tvl-depot/users/tazjin/blog/fragments.nix
Vincent Ambo 916dba43e7 feat(tazjin/atom-feed): Add Nix functions for generating an Atom feed
This only adds the feed generation functions, but does not yet wire it
up to the blog content.

This was implemented against
https://validator.w3.org/feed/docs/atom.html and I've validated some
generated example feeds with the W3 validator.

Change-Id: Ide3ea90d3fa935047506aa87169100c2ead21284
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1709
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
2020-08-10 23:24:44 +00:00

97 lines
3.1 KiB
Nix

# This file defines various fragments of the blog, such as the header
# and footer, as functions that receive arguments to be templated into
# them.
#
# An entire post is rendered by `renderPost`, which assembles the
# fragments together in a runCommand execution.
#
# The post index is generated by //users/tazjin/homepage, not by this
# code.
{ depot, lib, ... }:
let
inherit (builtins) filter map hasAttr replaceStrings toFile;
inherit (depot.third_party) runCommandNoCC writeText;
# Generate a post list for all listed, non-draft posts.
isDraft = post: (hasAttr "draft" post) && post.draft;
isUnlisted = post: (hasAttr "listed" post) && !post.listed;
escape = replaceStrings [ "<" ">" "&" "'" ] [ "&lt;" "&gt;" "&amp;" "&#39;" ];
header = title: ''
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="tazjin&#39;s blog">
<link rel="stylesheet" type="text/css" href="/static/tazjin.css" media="all">
<link rel="icon" type="image/webp" href="/static/favicon.webp">
<link rel="alternate" type="application/rss+xml" title="RSS-Feed" href="/rss.xml">
<title>tazjin&#39;s blog: ${escape title}</title>
</head>
<body class="light">
<header>
<h1><a class="blog-title" href="/">tazjin&#39;s interblag</a> </h1>
<hr>
</header>
'';
footer = ''
<hr>
<footer>
<p class="footer">
<a class="uncoloured-link" href="https://tazj.in">homepage</a>
|
<a class="uncoloured-link" href="https://git.tazj.in/about">code</a>
|
<a class="uncoloured-link" href="https://twitter.com/tazjin">twitter</a>
</p>
<p class="lod">_</p>
</footer>
</body>
'';
draftWarning = toFile "draft.html" ''
<p class="cheddar-callout cheddar-warning">
<b>Note:</b> This post is a <b>draft</b>! Please do not share
the link to it without asking me first.
</p>
<hr>
'';
unlistedWarning = toFile "unlisted.html" ''
<p class="cheddar-callout cheddar-warning">
<b>Note:</b> This post is <b>unlisted</b>! Please do not share
the link to it without asking me first.
</p>
<hr>
'';
renderPost = post: runCommandNoCC "${post.key}.html" {} ''
cat ${toFile "header.html" (header post.title)} > $out
# Write the post title & date
echo '<article><h2 class="inline">${escape post.title}</h2>' >> $out
echo '<aside class="date">' >> $out
date --date="@${toString post.date}" '+%Y-%m-%d' >> $out
echo '</aside>' >> $out
${
# Add a warning to draft/unlisted posts to make it clear that
# people should not share the post.
if (isDraft post) then "cat ${draftWarning} >> $out"
else if (isUnlisted post) then "cat ${unlistedWarning} >> $out"
else "# Your ads could be here?"
}
# Write the actual post through cheddar's about-filter mechanism
cat ${post.content} | ${depot.tools.cheddar}/bin/cheddar --about-filter ${post.content} >> $out
echo '</article>' >> $out
cat ${toFile "footer.html" footer} >> $out
'';
in {
inherit renderPost isDraft isUnlisted;
}