exhentai tag userscript

// ==UserScript==
// @name         Tag Previewer
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Preview tags
// @author       Anon
// @include      /^(http(s)?://)?exhentai.org/?.*/
// @grant        none
// @require      https://code.jquery.com/jquery-3.4.0.min.js
// ==/UserScript==

$(document).ready(function() {
    // first selector is for thumbnail view, second is for extended
    $( "div.gl1t, td.gl1e" ).each( function( index, element ){
        // combined namespace + all tags into one string to display at end
        var combined = "";
        // store the link to the actual doujin so we can pull tags
        var href = $(element).find('a').attr('href');
        // store the img since we will modify its title later
        var img = $(element).find('img');
        // delay is in ms, timeout is so we don't instally pull tags when we mouse over stuff
        var delay=1, setTimeoutConst;
        var loaded = false;
        $(img).on("mouseenter", function() {
            // if alread pulled tags, don't do it again. be nice to their servers
            if (loaded) {
                return;
            }
            // start a timer, once 'delay' ms have happened, get tags
            setTimeoutConst = setTimeout(function() {
                       $.ajax({
                           // make a get request to the doujin page to pull tags
                           url: href,
                           type: 'GET',
                           success: function(res) {
                               // get the parent element of each namespace + list of tags
                               $(res).find('div#taglist table tbody tr').each( function( index, element ) {
                                   // separate namespace and tags since we add to the string differently
                                   var namespace = $(element).find('td.tc');
                                   var tag = $(element).find("div");
                                   combined += $(namespace).text() + ' ';
                                   // iterate tags and add to string
                                   $(tag).each(function( index, element ) {
                                       combined += $(element).text() + ', ';
                                   });
                                   //strip last ', ' and add a newline
                                   combined = combined.substring(0, combined.length - 2) + '\n';
                               });
                               //strip the last '\n'
                               combined = combined.substring(0, combined.length - 1);
                               $(img).prop('title', combined);
                           }
                       });
                loaded = true;
            }, delay);
        }).on("mouseleave", function() {
            // if we moved mouse out of image before 'delay' ms, reset the timer
            clearTimeout(setTimeoutConst);
        });
    });
});