How to Render PDF in ExpressJS from Axios Response: A Step-by-Step Guide

Are you tired of struggling to render PDFs in your ExpressJS application from Axios responses? Well, worry no more! In this comprehensive guide, we’ll take you through a step-by-step process to achieve this feat. Buckle up, and let’s dive in!

What You’ll Need

• ExpressJS installed on your machine (if you haven’t already)
• Axios installed in your project (npm install axios)
• A PDF generator API or a URL that returns a PDF response
• A basic understanding of ExpressJS and Axios

Understanding the Problem

When working with APIs that return PDF responses, you might encounter difficulties rendering them directly in the browser. This is because the PDF response is not a typical HTML response, and the browser doesn’t know how to handle it.

That’s where ExpressJS and Axios come into play. By using Axios to make the API request and ExpressJS to handle the response, we can render the PDF in the browser seamlessly.

Step 1: Create an ExpressJS Route

First, let’s create an ExpressJS route that will handle the API request and response. In your ExpressJS project, create a new file (e.g., pdfRoute.js) and add the following code:

const express = require('express');
const router = express.Router();
const axios = require('axios');

router.get('/pdf', async (req, res) => {
  // API URL that returns a PDF response
  const apiUrl = 'https://api.example.com/get-pdf';

  try {
    const response = await axios.get(apiUrl, {
      responseType: 'arraybuffer'
    });

    // We'll get to this part later
    // ...
  } catch (error) {
    console.error(error);
    res.status(500).send('Error rendering PDF');
  }
});

module.exports = router;

Step 2: Set the Response Headers

In the catch block, we need to set the correct response headers to tell the browser to render the PDF correctly. Add the following code:

res.setHeader('Content-Type', 'application/pdf');
res.setHeader('Content-Disposition', 'inline; filename="example.pdf"');

The first header sets the content type to application/pdf, which tells the browser to render the response as a PDF. The second header sets the content disposition to inline, which allows the browser to render the PDF directly, and also specifies a filename for the PDF (in this case, example.pdf).

Step 3: Send the PDF Response

Finally, we need to send the PDF response to the browser. Add the following code:

res.send(Buffer.from(response.data, 'binary'));

This code takes the Axios response data and converts it into a Buffer using the binary encoding. We then send this Buffer as the response, which the browser will render as a PDF.

Putting it all Together

Here’s the complete code for the ExpressJS route:

const express = require('express');
const router = express.Router();
const axios = require('axios');

router.get('/pdf', async (req, res) => {
  const apiUrl = 'https://api.example.com/get-pdf';

  try {
    const response = await axios.get(apiUrl, {
      responseType: 'arraybuffer'
    });

    res.setHeader('Content-Type', 'application/pdf');
    res.setHeader('Content-Disposition', 'inline; filename="example.pdf"');

    res.send(Buffer.from(response.data, 'binary'));
  } catch (error) {
    console.error(error);
    res.status(500).send('Error rendering PDF');
  }
});

module.exports = router;

Testing the Route

To test the route, start your ExpressJS server and navigate to localhost:3000/pdf (or the URL you specified for the route). If everything is set up correctly, you should see the PDF rendered in the browser.

Troubleshooting Common Issues

PDF Not Rendering Correctly

If the PDF is not rendering correctly, check the following:

• Ensure that the API URL returns a valid PDF response.
• Verify that the response headers are set correctly ( Content-Type and Content-Disposition).
• Check that the Buffer is sent correctly using res.send(Buffer.from(response.data, 'binary')).

Error 500: Internal Server Error

If you’re getting an Error 500, check the following:

• Verify that the Axios request is successful and returns a valid response.
• Check the ExpressJS server logs for any error messages.
• Ensure that the route is correctly configured and routed.

Conclusion

And that’s it! You should now be able to render PDFs in your ExpressJS application from Axios responses. Remember to handle errors correctly and troubleshoot any common issues that may arise.

If you have any questions or need further clarification, feel free to ask in the comments below. Happy coding!

Keyword	Frequency
How to render pdf in expressjs from axios response	5
ExpressJS	7
Axios	5
PDF	8
Response headers	2
Buffer	2
Content-Type	2
Content-Disposition	2

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Frequently Asked Questions

Got stuck while rendering a PDF in ExpressJS from an Axios response? Worry not, friend! We’ve got you covered with these frequently asked questions.