PREFIX: The prefix for all post URLs, which is the combination of
@@ -232,6 +238,7 @@ the blog's prefix and post prefix."
              ((atom-feed #:file-name (string-append prefix "/" tag ".xml")
                          #:subtitle (string-append "Tag: " tag)
                          #:filter filter
+                         #:last-updated last-updated
                          #:max-entries max-entries
                          #:blog-prefix blog-prefix)
               site posts)))
diff --git a/haunt/builder/rss.scm b/haunt/builder/rss.scm
index d614d9d..d78a26b 100644
--- a/haunt/builder/rss.scm
+++ b/haunt/builder/rss.scm
@@ -92,6 +92,7 @@
                    (subtitle "Recent Posts")
                    (filter posts/reverse-chronological)
                    (max-entries 20)
+                   (publication-date (current-date))
                    (blog-prefix ""))
   "Return a builder procedure that renders a list of posts as an RSS
 feed.  All arguments are optional:
@@ -105,6 +106,8 @@ rendering.
 
 MAX-ENTRIES: The maximum number of posts to render in the feed.
 
+PUBLICATION-DATE: The feed publication date.
+
 BLOG-PREFIX: The prefix for all post URLs, which is the combination of
 the blog's prefix and post prefix."
   (lambda (site posts)
@@ -116,7 +119,7 @@ the blog's prefix and post prefix."
                                 ;; It looks like RSS's description and atom's subtitle
                                 ;; are equivalent?
                                 (description ,subtitle)
-                                (pubDate ,(date->rfc822-str (current-date)))
+                                (pubDate ,(date->rfc822-str publication-date))
                                 (link
                                  ,(string-append (symbol->string
                                                   (site-scheme site))