<a id="downloadBtn" href="assets/2_5m_ruler.pdf" download> <button disabled>Download 2.5 m file</button> </a>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>✦ X‑X‑X → 2.5 m Download</title> <style> body font-family: Arial, sans-serif; max-width: 500px; margin:2rem auto; .valid color: green; .invalid color: red; button:disabled opacity:0.5; cursor:not-allowed; </style> </head> <body> <h2>X‑X‑X → 2.5 m Download</h2> x-x-x is equal to 2 5 meter download link
document.getElementById('validateBtn').addEventListener('click', validate); // optional live validation: // document.getElementById('expr').addEventListener('input', validate); </script> </body> </html> If you need to generate the file on the fly (e.g., a PDF ruler with custom branding), a simple endpoint could be: <a id="downloadBtn" href="assets/2_5m_ruler
| Tech | Example | |------|---------| | | GET /download?length=2.5 → uses pdfkit to render a 2.5 m ruler PDF, streams it back. | | Python/Flask | @app.route('/download') → builds an SVG/PNG with cairosvg . | | Static CDN | Store the file once ( 2_5m_ruler.pdf ) and serve via CloudFront, Akamai, etc. | | <p id="msg"></p>
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