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AdBlock for Facebook

Block / Hide "Sponsored" posts on Facebook

  1. // ==UserScript==
  2. // @name         AdBlock for Facebook
  3. // @namespace    fb-adblock
  4. // @version      1.6
  5. // @description  Block / Hide "Sponsored" posts on Facebook
  6. // @author       Thor Lancaster
  7. // @match        https://www.facebook.com/*
  8. // @grant        none
  9. // ==/UserScript==
  10.  
  11. // Add abDbg=true as a URL parameter to debug ad classification
  12.  
  13. (function() {
  14.     'use strict';
  15.     var initialWait = 1500;
  16.     setTimeout(function(){
  17.     if(document.getElementById("stream_pagelet") == null){
  18.         console.log("AdBlock for Facebook currently only works on news feeds. Aborting.");
  19.         return;
  20.     }
  21.     console.log("AdBlock for Facebook running");
  22.     document.abDbg = window.location.href.includes("abDbg=true");
  23.     document.abCheckAll = false; // If true, check every post every time. Comsumes more CPU
  24.     document.abTestCheck = null; // Set to an element for debugging to determine if this script thinks it's an ad
  25.     var el = (document.getElementById("stream_pagelet"));
  26.     var feed = el.querySelectorAll('[role="feed"]')[0];
  27.     setInterval(function(f){
  28.         try{
  29.             checkAds(f);
  30.             if(document.abTestCheck != null){ // Check test element to determine whether it is an article and/or an and
  31.                 var el = document.abTestCheck;
  32.                 document.abTestCheck = null;
  33.                 if(!el.getAttribute("role") == "article"){
  34.                     console.log("Element is not an article");
  35.                 }
  36.                 if(isAd(el)){
  37.                     console.log("Element is an ad");
  38.                 } else {
  39.                     console.log("Element is not an ad");
  40.                 }
  41.             }
  42.         } catch(e){ // Log error before it is swallowed by FB's obfusicated debugging maw
  43.             console.error(e);
  44.         }
  45.     }, 2000, document);
  46.     // TODO check for ads when feed updates rather than every 2 seconds
  47.     }, initialWait);
  48.  
  49.     function checkAds(feed){
  50.         document.lastABRun = new Date().getTime();
  51.         var posts = feed.querySelectorAll('[role="article"]');
  52.         for(var x = 0; x < posts.length; x++){
  53.             var post = posts[x];
  54.             // Calculate a quick checksum so that if text changes, the post will be re-scanned
  55.             // I suspect that FB was creating non-ad posts and inserting them after a delay
  56.             // To spoof the previous version of this script
  57.             if(!post.abCheckSum || post.abCheckSum != abCheckSum(post) || document.abCheckAll){
  58.                 post.abCheckSum = abCheckSum(post);
  59.                 var isAdType = isAd(post);
  60.                 if(isAdType == 1){
  61.                     if(document.abDbg){
  62.                         markPost(post, "#F70");
  63.                     } else {
  64.                         removePost(post);
  65.                     }
  66.                 }
  67.                 // Blank post, should never happen
  68.                 else if(isAdType == -1){
  69.                     //console.log("ABCHECK blank post");
  70.                 }
  71.                 else if(isAdType == 0 && document.abDbg){
  72.                     markPost(post, "#0F7"); // for debugging
  73.                 }
  74.             }
  75.         }
  76.     }
  77.     // Color a FB post for debugging purposes
  78.     function markPost(post, color){
  79.         var els = post.querySelectorAll("*");
  80.         for(var x = 0; x < els.length; x++){
  81.             els[x].style.background = color;
  82.         }
  83.     }
  84.     function removePost(post){
  85.         post.parentElement.removeChild(post);
  86.         //post.style.height = "0px";
  87.         //post.style.opacity = "0";
  88.     }
  89.     function isAd(post){
  90.         if(post.getAttribute("aria-label") == "Comment"){ // Don't scan comments for ads
  91.             return 0;
  92.         }
  93.         var scan = post.innerText.substring(0, 128);
  94.         if(scan.length == 0){
  95.             return -1; // Blank post
  96.         }
  97.         if(scan.includes("·")){
  98.             var start = scan.substring(0, scan.indexOf("·"));
  99.             if(isSpnsrd(start)){
  100.                 //console.log("IS AN AD");
  101.                 return 1;
  102.             }
  103.         }
  104.         //console.log("IS NOT AN AD");
  105.         return 0;
  106.     }
  107.     // Scan for a string that represents "Sponsored"
  108.     var SPONSORED = "Sponsored";
  109.     function isSpnsrd(str){
  110.         var spPtr = 0;
  111.         for(var x = 0; x < str.length; x++){
  112.             var chr = str[x];
  113.             if(chr == SPONSORED[spPtr]){
  114.                 spPtr++;
  115.                 if(spPtr == SPONSORED.length){
  116.                     return true;
  117.                 }
  118.             } else {
  119.                 var toReset = true;
  120.                 if(chr == "\n"){
  121.                     toReset = false;
  122.                 } else{
  123.                     for(var y = spPtr; y >= 0; y--){
  124.                         if(chr == SPONSORED[y]){
  125.                             toReset = false;
  126.                         }
  127.                     }
  128.                 }
  129.                 if(toReset){
  130.                     spPtr = 0;
  131.                 }
  132.             }
  133.         }
  134.         return false;
  135.     }
  136.  
  137.     // Calculate the checksum of an element through it's innerText
  138.     function abCheckSum(el){
  139.         return checkSum(el.innerText);
  140.     }
  141.  
  142.     // Fast Checksum algorithm. Works great, open-source
  143.     // See https://stackoverflow.com/questions/811195/fast-open-source-checksum-for-small-strings
  144.     function checkSum(s)
  145.     {
  146.         var chk = 0x12345678;
  147.         var len = s.length;
  148.         for (var i = 0; i < len; i++) {
  149.             chk += (s.charCodeAt(i) * (i + 1));
  150.         }
  151.         return (chk & 0xffffffff).toString(16);
  152.     }
  153. })();