使用eKoopmans html2pdf（new-api分支）邮件发送PDF遇问题求助

Hey there, I get it—working with libraries like html2pdf when you’re not a full-time developer can feel tricky, especially when tying it to email functionality. Since your code snippet cuts off, let’s walk through the most common hurdles and practical fixes for using the new-api branch of html2pdf to generate PDFs and send them via email.

1. Fixing Basic PDF Generation #

First, let’s make sure your core html2pdf setup is solid. The new-api uses a promise-based workflow, so your code needs to handle that correctly. Here’s a complete, corrected example of generating the PDF properly:

$(document).ready(function(){
  $("#cmd").click(async function(){
    try {
      const signaturefilename = $('#auftragsnummer').val();
      const element = document.getElementById('PDFcontent'); // Replace with your target element ID
      
      // Generate PDF using new-api's promise-based methods
      const pdfBlob = await html2pdf()
        .from(element)
        .set({
          filename: `${signaturefilename}.pdf`,
          margin: 10,
          image: { type: 'jpeg', quality: 0.98 },
          html2canvas: { scale: 2 }, // Ensures high-resolution output
          jsPDF: { unit: 'mm', format: 'a4', orientation: 'portrait' }
        })
        .output('blob'); // Output as Blob (ideal for email attachments)
      
      // Pass the generated PDF to your email function
      sendEmailWithAttachment(pdfBlob, signaturefilename);
    } catch (error) {
      console.error('PDF generation failed:', error);
      alert('Oops, something went wrong creating your PDF! Check the browser console for details.');
    }
  });
});

Key notes for non-pros:

• Use async/await to wait for the PDF to finish generating (the new-api relies on promises, so skipping this will break things).
• The catch block helps you debug issues—check your browser’s developer console for error messages if something fails.
• Outputting as a blob makes it easy to attach the PDF to emails later.

2. Sending the PDF via Email #

Client-side email sending has big limitations (most browsers block direct mailto: links with large attachments), so a backend approach is the most reliable option. Here are both paths:

Option A: Backend Integration (Recommended) #

If you have a simple backend (like Node.js/Express, PHP, or Python), you can send the PDF Blob to it, then let the backend handle sending the email.

Client-side code to send the PDF to your backend:

function sendEmailWithAttachment(pdfBlob, filename) {
  const formData = new FormData();
  formData.append('pdf', pdfBlob, `${filename}.pdf`);
  formData.append('to', 'recipient@example.com');
  formData.append('subject', `Your Document: ${filename}`);
  
  // Replace '/send-email' with your backend endpoint URL
  fetch('/send-email', {
    method: 'POST',
    body: formData
  })
  .then(response => response.json())
  .then(data => {
    data.success ? alert('Email sent successfully!') : alert('Failed to send email.');
  })
  .catch(error => console.error('Email send error:', error));
}

Example backend code (Node.js/Express with Nodemailer):

const express = require('express');
const multer = require('multer');
const nodemailer = require('nodemailer');
const app = express();
const upload = multer(); // Handles file uploads

app.post('/send-email', upload.single('pdf'), async (req, res) => {
  try {
    // Set up your email transporter (use Gmail, SendGrid, or another service)
    const transporter = nodemailer.createTransport({
      service: 'Gmail',
      auth: {
        user: 'your-email@example.com',
        pass: 'your-app-specific-password' // Use an app password for Gmail
      }
    });
    
    const mailOptions = {
      from: 'your-email@example.com',
      to: req.body.to,
      subject: req.body.subject,
      text: 'Attached is your requested document.',
      attachments: [{
        filename: req.file.originalname,
        content: req.file.buffer
      }]
    };
    
    await transporter.sendMail(mailOptions);
    res.json({ success: true });
  } catch (error) {
    console.error('Backend email error:', error);
    res.json({ success: false, error: error.message });
  }
});

app.listen(3000, () => console.log('Server running on port 3000'));

Option B: Client-Side (Limited) #

If you can’t use a backend, you can try generating a data URI for the PDF and using it with a mailto: link. Note: This often fails with larger PDFs and isn’t reliable across all browsers.

function sendEmailWithAttachment(pdfBlob, filename) {
  const reader = new FileReader();
  reader.onload = function(e) {
    const dataUri = e.target.result;
    const mailtoLink = `mailto:recipient@example.com?subject=Your Document: ${filename}&body=Here's your document.&attachment=${encodeURIComponent(dataUri)}`;
    window.location.href = mailtoLink;
  };
  reader.readAsDataURL(pdfBlob);
}

3. Common Pitfalls to Avoid #

• Forgetting async/await: The new-api uses promises, so skipping these will lead to undefined PDF data.
• Wrong element selection: Double-check that document.getElementById('PDFcontent') targets the correct HTML element containing your document.
• CORS errors: If using a backend, make sure your server sends CORS headers to allow requests from your frontend.
• Ignoring error logs: Always check your browser’s developer console for error messages—they’ll tell you exactly where things went wrong.

If you can share the rest of your code or specific error messages you’re seeing, I can help narrow down the issue even further!

内容的提问来源于stack exchange，提问作者Jochen Schächtele