MeFi Navigator Redux

MetaFilter: navigate through users' comments, and highlight comments by OP and yourself

Verze ze dne 02. 05. 2025. Zobrazit nejnovější verzi.

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         MeFi Navigator Redux
// @namespace    https://github.com/klipspringr/mefi-userscripts
// @version      2025-05-02
// @description  MetaFilter: navigate through users' comments, and highlight comments by OP and yourself
// @author       Klipspringer
// @supportURL   https://github.com/klipspringr/mefi-userscripts
// @license      MIT
// @match        *://*.metafilter.com/*
// @grant        none
// ==/UserScript==

const SVG_UP = `<svg xmlns="http://www.w3.org/2000/svg" hidden style="display:none"><path id="mfnr-up" fill="currentColor" d="M 0 93.339 L 50 6.661 L 100 93.339 L 50 64.399 L 0 93.339 Z" /></svg>`;
const SVG_DOWN = `<svg xmlns="http://www.w3.org/2000/svg" hidden style="display:none"><path id="mfnr-down" fill="currentColor" d="M 100 6.69 L 50 93.31 L 0 6.69 L 50 35.607 L 100 6.69 Z" /></svg>`;

// CSS notes:
// - mfnr-op needs to play nicely with .mod in threads where OP is a mod
// - classic theme has different margins from modern, so we can't change margin-left without knowing what theme we're on
// - relative positioning seems to work better
const CLASSES = `<style>
.mfnr-op {
    border-left: 5px solid #0004 !important;
    padding-left: 10px !important;
    position: relative !important;
    left: -15px !important;
}
@media (max-width: 550px) {
    .mfnr-op {
        left: -5px !important;
    }
}
.mfnr-self-badge {
    background-color: #C8E0A1;
    border-radius: 2px;
    color: #000;
    font-size: 0.8em;
    margin-left: 4px;
    padding: 0 4px;
    cursor: default;
}
.mfnr-nav {
    white-space: nowrap;
}
.mfnr-nav svg {
    vertical-align: middle;
    top: -1px;
}
</style>`;

const ATTR_BYLINE = "data-mfnr-byline";

const getCookie = (key) => {
    const s = RegExp(key + "=([^;]+)").exec(document.cookie);
    if (!s || !s[1]) return null;
    return decodeURIComponent(s[1]);
};

const markSelf = (targetNode) => {
    const span = document.createElement("span");
    span.classList.add("mfnr-self-badge");
    span.textContent = "me";
    targetNode.after(span);
};

const markOP = (targetNode) =>
    targetNode.parentElement.parentElement.classList.add("mfnr-op");

const createLink = (href, svgHref) => {
    const a = document.createElement("a");
    a.setAttribute("href", "#" + href);
    const svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
    svg.setAttribute("width", "1em");
    svg.setAttribute("viewBox", "0 0 100 100");
    svg.setAttribute("class", "mfnr-nav");
    const use = document.createElementNS("http://www.w3.org/2000/svg", "use");
    use.setAttribute("href", "#" + svgHref);
    svg.appendChild(use);
    a.appendChild(svg);
    return a;
};

const processByline = (
    bylineNode,
    user,
    anchor,
    anchors,
    firstRun,
    self = null,
    op = null
) => {
    // don't mark self or OP more than once
    if (firstRun || !bylineNode.hasAttribute(ATTR_BYLINE)) {
        if (self !== null && user === self) markSelf(bylineNode);
        if (op !== null && user === op) markOP(bylineNode);
        bylineNode.setAttribute(ATTR_BYLINE, "");
    }

    if (anchors.length <= 1) return;

    const i = anchors.indexOf(anchor);
    const previous = anchors[i - 1];
    const next = anchors[i + 1];

    const navigator = document.createElement("span");
    navigator.setAttribute("class", "mfnr-nav");

    const nodes = ["["];
    if (previous) nodes.push(createLink(previous, "mfnr-up"));
    nodes.push(anchors.length);
    if (next) nodes.push(createLink(next, "mfnr-down"));
    nodes.push("]");

    navigator.append(...nodes);
    bylineNode.parentElement.appendChild(navigator);
};

const run = (subsite, self, firstRun) => {
    const start = performance.now();

    const opHighlight = subsite !== "ask" && subsite !== "projects"; // don't highlight OP on subsites with this built in

    // if not first run, remove any existing navigators (from both post and comments)
    if (!firstRun)
        document.querySelectorAll("span.mfnr-nav").forEach((n) => n.remove());

    // post node
    // tested on all subsites, modern and classic, 2025-04-10
    const postNode = document.querySelector(
        "div.copy > span.smallcopy > a:first-child"
    );
    const op = postNode.textContent.trim();

    // initialise with post
    const bylines = [[op, "top"]];
    const mapUsersAnchors = new Map([[op, ["top"]]]);

    // comment nodes, excluding live preview
    // tested on all subsites, modern and classic, 2025-04-10
    const commentNodes = document.querySelectorAll(
        "div.comments:not(#commentform *) > span.smallcopy > a:first-child"
    );

    for (const node of commentNodes) {
        const user = node.textContent.trim();

        const anchorElement =
            node.parentElement.parentElement.previousElementSibling;
        const anchor = anchorElement.getAttribute("name");

        bylines.push([user, anchor]);

        const anchors = mapUsersAnchors.get(user) ?? [];
        mapUsersAnchors.set(user, anchors.concat(anchor));
    }

    for (const [i, bylineNode] of [postNode, ...commentNodes].entries())
        processByline(
            bylineNode,
            bylines[i][0],
            bylines[i][1],
            mapUsersAnchors.get(bylines[i][0]),
            firstRun,
            self,
            opHighlight && i > 0 ? op : null
        );

    console.log(
        "mefi-navigator-redux",
        firstRun ? "first-run" : "new-comments",
        1 + commentNodes.length,
        Math.round(performance.now() - start) + "ms"
    );
};

(() => {
    if (
        !/^\/(\d|comments\.mefi)/.test(window.location.pathname) ||
        /rss$/.test(window.location.pathname)
    )
        return;

    document.body.insertAdjacentHTML("beforeend", SVG_UP + SVG_DOWN);
    document.body.insertAdjacentHTML("beforeend", CLASSES);

    const subsite = window.location.hostname.split(".", 1)[0];
    const self = getCookie("USER_NAME");

    const newCommentsElement = document.getElementById("newcomments");
    if (newCommentsElement) {
        const observer = new MutationObserver(() => run(subsite, self, false));
        observer.observe(newCommentsElement, { childList: true });
    }

    run(subsite, self, true);
})();