PDF Viewer Embedder

Embeds PDFs directly in the page instead of downloading, with fallback and cleanup

Ajankohdalta 29.4.2025. Katso uusin versio.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         PDF Viewer Embedder
// @namespace    *
// @version      1.6
// @author       zinchaiku
// @description  Embeds PDFs directly in the page instead of downloading, with fallback and cleanup
// @match        *://*/*
// @grant        none
// @license      MIT
// ==/UserScript==

(function () {
    'use strict';

    let currentBlobUrl = null;

    function showPDF(srcUrl, isBlob = false) {
        const existing = document.getElementById('tampermonkey-pdf-viewer');
        if (existing) existing.remove();

        const overlay = document.createElement('div');
        overlay.id = 'tampermonkey-pdf-viewer';
        overlay.style.position = 'fixed';
        overlay.style.top = 0;
        overlay.style.left = 0;
        overlay.style.width = '100vw';
        overlay.style.height = '100vh';
        overlay.style.background = 'rgba(0,0,0,0.8)';
        overlay.style.zIndex = 99999;
        overlay.style.display = 'flex';
        overlay.style.alignItems = 'center';
        overlay.style.justifyContent = 'center';

        const iframe = document.createElement('iframe');
        iframe.src = srcUrl;
        iframe.style.width = '80vw';
        iframe.style.height = '90vh';
        iframe.style.border = 'none';
        iframe.style.background = '#fff';
        overlay.appendChild(iframe);

        // Fallback if iframe fails to load (e.g. X-Frame-Options)
        iframe.onerror = () => {
            overlay.remove();
            if (isBlob && currentBlobUrl) {
                URL.revokeObjectURL(currentBlobUrl);
                currentBlobUrl = null;
            }
            window.open(srcUrl, '_blank');
        };

        const closeBtn = document.createElement('button');
        closeBtn.textContent = 'Close PDF';
        closeBtn.style.position = 'absolute';
        closeBtn.style.top = '20px';
        closeBtn.style.right = '40px';
        closeBtn.style.zIndex = 100000;
        closeBtn.style.padding = '2px 6px';
        closeBtn.style.fontSize = '1.2em';
        closeBtn.onclick = () => {
            overlay.remove();
            if (isBlob && currentBlobUrl) {
                URL.revokeObjectURL(currentBlobUrl);
                currentBlobUrl = null;
            }
        };
        overlay.appendChild(closeBtn);

        document.body.appendChild(overlay);

        // Track for cleanup
        if (isBlob) {
            currentBlobUrl = srcUrl;
        } else {
            currentBlobUrl = null;
        }
    }

    function isPDFLink(href) {
        try {
            const url = new URL(href, window.location.href);
            return url.pathname.toLowerCase().endsWith('.pdf');
        } catch {
            return false;
        }
    }

    function attachPDFInterceptors() {
        document.querySelectorAll('a[href]').forEach(link => {
            const href = link.getAttribute('href');
            if (!href || link.dataset.tmPdfBound) return;

            const isWrapper = href.includes('_download.html');
            const isDirectPDF = isPDFLink(href);

            if (isWrapper || isDirectPDF) {
                link.dataset.tmPdfBound = "1";

                link.addEventListener('click', function (e) {
                    e.preventDefault();

                    if (isDirectPDF) {
                        showPDF(link.href);
                    } else {
                        fetch(link.href, { credentials: 'include' })
                            .then(res => {
                                const contentType = res.headers.get('Content-Type') || '';
                                if (contentType.includes('pdf')) {
                                    return res.blob().then(blob => {
                                        const blobUrl = URL.createObjectURL(blob);
                                        showPDF(blobUrl, true);
                                    });
                                } else {
                                    window.location.href = link.href;
                                }
                            })
                            .catch(err => {
                                alert("Could not open PDF: " + err);
                                window.location.href = link.href;
                            });
                    }
                });
            }
        });
    }

    window.addEventListener('keydown', (e) => {
        if (e.key === 'Escape') {
            const viewer = document.getElementById('tampermonkey-pdf-viewer');
            if (viewer) {
                viewer.remove();
                if (currentBlobUrl) {
                    URL.revokeObjectURL(currentBlobUrl);
                    currentBlobUrl = null;
                }
            }
        }
    });

    attachPDFInterceptors();
    const observer = new MutationObserver(attachPDFInterceptors);
    observer.observe(document.body, { childList: true, subtree: true });
})();