Greasemonkey YouTube Tag Section

youtubetags.user.js

// ==UserScript==
// @name        YouTube Tag Section
// @namespace   IllidanS4/YouTubeTags
// @description Adds Tag option to section type menu.
// @include     https://www.youtube.com/channel/*
// @include     https://www.youtube.com/user/*
// @version     1
// @grant       none
// ==/UserScript==

setInterval(function(){
    var elems = document.getElementsByName("shelf_type_id");
    for(var i = 0; i < elems.length; i++)
    {
        var elem = elems[i];
        var lastoptg = elem.children[elem.children.length-1];
        if(lastoptg.children[lastoptg.children.length-1].value != 140)
        {
            var opt = document.createElement("option");
            opt.setAttribute("value", "140");
            opt.setAttribute("data-duplicates-allowed", "True");
            opt.innerHTML = "Tag";
            lastoptg.appendChild(opt);
        }
    }
}, 500);