WP Manifestindependent plugin directory
manifest / performance / pdf-lazy-loader

PDF Lazy Loader

Defers PDF Embedder output behind a lightweight click-to-load facade with optional Cloudflare Turnstile check. No PDF/viewer assets are loaded until the visitor clicks "View PDF".

by Your TM · github.com/gemuzkm/pdf-lazy-loader · website

★ 0stars

Install

Download source zip No release zip yet

This is the repository archive. It installs, but the folder name will carry the branch suffix and updates will not flow.

Install straight from GitHub with WP-CLI:

wp plugin install https://github.com/gemuzkm/pdf-lazy-loader/archive/refs/heads/main.zip
No built-in updater. New versions won't appear under Dashboard → Updates. Install new releases yourself, or let Git Updater track the repository.
Readme github.com/gemuzkm/pdf-lazy-loader ↗

PDF Lazy Loader v1.3.1

WordPress plugin that defers PDF Embedder / PDF Embedder Premium output behind a lightweight click-to-load facade. Nothing PDF-related — viewer iframe, PDF file, viewer CSS/JS — is requested until the visitor clicks View PDF (and, optionally, passes Cloudflare Turnstile). This keeps pages light and hides PDFs from naive bots.

Features

  • Server-rendered facade: the placeholder is part of the HTML (the_content filter) — visible before any JS runs, no layout shift (CLS), page-cache friendly
  • Zero PDF assets on page load: PDF Embedder CSS/JS (including pdfemb-fullscreen.min.css enqueued inside Viewer::render()) are captured and loaded only on click
  • Localized data preserved: wp_localize_script() / wp_add_inline_script() data attached to PDF Embedder handles (e.g. pdfemb_trans) is carried over, so deferred scripts work exactly as when loaded normally
  • Fast click-to-view: minimum spinner time runs in parallel with asset loading (default 300 ms); static viewer assets are preloaded on hover / focus / touch
  • Cloudflare Turnstile: optional verification before the PDF loads (widget script is also preloaded on intent)
  • Server-side Turnstile verification (optional): token checked via Cloudflare siteverify; the page contains only an AES-256-GCM encrypted reference, the PDF URL is released by a REST endpoint after verification
  • URL obfuscation: iframe src is replaced by an XOR + Base64 copy in data-pdf-lazy-original-src-enc
  • Responsive facade: heights per breakpoint via CSS custom properties and @media (no resize listeners)
  • Accessible by default (WCAG AA): button/icon colors are auto-darkened (same hue) until white text reaches 4.5:1; all facade texts meet 4.5:1; no heading tags in the facade (does not break the page heading outline)
  • No render-blocking request: facade CSS (~3 KB) is inlined in <head>; frontend JS is minified (pdf-lazy-loader.min.js, ~4 KB gzip) and deferred
  • Download button (optional), Debug mode, translatable strings (pdf-lazy-loader text domain)
  • WordPress 7.x: tested up to 7.1, requires PHP 7.4+, script tags via wp_get_inline_script_tag() (CSP-nonce friendly), frontend JS with defer strategy

How It Works

Page Load (before user interaction)

  1. Detection — pdf_lazy_loader_has_pdf_iframes() checks every post of the main query (single pages, blog index, archives, search). Result is memoized per request (tri-state); pages without PDF are not touched at all — no CSS/JS/inline script from this plugin is printed there
  2. the_content:999 — each PDF iframe gets its src removed (obfuscated copy kept in a data attribute), the class pll-iframe-hidden, and a server-side facade is printed right before it
  3. Layer 1 — wp_enqueue_scripts:999: queued PDF Embedder styles/scripts are collected (final URL incl. ?ver=, deps in order, localized data, inline before/after) and dequeued
  4. Layer 2 — wp_footer:1: same collection after all shortcodes ran — catches pdf-fullscreen (pdfemb-fullscreen.min.css) enqueued inside Viewer::render()
  5. ob_start — template_redirect:1: one preg_replace_callback pass strips any PDF Embedder <link>/`