fuzzyworld-tools / files / server / site-blog / blog.js
blog.js
0e603cf7 2026-10-31 Pavel Safronov | 1 | /* The blog's two small conveniences: a light/dark switch and a reading-progress bar. No dependencies. |
| 2 | The choice is kept in localStorage; with none, the system setting decides (see _shared.css). | |
| 3 | Loaded in <head> so the saved theme is applied before the first paint. */ | |
| 4 | (function () { | |
| 5 | var root = document.documentElement, KEY = "fw-theme", saved = null; | |
| 6 | try { saved = localStorage.getItem(KEY); } catch (e) {} | |
| 7 | if (saved === "light" || saved === "dark") root.setAttribute("data-theme", saved); | |
| 8 | ||
| 9 | function effective() { | |
| 10 | var t = root.getAttribute("data-theme"); | |
| 11 | return t || (window.matchMedia && matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light"); | |
| 12 | } | |
| 13 | ||
| 14 | document.addEventListener("DOMContentLoaded", function () { | |
| 15 | var bar = document.querySelector("header.site .bar"); | |
| 16 | if (bar) { | |
| 17 | var b = document.createElement("button"); | |
| 18 | b.type = "button"; | |
| 19 | b.className = "theme-toggle"; | |
| 20 | var label = function () { | |
| 21 | var dark = effective() === "dark"; | |
| 22 | b.textContent = dark ? "☀" : "☾"; | |
| 23 | var text = dark ? "Switch to the light theme" : "Switch to the dark theme"; | |
| 24 | b.title = text; | |
| 25 | b.setAttribute("aria-label", text); | |
| 26 | }; | |
| 27 | b.addEventListener("click", function () { | |
| 28 | var next = effective() === "dark" ? "light" : "dark"; | |
| 29 | root.setAttribute("data-theme", next); | |
| 30 | try { localStorage.setItem(KEY, next); } catch (e) {} | |
| 31 | label(); | |
| 32 | }); | |
| 33 | label(); | |
| 34 | bar.appendChild(b); | |
| 35 | if (window.matchMedia) { // the system setting changed: the label follows unless the reader chose a theme | |
| 36 | var mq = matchMedia("(prefers-color-scheme: dark)"); | |
| 37 | if (mq.addEventListener) mq.addEventListener("change", label); else if (mq.addListener) mq.addListener(label); | |
| 38 | } | |
| 39 | } | |
| 40 | ||
| 41 | var post = document.querySelector(".post-body"); | |
| 42 | if (post) { | |
| 43 | var p = document.createElement("div"); | |
| 44 | p.className = "progress"; | |
| 45 | p.setAttribute("aria-hidden", "true"); | |
| 46 | document.body.appendChild(p); | |
| 47 | var update = function () { // 0 at the top of the page, 1 at the bottom | |
| 48 | var room = document.documentElement.scrollHeight - window.innerHeight; | |
| 49 | var done = room > 0 ? window.scrollY / room : 0; | |
| 50 | p.style.width = Math.max(0, Math.min(1, done)) * 100 + "%"; | |
| 51 | }; | |
| 52 | window.addEventListener("scroll", update, { passive: true }); | |
| 53 | window.addEventListener("resize", update); | |
| 54 | update(); | |
| 55 | } | |
e9fdc5db 2026-11-01 Pavel Safronov | 56 | |
| 57 | comments(); | |
0e603cf7 2026-10-31 Pavel Safronov | 58 | }); |
e9fdc5db 2026-11-01 Pavel Safronov | 59 | |
| 60 | /* Reader comments: /_comments/<post>.json is written by the server. Missing (404), broken or not a list: nothing shown. | |
| 61 | Items are built with createElement/textContent only. Comments already in the page (imported, id="comment-N") are skipped. */ | |
| 62 | function comments() { | |
| 63 | var started = Date.now(); | |
| 64 | var sections = document.querySelectorAll(".comments-section[data-src]"); | |
| 65 | Array.prototype.forEach.call(sections, function (sec) { | |
| 66 | var form = sec.querySelector("form.comment-form"); | |
| 67 | if (form) form.addEventListener("submit", function () { | |
| 68 | var f = form.elements.elapsed; | |
| 69 | if (f) f.value = String(Date.now() - started); | |
| 70 | }); | |
| 71 | if (!window.fetch) return; | |
| 72 | fetch(sec.getAttribute("data-src"), { credentials: "omit", headers: { Accept: "application/json" } }) | |
| 73 | .then(function (r) { return r.ok ? r.json() : null; }) | |
| 74 | .then(function (list) { if (Array.isArray(list)) show(sec, list); }) | |
| 75 | .catch(function () {}); | |
| 76 | }); | |
| 77 | } | |
| 78 | ||
| 79 | function cid(c) { return c && c.id != null ? String(c.id).replace(/[^A-Za-z0-9_-]/g, "") : ""; } | |
| 80 | ||
| 81 | function show(sec, list) { | |
| 82 | var box = sec.querySelector(".comments-live") || sec; | |
| 83 | var fresh = list.filter(function (c) { | |
| 84 | return c && typeof c === "object" && cid(c) && !document.getElementById("comment-" + cid(c)); | |
| 85 | }); | |
| 86 | fresh.sort(function (a, b) { return String(a.date || "") < String(b.date || "") ? -1 : String(a.date || "") > String(b.date || "") ? 1 : 0; }); | |
| 87 | var made = Object.create(null); | |
| 88 | fresh.forEach(function (c) { made[cid(c)] = item(c); }); | |
| 89 | var top = document.createElement("ul"); | |
| 90 | top.className = "comments"; | |
| 91 | fresh.forEach(function (c) { | |
| 92 | var li = made[cid(c)], pid = c.parent ? cid({ id: c.parent }) : ""; | |
| 93 | var parent = pid && pid !== cid(c) ? (made[pid] || document.getElementById("comment-" + pid)) : null; | |
| 94 | if (!parent) { top.appendChild(li); return; } | |
| 95 | var ul = null; | |
| 96 | for (var n = parent.firstChild; n; n = n.nextSibling) if (n.nodeName === "UL") ul = n; | |
| 97 | if (!ul) { ul = document.createElement("ul"); ul.className = "comments"; parent.appendChild(ul); } | |
| 98 | ul.appendChild(li); | |
| 99 | }); | |
| 100 | if (top.firstChild) box.appendChild(top); | |
| 101 | } | |
| 102 | ||
| 103 | function item(c) { | |
| 104 | var li = document.createElement("li"); | |
| 105 | li.className = "comment"; | |
| 106 | li.id = "comment-" + cid(c); | |
| 107 | var meta = document.createElement("p"); | |
| 108 | meta.className = "meta"; | |
| 109 | var who = document.createElement("strong"); | |
| 110 | who.textContent = String(c.author == null ? "" : c.author); | |
| 111 | meta.appendChild(who); | |
| 112 | meta.appendChild(document.createTextNode(" · " + String(c.date == null ? "" : c.date).slice(0, 10))); | |
| 113 | var body = document.createElement("p"); | |
| 114 | String(c.text == null ? "" : c.text).replace(/\r\n/g, "\n").split("\n").forEach(function (line, i) { | |
| 115 | if (i) { body.appendChild(document.createElement("br")); body.appendChild(document.createTextNode("\n")); } | |
| 116 | body.appendChild(document.createTextNode(line)); | |
| 117 | }); | |
| 118 | li.appendChild(meta); | |
| 119 | li.appendChild(body); | |
| 120 | return li; | |
| 121 | } | |
0e603cf7 2026-10-31 Pavel Safronov | 122 | })(); |