tempermonkey script : Serialize and display Danbooru tags

injection_tags.user.js

// ==UserScript==
// @name         injection tags
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description  Serialize and display Danbooru tags
// @author       lowteq
// @match        https://danbooru.donmai.us/posts/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=donmai.us
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    var tagElements = document.querySelectorAll("li.tag-type-0[data-tag-name]");
    var dataTagNames = Array.from(tagElements).map(element => element.getAttribute("data-tag-name"));

    var artistElements = document.querySelectorAll("li.tag-type-1[data-tag-name]");
    var artistTagNames = Array.from(artistElements).map(element => element.getAttribute("data-tag-name"));

    var copyrightElements = document.querySelectorAll("li.tag-type-3[data-tag-name]");
    var copyrightTagNames = Array.from(copyrightElements).map(element => element.getAttribute("data-tag-name"));

    var characterElements = document.querySelectorAll("li.tag-type-4[data-tag-name]");
    var characterTagNames = Array.from(characterElements).map(element => element.getAttribute("data-tag-name"));

    var headerTagsString = [...artistTagNames, ...copyrightTagNames, ...characterTagNames].join(",").replace(/_/g, " ");
    var dataTagNamesString = dataTagNames.join(',').replace(/_/g, " ");
    var content = document.getElementById("content");
    content.insertAdjacentHTML("afterbegin", `<div>${headerTagsString}</div></br><div>${dataTagNamesString}</div>`);
})();