generate an rss feed

README

@@ -25,6 +25,7 @@ Perl modules (and which Debian packages they come from):
 • File::Slurper (‹libfile-slurper-perl›)
 • Date::Parse (‹libtimedate-perl›)
 • File::Find::Rule (‹libfile-find-rule-perl›)
+• Guard (‹libguard-perl›)
 
 ## Articles
 

gib/main

@@ -204,6 +204,14 @@ dep $(a)/archive.gib
 use byproduct
 add deployed-files $(out)
 
+# RSS
+for a .
+out $(a)/articles.rss
+dep $(a)/index
+dep $(archives.$a)/perex.html
+dep templates/rss.tt
+cmd $(tool) mkrss
+add deployed-files $(out)
 
 # other resources
 set copied-resources robots.txt favicon16.png

resources/style.css

@@ -91,6 +91,7 @@ html {
     --f-serif:  'DejaVu Serif', 'Bitstream Vera Serif', 'Georgia';
     --f-sans:   'DejaVu Sans', 'Bitstream Vera Sans', 'Verdana';
     --f-mono:   'DejaVu Sans Mono', 'Bitstream Vera Sans Mono';
+    --i-rss:    url('data:image/svg+xml;utf8,<svg width="32" height="32" version="1.1" viewBox="0 0 8.4667 8.4667" xmlns="http://www.w3.org/2000/svg" fill="currentColor"><g transform="translate(0 -161.53)"><path transform="matrix(.26458 0 0 .26458 0 161.53)" d="m3 2v5h3a19 19 0 0 1 19 19v3h5v-3a24 24 0 0 0-24-24h-3zm0 10v5h3a8.9999 8.9999 0 0 1 9 9v3h5v-3a14 14 0 0 0-14-14h-3zm3 10a4 4 0 0 0-4 4 4 4 0 0 0 4 4 4 4 0 0 0 4-4 4 4 0 0 0-4-4z"/></g></svg>');
 }
 
 /* General - fonts and light theme colours */
@@ -706,6 +707,30 @@ figure.float {
     margin: auto 0;
 }
 
+a[rel~="alternate"][type="application/rss+xml"] {
+    font-size: 60%;
+}
+@supports (mask-image: url()) or (-webkit-mask-image: url()) {
+    a[rel~="alternate"][type="application/rss+xml"] {
+        font-size: 0;
+        visibility: hidden;
+    }
+    a[rel~="alternate"][type="application/rss+xml"]::after {
+        content: "";
+        display: inline-block;
+        visibility: visible;
+        width: 1rem;
+        height: 1rem;
+        background-color: currentColor;
+        -webkit-mask-image: var(--i-rss);
+        -webkit-mask-size: contain;
+        -webkit-mask-repeat: no-repeat;
+        mask-image: var(--i-rss);
+        mask-size: contain;
+        mask-repeat: no-repeat;
+    }
+}
+
 /* Small (but not tiny) size */
 @media screen and (min-width: 36em) {
     #sidebar > header h1 {

templates/nav.tt

@@ -26,7 +26,8 @@
     </menu>
 </nav>
 <nav id=latest-articles class=extended>
-    <header>Poslední</header>
+    <header>Nové články <a href='[% root %]/articles.rss' rel=alternate
+type='application/rss+xml'>[RSS]</a></header>
     <menu>
         [%- FOREACH a IN latest %]
         <li><div><a href="[% root %]/[% a.id %]"><header>[% a.title %]</header>

templates/rss.tt

+<?xml version="1.0" encoding="UTF-8"?>
+<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
+<channel>
+<title>Adamatův blogísek</title>
+<link>[% root_absolute %]/</link>
+<description>Články z Adamatova blogísku</description>
+<language>cs</language>
+<generator>Adamatův blogískový orloj</generator>
+<ttl>1440</ttl>
+<atom:link href="[% root_absolute %]/articles.rss" rel="self" type="application/rss+xml" />
+[%- FOR i IN items %]
+<item>
+<title>[% i.title_plain | xml %]</title>
+<link>[% root_absolute %]/[% i.id %]/</link>
+<guid>[% root_absolute %]/[% i.id %]</guid>
+<pubDate>[% rfc822stamp( i.published ) %]</pubDate>
+[%- IF i.category %]
+<category>[% i.category %]</category>
+[%- END %]
+<description>[% INSERT "$i.id/perex.html" | utf8 | rsshacks | xml %]</description>
+</item>
+[%- END %]
+</channel>
+</rss>

tools/Blogisek.pm

@@ -16,6 +16,8 @@ use Time::Piece;
 use Date::Parse;
 use File::Slurper qw/read_lines/;
 use Encode qw/decode_utf8/;
+use Guard;
+use POSIX qw/locale_h/;
 
 # Report use of this module to gib
 open my $gibfh, '+<&3';
@@ -27,9 +29,11 @@ our ($srcdir, $outdir) = @ENV{qw/SRCDIR OUTDIR/};
 $srcdir //= '.';
 $outdir //= '.';
 
-our @indexfields = qw/id title category ncomments stamp banner banner_alt/;
+our @indexfields = qw/id title category ncomments stamp banner banner_alt title_plain/;
 
 our $root = $ENV{DOCUMENT_ROOT} // '';
+my $root_absolute = 'https://blogisek.adamat.dev';
+
 my $now = localtime;
 our $template = Template->new({
         ENCODING     => 'utf8',
@@ -40,16 +44,19 @@ our $template = Template->new({
         RECURSION    => 1,              # for comment replies
         FILTERS      => {
             utf8 => sub { decode_utf8( $_[0] ); },
+            rsshacks => \&rss_filter,
         },
         PRE_PROCESS  => 'defs',
         # COMPILE_DIR  => '_tt',
         # COMPILE_EXT  => '.pl',
         VARIABLES    => {
             root => $root,
+            root_absolute => $root_absolute,
             now => $now,
             datef => sub { $_[0]->ymd },
             timef => sub { $_[0]->strftime( '%H.%M' ) },
             isostamp => sub { $_[0]->strftime( '%FT%T%z' ) },
+            rfc822stamp => \&rfc822stamp,
             plur => \&plural,
             qotd => \&qotd,
             genimgattr => \&genimgattr,
@@ -106,6 +113,7 @@ sub load_meta($src) {
     }
     $h->{banner} //= '';
     $h->{banner_alt} //= '';
+    $h->{title_plain} //= $h->{title};
     return {
         %$h,
     };
@@ -191,4 +199,16 @@ sub genimgattr($src, $mini=0) {
     return $attrs;
 }
 
+sub rfc822stamp($t) {
+    my $original = setlocale( LC_TIME );
+    my $guard = scope_guard { setlocale( LC_TIME, $original ) };
+    setlocale( LC_TIME, 'C' );
+    return $t->strftime( '%a, %d %b %Y %T %z' );
+}
+
+sub rss_filter($s) {
+    $s =~ s,(\b(href)\s*=\s*['"]?)/,$1$root_absolute/,gi;
+    return $s;
+}
+
 1;

tools/mkrss

+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use utf8;
+use open qw/:std :encoding(utf-8)/;
+
+use lib './tools';
+use Blogisek;
+
+my @index = load_index( '.' )
+    or die 'Failed to load index';
+
+splice @index, 20;
+
+$template->process( 'rss.tt', { items => \@index }, "articles.rss" )
+    or die $template->error;
+