tvl-depot/web/blog/fragments.nix

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# 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.
{ depot, lib, pkgs, ... }:
let
inherit (builtins) filter map hasAttr replaceStrings;
inherit (pkgs) runCommand writeText;
inherit (depot.nix) renderMarkdown;
# 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 = name: title: staticUrl: ''
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="${escape name}">
<link rel="stylesheet" type="text/css" href="${staticUrl}/tvl.css" media="all">
<link rel="icon" type="image/webp" href="/static/favicon.webp">
<link rel="alternate" type="application/atom+xml" title="Atom Feed" href="https://tvl.fyi/feed.atom">
<title>${escape name}: ${escape title}</title>
</head>
<body class="light">
<header>
<h1><a class="blog-title" href="/">${escape name}</a> </h1>
<hr>
</header>
'';
fullFooter = content: ''
<hr>
<footer>
${content}
</footer>
</body>
'';
draftWarning = writeText "draft.html" ''
<p class="cheddar-callout cheddar-warning">
<b>Note:</b> This post is a <b>draft</b>! Please do not share
the link to it without asking first.
</p>
<hr>
'';
unlistedWarning = writeText "unlisted.html" ''
<p class="cheddar-callout cheddar-warning">
<b>Note:</b> This post is <b>unlisted</b>! Please do not share
the link to it without asking first.
</p>
<hr>
'';
renderPost = { name, footer, staticUrl ? "https://static.tvl.fyi/${depot.web.static.drvHash}", ... }: post: runCommand "${post.key}.html" { } ''
cat ${writeText "header.html" (header name post.title staticUrl)} > $out
# Write the post title & date
echo '<article><h2 class="inline">${escape post.title}</h2>' >> $out
echo '<aside class="date">' >> $out
date --date="@${toString post.date}" '+%Y-%m-%d' >> $out
${
if post ? updated
then ''date --date="@${toString post.updated}" '+ (updated %Y-%m-%d)' >> $out''
else ""
}
${if post ? author then "echo ' by ${post.author}' >> $out" else ""}
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 ${renderMarkdown { path = post.content; tagfilter = post.tagfilter or true; }} >> $out
echo '</article>' >> $out
cat ${writeText "footer.html" (fullFooter footer)} >> $out
'';
in
{
inherit isDraft isUnlisted renderPost;
}