MAL seiyuu years jQuery userscript for GreaseMonkey

// ==UserScript==
// @name        MAL seiyuu years jQuery
// @namespace   Taosique
// @version     1
// @include     http://myanimelist.net/people/*
// @require     http://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.js
// @grant       GM_xmlhttpRequest
// @grant       GM_getValue
// @grant       GM_setValue
// @noframes

/// <reference path="jquery-2.1.0-vsdoc.js" />

var specialCases = ['anime', 'manga'];

specialCases['anime'] = [];
specialCases['anime'][6055] = 1988;
specialCases['anime'][7279] = 2009;
specialCases['anime'][14467] = 2012;

specialCases['manga'] = [];
specialCases['manga'][2990] = 1996;
specialCases['manga'][5953] = 1979;
specialCases['manga'][7097] = 2004;
specialCases['manga'][7688] = 2002;
specialCases['manga'][12523] = 1986;
specialCases['manga'][25852] = 2011;
specialCases['manga'][32965] = 2010;
specialCases['manga'][35475] = 1988;
specialCases['manga'][41361] = 1988;
specialCases['manga'][53565] = 2008;
specialCases['manga'][72583] = 2014;
specialCases['manga'][88170] = 2009;
specialCases['manga'][90756] = 2011;

var entries = [];

function getGmValueKey(entryType, entryIndex) {
    return 'MAL_year_' + entryType + '_' + entryIndex;
}

$(".normal_header").each(function (index, normal_header) {
    var headerText = $(normal_header).contents().get(1);
    if (headerText) {
        var entryType = '';
        switch ($(headerText).text()) {
            case 'Voice Acting Roles':
            case 'Anime Staff Positions':
                entryType = 'anime';
                break;
            case 'Published Manga':
                entryType = 'manga';
                break;
            default:
                return;
                break;
        }
        var previousIndex;
        $(normal_header).next('table').find('tr').each(function (index, tr) {
            var a = $(tr).find('a:eq(1)');
            var entryIndex = a.attr('href').split('/', 3)[2];
            var entryGmValueKey = getGmValueKey(entryType, entryIndex);
            if (entryIndex != previousIndex) {
                previousIndex == entryIndex;
                var entryName = a.text();
                entries.push({
                    type: entryType,
                    index: entryIndex,
                    name: entryName,
                    gmValueKey: entryGmValueKey
                });
            }
            $(tr).find('td:eq(1)').after($('<td></td>', {
                id: entryGmValueKey,
                'class': 'borderClass ' + entryGmValueKey,
                width: 25,
                valign: 'top',
                nowrap: '',
                align: 'left'
            }));
        });
    }
});

var requestCount = 0;

entries.forEach(function (entry, index) {
    var year = GM_getValue(entry.gmValueKey, null);
    if (!year) {
        year = specialCases[entry.type][entry.index];
    }
    if (year && year != '0000') {
        $('.' + entry.gmValueKey).text(year);
    } else
        {
            setTimeout(function () {
                $.ajax('http://myanimelist.net/api/' + entry.type + '/search.xml?q=' + encodeURIComponent(entry.name),
                        {
/*
You can specify your username and password to avoid prompt every time:
                            username: 'UserName',
                            password: 'password#123',
*/
                            method: 'GET',
                            context: entry,
                            success: function (xml, textStatus, xhr) {
                                var contextIndex = this.index;
                                var $xmlEntry = $(xml).find('id').filter(function () { return $(this).text() == contextIndex; });
                                if ($xmlEntry.length == 1) {
                                    year = $xmlEntry.siblings('start_date:eq(0)').text().substr(0, 4);
                                    if (year) {
                                        if (year != '0000') {
                                            $('.' + entry.gmValueKey).text(year);
                                            GM_setValue(this.gmValueKey, year);
                                        }
                                    }
                                }
                            },
                        });
            }, (requestCount++) * 100);
        }
});

// ==/UserScript==