add support for generating per-page rss feeds

7 files changed, 120 insertions, 6 deletions

diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index df24fd568..646e254a5 100644
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -79,7 +79,13 @@ sub parentlinks ($) { #{{{
 	return @ret;
 } #}}}
 
-sub finalize ($$$) { #{{{
+sub rsspage ($) { #{{{
+	my $page=shift;
+
+	return $page.".rss";
+} #}}}
+
+sub genpage ($$$) { #{{{
 	my $content=shift;
 	my $page=shift;
 	my $mtime=shift;
@@ -102,6 +108,10 @@ sub finalize ($$$) { #{{{
 		$u=~s/\[\[file\]\]/$pagesources{$page}/g;
 		$template->param(historyurl => $u);
 	}
+
+	if ($config{rss}) {
+		$template->param(rssurl => rsspage($page));
+	}
 	
 	$template->param(
 		title => $title,
@@ -116,6 +126,59 @@ sub finalize ($$$) { #{{{
 	return $template->output;
 } #}}}
 
+sub date_822 ($) { #{{{
+	my $time=shift;
+
+	eval q{use POSIX};
+	return POSIX::strftime("%a, %d %b %Y %H:%M:%S %z", localtime($time));
+} #}}}
+
+sub absolute_urls ($$) { #{{{
+	my $content=shift;
+	my $url=shift;
+
+	$url=~s/[^\/]+$//;
+	
+	$content=~s{<a\s+href="([^"]+)"}{
+		"<a href=\"$url$1\""
+	}ieg;
+	$content=~s{<img\s+src="([^"]+)"}{
+		"<img src=\"$url$1\""
+	}ieg;
+	return $content;
+} #}}}
+
+sub genrss ($$$) { #{{{
+	my $content=shift;
+	my $page=shift;
+	my $mtime=shift;
+
+	my $url="$config{url}/".htmlpage($page);
+	
+	my $template=HTML::Template->new(blind_cache => 1,
+		filename => "$config{templatedir}/rsspage.tmpl");
+	
+	# Regular page gets a feed that is updated every time the
+	# page is changed, so the mtime is encoded in the guid.
+	my @items=(
+		{
+			itemtitle => pagetitle(basename($page)),
+			itemguid => "$url?mtime=$mtime",
+			itemurl => $url,
+			itempubdate => date_822($mtime),
+			itemcontent => absolute_urls($content, $url), # rss sucks
+		},
+	);
+	
+	$template->param(
+		title => pagetitle(basename($page)),
+		pageurl => $url,
+		items => \@items,
+	);
+	
+	return $template->output;
+} #}}}
+
 sub check_overwrite ($$) { #{{{
 	# Important security check. Make sure to call this before saving
 	# any files to the source directory.
@@ -161,13 +224,20 @@ sub render ($) { #{{{
 		
 		$content=linkify($content, $page);
 		$content=htmlize($type, $content);
-		$content=finalize($content, $page,
-			mtime("$config{srcdir}/$file"));
 		
 		check_overwrite("$config{destdir}/".htmlpage($page), $page);
-		writefile("$config{destdir}/".htmlpage($page), $content);
+		writefile("$config{destdir}/".htmlpage($page),
+			genpage($content, $page, mtime("$config{srcdir}/$file")));		
 		$oldpagemtime{$page}=time;
 		$renderedfiles{$page}=htmlpage($page);
+
+		# TODO: should really add this to renderedfiles and call
+		# check_overwrite, as above, but currently renderedfiles
+		# only supports listing one file per page.
+		if ($config{rss}) {
+			writefile("$config{destdir}/".rsspage($page),
+				genrss($content, $page, mtime("$config{srcdir}/$file")));
+		}
 	}
 	else {
 		$links{$file}=[];
diff --git a/doc/features.mdwn b/doc/features.mdwn
index c20da504d..4699f3096 100644
--- a/doc/features.mdwn
+++ b/doc/features.mdwn
@@ -27,6 +27,13 @@ Currently implemented:
   and is quite smart about converting it to html. The only additional markup
   provided by ikiwiki aside from regular markdown is the [[WikiLink]].
 
+* [[RSS]]
+
+  ikiwiki supports generating RSS (2.0) feed for individual pages. These
+  feeds can be subscribed to, to get an update when a page is changed.
+
+  (Support for proper blogs is also planned.)
+
 * support for other file types
 
   ikiwiki also supports files of any other type, including raw html, text,
diff --git a/doc/ikiwiki.setup b/doc/ikiwiki.setup
index 374093a5e..b81983080 100644
--- a/doc/ikiwiki.setup
+++ b/doc/ikiwiki.setup
@@ -44,4 +44,6 @@ use IkiWiki::Setup::Standard {
 	
 	# Can anonymous web users edit pages?
 	#anonok => 1,
+	# Generate rss feeds for pages?
+	#rss => 1,
 }
diff --git a/doc/usage.mdwn b/doc/usage.mdwn
index b9744438b..02d01f49c 100644
--- a/doc/usage.mdwn
+++ b/doc/usage.mdwn
@@ -64,6 +64,12 @@ flags such as --verbose can be negated with --no-verbose.
 
   By default, anonymous users cannot edit the wiki.
 
+* --rss, --norss
+
+  If rss is set, along with every html page rendered by ikiwiki, an rss
+  page will also be rendered, to allow users to subscribe to a rss feed of
+  changes to that page.
+
 * --cgi
 
   Enable [[CGI]] mode. In cgi mode ikiwiki runs as a cgi script, and supports editing pages, signing in, registration, and displaying [[RecentChanges]].
diff --git a/ikiwiki b/ikiwiki
index 3540f8667..5c708919a 100755
--- a/ikiwiki
+++ b/ikiwiki
@@ -30,6 +30,7 @@ sub getconfig () { #{{{
 			historyurl => '',
 			diffurl => '',
 			anonok => 0,
+			rss => 0,
 			rebuild => 0,
 			wrapper => undef,
 			wrappermode => undef,
@@ -49,6 +50,7 @@ sub getconfig () { #{{{
 			"wrappermode=i" => \$config{wrappermode},
 			"svn!" => \$config{svn},
 			"anonok!" => \$config{anonok},
+			"rss!" => \$config{rss},
 			"cgi!" => \$config{cgi},
 			"url=s" => \$config{url},
 			"cgiurl=s" => \$config{cgiurl},
@@ -85,7 +87,10 @@ sub getconfig () { #{{{
 
 sub checkconfig () { #{{{
 	if ($config{cgi} && ! length $config{url}) {
-		error("Must specify url to wiki with --url when using --cgi");
+		error("Must specify url to wiki with --url when using --cgi\n");
+	}
+	if ($config{rss} && ! length $config{url}) {
+		error("Must specify url to wiki with --url when using --rss\n");
 	}
 	
 	$config{wikistatedir}="$config{srcdir}/.ikiwiki"
diff --git a/templates/page.tmpl b/templates/page.tmpl
index 1e484056e..5a7450af7 100644
--- a/templates/page.tmpl
+++ b/templates/page.tmpl
@@ -41,7 +41,10 @@
 
 <p>
 <!-- from <TMPL_VAR NAME=WIKINAME> -->
-last edited <TMPL_VAR NAME=MTIME>
+Last edited <TMPL_VAR NAME=MTIME>
+<TMPL_IF NAME="RSSURL">
+; <a type="application/rss+xml" href="<TMPL_VAR NAME=RSSURL>">RSS</a>
+</TMPL_IF>
 </p>
 
 </body>
diff --git a/templates/rsspage.tmpl b/templates/rsspage.tmpl
new file mode 100644
index 000000000..cbfeb5471
--- /dev/null
+++ b/templates/rsspage.tmpl
@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<rss version="2.0">
+	<channel>
+		<title><TMPL_VAR TITLE ESCAPE=HTML></title>
+		<link><TMPL_VAR PAGEURL></link>
+		<description><TMPL_VAR TITLE ESCAPE=HTML></description>
+		<TMPL_LOOP NAME="ITEMS">
+		<item>
+			<title><TMPL_VAR ITEMTITLE ESCAPE=HTML></title>
+			<TMPL_IF NAME="ITEMGUID">
+			<guid isPermaLink="false"><TMPL_VAR ITEMGUID></guid>
+			<TMPL_ELSE>
+			<guid><TMPL_VAR ITEMURL></guid>
+			</TMPL_IF>
+			<link><TMPL_VAR ITEMURL></link>
+			<pubDate><TMPL_VAR ITEMPUBDATE></pubDate>
+			<description><![CDATA[<TMPL_VAR ITEMCONTENT>]]></description>
+		</item>
+		</TMPL_LOOP>
+	</channel>
+</rss>