arXiv title fixer

arXiv_titlatorizer.js

// ==UserScript==
// @name         Arxiv titlatorizer
// @namespace    Titlatorizer
// @version      0.1
// @description  Set correct tab <title> on arXiv pages.
// @author       Tianshu Wang
// @match        https://arxiv.org/pdf/*
// @grant        GM_xmlhttpRequest
// ==/UserScript==
//
// Based on
// https://github.com/musically-ut/arXiv-title-fixer &
// https://gist.github.com/o-jasper/df6f93e8c1a9ec8d3ff59f0266dfe368
// (c) 2021 Tianshu Wang
// This code is licensed under MIT license
//

(function() {
    'use strict';

    const TITLE_PLACEHOLDER = 'Unknown title.';

    function getPaperTitleFromResponse(feed) {
        var paperTitle = null;
        Array.prototype.slice.call(feed.children).forEach(function (child) {
            if (child.nodeName.toLowerCase() === 'entry') {
                var entry = child;
                Array.prototype.slice.call(entry.children).forEach(function (field) {
                    if (field.nodeName.toLowerCase() === 'title') {
                        var title = field;
                        paperTitle = title.childNodes[0].wholeText;
                    }
                });
            }
        });

        return (paperTitle === null) ? TITLE_PLACEHOLDER : paperTitle;
    }

    function addTitleToHead(paperTitle) {
        var title = document.createElement('title');
        title.appendChild(document.createTextNode(paperTitle));

        var head = null;
        if (document.head) {
            Array.prototype.slice.call(document.head.children).forEach(function (child) {
                if (child.nodeName.toLowerCase() === 'title') {
                    document.head.removeChild(child);
                }
            });
            document.head.appendChild(title);
        } else {
            head = document.createElement('head');
            head.appendChild(title);
            var html = document.body.parentElement;
            html.insertBefore(head, document.body);
        }
    }

    var paperId = null;
    try {
        var pathComponents = window.location.pathname.split('/');
        var pdfName = pathComponents[pathComponents.length - 1];
        paperId = /([^v]*)(v[0-9]*)?\.pdf/.exec(pdfName)[1];
    } catch(e) {
        console.warn('Could not get submission ID. Error: ', e);
    }

    if (paperId !== null) {
        GM_xmlhttpRequest({
            method:'GET',
            url:"http://export.arxiv.org/api/query?id_list=" + paperId,
            onload:function (response) {
                if (response.status === 200) {
                    var responseXML = (new DOMParser()).parseFromString(response.responseText, "text/xml");
                    var paperTitle = getPaperTitleFromResponse(responseXML.childNodes[0]);
                    addTitleToHead(paperTitle);
                };
            }
        });
    }
})();