depot/third_party/tvl/web/bubblegum/examples/blog.nix
Default email a291c8690a Project import generated by Copybara.
GitOrigin-RevId: e6e19f3d81a982a62e1bba08f0b4f7fdc21b4ea0
2022-05-19 16:39:52 +02:00

143 lines
2.9 KiB
Nix

{ depot, ... }:
let
inherit (depot.third_party.nixpkgs)
lib
;
inherit (depot.users.sterni.nix)
url
fun
string
;
inherit (depot.web.bubblegum)
pathInfo
scriptName
respond
absolutePath
;
# substituted using substituteAll in default.nix
blogdir = "@blogdir@";
# blogdir = toString ./posts; # for local testing
parseDate = post:
let
matched = builtins.match "/?([0-9]+)-([0-9]+)-([0-9]+)-.+" post;
in
if matched == null
then [ 0 0 0 ]
else builtins.map builtins.fromJSON matched;
parseTitle = post:
let
matched = builtins.match "/?[0-9]+-[0-9]+-[0-9]+-(.+).html" post;
in
if matched == null
then "no title"
else builtins.head matched;
dateAtLeast = a: b:
builtins.all fun.id
(lib.zipListsWith (partA: partB: partA >= partB) a b);
byPostDate = a: b:
dateAtLeast (parseDate a) (parseDate b);
posts = builtins.sort byPostDate
(builtins.attrNames
(lib.filterAttrs (_: v: v == "regular")
(builtins.readDir blogdir)));
generic = { title, inner, ... }: ''
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>${title}</title>
<style>a:link, a:visited { color: blue; }</style>
</head>
<body>
${inner}
</body>
</html>
'';
index = posts: ''
<main>
<h1>blog posts</h1>
<ul>
'' + lib.concatMapStrings
(post: ''
<li>
<a href="${absolutePath (url.encode {} post)}">${parseTitle post}</a>
</li>
'')
posts + ''
</ul>
</main>
'';
formatDate =
let
# Assume we never deal with years < 1000
formatDigit = d: string.fit
{
char = "0";
width = 2;
}
(toString d);
in
lib.concatMapStringsSep "-" formatDigit;
post = title: post: ''
<main>
<h1>${title}</h1>
<div id="content">
${builtins.readFile (blogdir + "/" + post)}
</div>
</main>
<footer>
<p>Posted on ${formatDate (parseDate post)}</p>
<nav><a href="${scriptName}">index</a></nav>
</footer>
'';
validatePathInfo = pathInfo:
let
chars = string.toChars pathInfo;
in
builtins.length chars > 1
&& !(builtins.elem "/" (builtins.tail chars));
response =
if pathInfo == "/"
then {
title = "blog";
status = 200;
inner = index posts;
}
else if !(validatePathInfo pathInfo)
then {
title = "Bad Request";
status = 400;
inner = "No slashes in post names 😡";
}
# CGI should already url.decode for us
else if builtins.pathExists (blogdir + "/" + pathInfo)
then rec {
title = parseTitle pathInfo;
status = 200;
inner = post title pathInfo;
} else {
title = "Not Found";
status = 404;
inner = "<h1>404 not found</h1>";
};
in
respond response.status
{
"Content-type" = "text/html";
}
(generic response)