Facebook Posts Filter

postsfilter.user.js

// ==UserScript==
// @name Facebook Posts Filter
// @description Regex-based filter for Facebook posts, comments and likes.
// @version 1.3
// @namespace https://github.com/tkarabela
// @include http://*.facebook.com/*
// @include https://*.facebook.com/*
// @grant GM_registerMenuCommand
// @grant GM_getValue
// @grant GM_setValue
// ==/UserScript==

// ----------------------------------------------------------------------------

/*
    GreaseMonkey API polyfill

    Tested with usi 0.1.28 (https://addons.mozilla.org/en-us/firefox/addon/userunified-script-injector)

    GM_{get,set,delete,list}Value - implemented with Local Storage
    GM_registerMenuCommand - dummy implementation
*/
{
    const PREFIX = "_greasemonkey_polyfill_";

    let _GM_getValue = (name, default_) => {
        let data = window.localStorage.getItem(PREFIX + name);
        return (data !== null) ? JSON.parse(data)[0] : default_;
    }

    let _GM_setValue = (name, value) => {
        window.localStorage.setItem(PREFIX + name, JSON.stringify([value]));
    }

    let _GM_deleteValue = (name) => {
        window.localStorage.removeItem(PREFIX + name);
    }

    let _GM_listValues = () => {
        let arr = [];
        for (let i = 0; i < window.localStorage.length; i++) {
            let key = window.localStorage.key(i);
            if (key.startsWith(PREFIX)) {
                arr.push(key.substr(PREFIX.length));
            }
        }
        return arr;
    }

    let _GM_registerMenuCommand = (caption, commandFunc, accessKey, accelKey, accelModifiers) => {
        console.log("GreaseMonkey polyfill: GM_registerMenuCommand is unsupported");
    };

    if (typeof(GM_getValue) === typeof(undefined)) GM_getValue = _GM_getValue;
    if (typeof(GM_setValue) === typeof(undefined)) GM_setValue = _GM_setValue;
    if (typeof(GM_deleteValue) === typeof(undefined)) GM_deleteValue = _GM_deleteValue;
    if (typeof(GM_listValues) === typeof(undefined)) GM_listValues = _GM_listValues;
    if (typeof(GM_registerMenuCommand) === typeof(undefined)) GM_registerMenuCommand = _GM_registerMenuCommand;
}

// ----------------------------------------------------------------------------

const INITIAL_DELAY = 500;
const REFRESH_INTERVAL = 2000;

const IMPOSSIBLE_REGEX = /.^/;
const PATTERN_STORAGE_KEY = "pattern";
const CHECKED_CLASS = "_FBPOSTFILTER_CHECKED";
const SETTINGS_LINK_ID = "_FBPOSTFILTER_SETTINGS_LINK";

var pattern = new RegExp(GM_getValue(PATTERN_STORAGE_KEY, IMPOSSIBLE_REGEX));
var hiddenCount = 0;

// ----------------------------------------------------------------------------

let hidePredicate = (node) => node.textContent.search(pattern) != -1;
let uncheckedPredicate = (node) => !node.classList.contains(CHECKED_CLASS);

function main() {
    addSettingsButton();

    let examinedNodes = [];
    let nodesToHide = [];

    let posts = [...document.querySelectorAll("div[role='article'] > div:first-child, article > div:first-child")].filter(uncheckedPredicate);
    examinedNodes.push(...posts);
    nodesToHide.push(...posts.filter(hidePredicate).map(node => node.parentNode));

    let comments = [...document.querySelectorAll("li.UFIComment")].filter(uncheckedPredicate);
    examinedNodes.push(...comments);
    nodesToHide.push(...comments.filter(hidePredicate));

    let likes = [...document.querySelectorAll("a.profileLink, .like_def a")].filter(uncheckedPredicate);
    examinedNodes.push(...likes);
    nodesToHide.push(...likes.filter(hidePredicate));

    examinedNodes.forEach(node => node.classList.add(CHECKED_CLASS));

    if (nodesToHide.length > 0) {
        hiddenCount += nodesToHide.length;
        console.log("Hidden some items:", nodesToHide);
        nodesToHide.forEach(node => node.hidden = true);
        
        let settingsLink = document.getElementById(SETTINGS_LINK_ID);
        if (settingsLink) {
            settingsLink.title = `FB Posts Filter – settings (hidden objects: ${hiddenCount})`;
        }
    }

    setTimeout(main, REFRESH_INTERVAL);
}

function changeSettings() {
    let oldSrc = pattern.source;
    let newSrc = prompt("Please enter regex pattern for posts/comments to be hidden.\n(Example: keyword1|keyword2)", oldSrc);

    if (newSrc === null) return; // prompt closed

    try {
        if (/^\s*$/.test(newSrc)) throw "Pattern must not be empty!\n(Would match anything.)";

        pattern = new RegExp(newSrc);
        GM_setValue(PATTERN_STORAGE_KEY, newSrc);
        console.log("Changed pattern to:", newSrc);
    } catch (e) {
        alert(`Error: ${e}`);
    }
}

function addSettingsButton() {
    if (document.getElementById(SETTINGS_LINK_ID)) return;

    let link = document.createElement("a");
    link.id = SETTINGS_LINK_ID;
    link.innerHTML = "&pi;";
    link.title = "FB Posts Filter – settings";
    link.onclick = changeSettings;
    link.style.fontFamily = "serif";
    link.style.display = "block";
    link.style.float = "right";

    let regularFooter = document.querySelector(".rhcFooterCopyright");
    let mobileFooter = null; // FIXME

    if (regularFooter) {
        regularFooter.appendChild(link);
        console.log("Added settings link (desktop)");
    } else if (mobileFooter) {
        mobileFooter.appendChild(link);
        console.log("Added settings link (mobile)");
    }
}

// ----------------------------------------------------------------------------

GM_registerMenuCommand("FB Posts Filter – settings", changeSettings);
setTimeout(main, INITIAL_DELAY);