The Mysterious Case of the Vanishing PDF: Solving the “PDF is not displayed in my React Native Expo project” Conundrum

Are you tired of wrestling with the elusive PDF rendering issue in your React Native Expo project? Are you left scratching your head, wondering why your beautifully crafted PDF refuses to materialize on your mobile device? Fear not, dear developer, for we’re about to embark on a thrilling adventure to conquer this enigmatic problem once and for all!

What’s Going On Here?

Before we dive into the solution, let’s take a step back and understand the root cause of this issue. When you try to display a PDF in your React Native Expo project, the app might not render it correctly, or worse, not display it at all. This can be attributed to several reasons:

• Limited Support for PDFs in React Native Expo: Unfortunately, React Native Expo doesn’t provide built-in support for rendering PDFs out of the box. This means you need to find alternative solutions to make it work.
• Platform-Specific File Handling: PDF files require specific handling on both iOS and Android platforms. Expo’s built-in file handling might not be sufficient to handle these platform-specific requirements.
• External Library Integration: To display PDFs, you’ll need to integrate an external library that can handle PDF rendering. This might lead to compatibility issues or conflicts with your existing project setup.

The Solution: A Step-by-Step Guide

Now that we’ve pinpointed the possible causes, let’s create a PDF-friendly React Native Expo project. Follow these steps to the letter, and you’ll be displaying PDFs like a pro in no time!

Step 1: Install the Required Libraries

To render PDFs, we’ll use the excellent react-native-pdf library. Install it using the following command:

npm install react-native-pdf

Additionally, we’ll need the expo-file-system library to handle file-related tasks:

expo install expo-file-system

Step 2: Set Up Your Project Structure

Create a new folder in your project directory, and name it pdfs. This will hold our sample PDF file:

mkdir pdfs

Inside the pdfs folder, add a sample PDF file, e.g., sample.pdf. You can download a sample PDF from the internet or create your own.

Step 3: Create a PDF Viewer Component

Create a new JavaScript file, e.g., PDFViewer.js, and add the following code:

import React, { useState, useEffect } from 'react';
import { View, ActivityIndicator } from 'react-native';
import { Document, Page } from 'react-native-pdf';

const PDFViewer = ({ source }) => {
  const [pdf, setPdf] = useState(null);
  const [isLoading, setIsLoading] = useState(true);

  useEffect(() => {
    const loadPdf = async () => {
      const { uri } = await Expo.FileSystem.downloadAsync(
        Expo.FileSystem.documentDirectory + 'pdfs/sample.pdf',
        Expo.FileSystem.cacheDirectory + 'pdfs/sample.pdf'
      );
      setPdf(uri);
      setIsLoading(false);
    };
    loadPdf();
  }, []);

  return (
    
      {isLoading ? (
        
      ) : (
         {
            console.log(`Number of pages: ${numberOfPages}`);
          }}
          onError={(error) => {
            console.log('Error loading PDF:', error);
          }}
        >
          
        
      )}
    
  );
};

export default PDFViewer;

Step 4: Integrate the PDF Viewer Component

Now, let’s integrate our shiny new PDFViewer component into our app. Create a new JavaScript file, e.g., App.js, and add the following code:

import React from 'react';
import { View, Text } from 'react-native';
import PDFViewer from './PDFViewer';

const App = () => {
  return (
    
      PDF Viewer Demo
      
    
  );
};

export default App;

Step 5: Configure Expo to Handle PDFs

In your app.json file, add the following configuration:

{
  "expo": {
    ...
    "assetBundlePatterns": ["**/*"],
    ...
  }
}

This tells Expo to include the PDF file in the asset bundle when building the app.

Common Issues and Troubleshooting

As you embark on this PDF adventure, you might encounter some common issues. Don’t worry, we’ve got you covered!

Issue	Solution
PDF not rendering on iOS	Ensure you’ve added the ios.useFrameworks! property in your app.json file. This enables the use of native frameworks on iOS.
PDF not rendering on Android	Check if you’ve correctly installed the react-native-pdf library. Make sure to run npm install react-native-pdf and then rebuild your project.
PDF file not found	Verify that the PDF file is correctly placed in the pdfs folder and that the file name matches the one specified in the PDFViewer component.

Conclusion

Voilà! You now possess the magical powers to conjure PDFs in your React Native Expo project. Remember to stay calm, methodical, and patient when tackling this challenge. With these step-by-step instructions, you’ll be displaying PDFs like a pro in no time.

What’s next? Experiment with different PDF rendering libraries, explore advanced PDF features, and unlock the full potential of your React Native Expo project!

Happy coding, and may the PDF force be with you!

Here are 5 Questions and Answers about “PDF is not displayed in my react native expo project” in a creative voice and tone:

Frequently Asked Question

Having trouble displaying PDFs in your React Native Expo project? We’ve got you covered! Check out these frequently asked questions to get your PDFs up and running in no time.