MeFi Navigator Redux

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

目前為 2025-08-14 提交的版本,檢視 最新版本

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

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

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==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);
})();