Exam Papers Link Extractor for https://exampapers-ta-tudublin-ie.tudublin.idm.oclc.org/

epe.userscript.js

// ==UserScript==
// @name         Exam Papers Link Extractor
// @namespace    http://tampermonkey.net/
// @version      2024-01-01
// @description  Extracts links from the exam papers website and displays them in a popup window.
// @author       https://git.grzegorz.ie/
// @match        *://exampapers-ta-tudublin-ie.tudublin.idm.oclc.org/*
// @require      https://cdn.jsdelivr.net/npm/jszip@3.10.1/dist/jszip.min.js
// @icon         https://www.google.com/s2/favicons?sz=64&domain=oclc.org
// @grant        none
// ==/UserScript==

(() => {
    'use strict';

    console.log('Exam Papers Link Extractor loaded.');


    /**
     * A button is added to each main entry in the treeview to extract links for that module.
     * id="treeview-searchable"
     */
    let module = '', course = '';
    const departments = json4.map(e => e.text);
    console.log(departments);

    const course_dropdown = document.createElement('select');
    course_dropdown.style.marginLeft = '20px';
    course_dropdown.addEventListener('change', () => course = course_dropdown.value);
    departments.forEach(e => {
        const option = document.createElement('option');
        option.textContent = e;
        course_dropdown.appendChild(option);
    });

    const search_box = document.createElement('input');
    search_box.type = 'text';
    search_box.placeholder = 'Module title';
    search_box.style.marginLeft = '20px';
    search_box.addEventListener('input', () => module = search_box.value);

    const button = document.createElement('button');
    button.textContent = 'Extract links';
    button.style.marginLeft = '20px';
    button.addEventListener('click', () => {
        console.log('Extracting links for', course, module);
        extract(course, module);
    });


    // -- Create a download button
    const download_button = document.createElement('button');
    download_button.textContent = 'Download links';
    download_button.style.marginTop = '20px';
    download_button.addEventListener('click', async() => {
        console.log('Downloading links...');

        // -- Check if the course exists
        const selected_nodes = json4.find(e => e.text.toLowerCase() === course.toLowerCase());
        if (!selected_nodes) return console.error('No course found.');

        // -- Get all the links for the module
        const links = [];
        selected_nodes.nodes.forEach((n1) => n1.nodes.forEach((n2) => n2.nodes.forEach((n3) => (n3?.nodes ?? []).forEach((n4) => {
            if(n4.text.toLowerCase().includes(module.toLowerCase()) && links.indexOf(n4) === -1) links.push(n4);
        }))));


        // -- Create a zip file
        const zip = new JSZip();
        let readmefile = `# ${course} - ${module}\n\n`;


        // -- Donwload all the pdfs
        const promises = [];
        links.forEach(link => {
            const filename = link.text.replace(/[^a-z0-9]/gi, '_').toLowerCase(),
                download_promise = download(`https://exampapers-ta-tudublin-ie.tudublin.idm.oclc.org/${link.href}`, filename);

            // -- Add the filename to the readme file
            readmefile += `* [${filename}](./${filename}.pdf)\n`;

            // -- Add the download promise to the array
            promises.push(download_promise);
            console.log(`Downloading (0/1) ${filename}`);
            download_promise.then((pdf) => {
                console.log(`Downloaded (1/1) ${filename}`);

                // -- Add the pdf to the zip file
                zip.file(`${filename}.pdf`, pdf);
            });
        });


        // -- Wait for all the downloads to finish
        await Promise.all(promises);
        console.log('All downloads finished.');
        readmefile += `\n\n ${promises.length} files downloaded at ${new Date().toLocaleString()}`;

        // -- Add the readme file to the zip file
        zip.file('README.md', readmefile);


        // -- Generate the zip file and download it
        zip.generateAsync({type: 'blob'}).then(content => {
            const a = document.createElement('a');
            a.href = URL.createObjectURL(content);
            a.download = `pdf_${course}_${module}.zip`.replace(/[^a-z0-9]/gi, '_').toLowerCase();
            a.click();
        });
    });


    const tree = document.querySelector('.jumbotron');
    tree.appendChild(download_button, tree.firstChild);
    tree.appendChild(button, tree.firstChild);
    tree.appendChild(search_box, tree.firstChild);
    tree.appendChild(course_dropdown, tree.firstChild);


    /**
     * Main part of the script that actually does the work.
     */
    const extract = (
        course,
        module
    ) => {

        // -- Check if the course exists
        const selected_nodes = json4.find(e => e.text.toLowerCase() === course.toLowerCase());
        if (!selected_nodes) return console.error('No course found.');

        // -- Get all the links for the module
        const links = [];
        selected_nodes.nodes.forEach((n1) => n1.nodes.forEach((n2) => n2.nodes.forEach((n3) => (n3?.nodes ?? []).forEach((n4) => {
            if(n4.text.toLowerCase().includes(module.toLowerCase()) && links.indexOf(n4) === -1) links.push(n4);
        }))));



        // -- Create a popup with the links
        const popup = (links, style = `
            table{width:100%;border-collapse:collapse;margin-top:20px;}
            th,td{border:1px solid#ddd;padding:8px;text-align:left;}
            th{background-color: #f2f2f2;}`
        ) => {
            // -- Create a style element and append it to the head
            const style_element = document.createElement('style');
            style_element.textContent = style;
            document.head.appendChild(style_element);



            // -- Create a table element
            const table = document.createElement('table');

            // -- Create table header
            const thead = table.createTHead(),
                header_row = thead.insertRow(),
                header1 = header_row.insertCell(0),
                header2 = header_row.insertCell(1);
            header1.textContent = 'Text';
            header2.textContent = 'Link';

            // -- Create table body
            const tbody = table.createTBody();

            // -- Populate the table with data from the links array
            links.forEach(link => {
                const row = tbody.insertRow(),
                    cell1 = row.insertCell(0),
                    cell2 = row.insertCell(1);

                cell1.textContent = link.text;
                cell2.innerHTML = `<a href="https://exampapers-ta-tudublin-ie.tudublin.idm.oclc.org/${link.href}" target="_blank">${link.href}</a>`;
            });


            // -- Open a popup with the table
            const popup = window.open('', 'Popup', 'width=600,height=400');
            popup.document.write('<html><head><title>Links Table</title>');
            popup.document.write(`<style>${style}</style>`);
            popup.document.write('</head><body>');
            popup.document.write('<h2>Links Table</h2>');
            popup.document.write(table.outerHTML);
            popup.document.write('</body></html>');
        };

        popup(links);
    };



    const download = (url, filename) => {
        // -- Downloads the pdf and returns a promise for that pdf
        return new Promise((resolve, reject) => {
            const xhr = new XMLHttpRequest();
            xhr.open('GET', url, true);
            xhr.responseType = 'blob';
            xhr.onload = () => {
                if (xhr.status === 200) {
                    const blob = xhr.response;
                    resolve(blob);
                } else {
                    reject(xhr.statusText);
                }
            };
            xhr.onerror = () => reject(xhr.statusText);
            xhr.send();
        });

    };
})();