MeFi Navigator Redux

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

当前为 2025-08-14 提交的版本,查看 最新版本

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

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

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name         MeFi Navigator Redux
// @namespace    https://github.com/klipspringr/mefi-userscripts
// @version      2025-08-14-a
// @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==

(() => {
    "use strict";

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

    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"
        );
    };

    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);
})();