How to Create a PHP HTML PDF Generator
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Generating PDFs from HTML content is a common task in web development.
Whether it’s generating invoices, reports, or downloadable content, converting dynamic HTML ]supplied from a user form to PDF helps in delivering formatted documents to users.
While PHP doesn’t natively support PDF generation, there are several libraries that make this task straightforward.
In this post, we’ll explore how to create a PHP HTML PDF generator. We’ll also address whether it’s possible to do this without a library, discuss popular library options, and provide a full example of generating a PDF from HTML content.
Can You Generate PDFs in PHP Without a Library?
Technically, it is not possible to generate a PDF from HTML in PHP without relying on some sort of library or external tool. PDF is a complex file format that requires a lot of overhead for rendering fonts, layout, and images correctly. PHP doesn’t have built-in support for working with PDF files, so using a library is necessary for this task.
Luckily, there are excellent libraries available for generating PDFs in PHP, making this process much easier.
Popular PHP Libraries for HTML to PDF Conversion
Here are some popular libraries that you can use to generate a PDF from HTML content in PHP:
1. DOMPDF
DOMPDF is one of the most popular open-source PHP libraries for converting HTML and CSS into PDFs. It supports most HTML5 tags and basic CSS properties, making it a great choice for generating PDFs with custom styling.
Key Features:
- Easy to use and integrate with PHP.
- Supports most common HTML and CSS features.
- Allows the embedding of images and fonts.
2. TCPDF
TCPDF is a powerful library that allows for generating PDFs directly from PHP code. While it does not natively convert HTML to PDF as smoothly as DOMPDF, it offers flexibility and support for a wide range of PDF functionalities, including bookmarks, barcodes, and digital signatures.
Key Features:
- No external dependencies.
- Supports complex elements like barcodes, QR codes, and graphics.
- Customizable headers and footers.
3. MPDF
MPDF is similar to DOMPDF but supports more CSS properties, and it’s faster for generating large PDFs. It converts HTML to PDF, supporting UTF-8 and a wide range of fonts and languages.
Key Features:
- Supports most CSS properties.
- Handles large documents efficiently.
- Offers built-in support for right-to-left languages (e.g., Arabic, Hebrew).
4. WKHTMLTOPDF
WKHTMLTOPDF is a command-line tool that converts HTML pages into PDFs using the WebKit rendering engine. While this is not a pure PHP library, it can be easily integrated with PHP via shell commands or packages like KnpSnappy.
Key Features:
- Provides excellent HTML-to-PDF conversion accuracy.
- Supports JavaScript and CSS3.
- Allows you to create PDFs from URLs or raw HTML.
Full Example: Creating a PDF from HTML Content Using DOMPDF
Now, let’s walk through an example of how to generate a PDF from HTML content using DOMPDF, one of the easiest libraries to work with.
Step 1: Install DOMPDF
First, you need to install the DOMPDF library. If you’re using Composer, the following command will install it for you:
composer require dompdf/dompdf
If you don’t use Composer, you can download the DOMPDF package manually from DOMPDF GitHub and include it in your project.
Step 2: Create a Basic HTML Template
Create an HTML template that you want to convert into a PDF. Here’s a simple example:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>PDF Example</title>
<style>
body { font-family: Arial, sans-serif; }
h1 { color: #4CAF50; }
p { font-size: 14px; }
table { width: 100%; border-collapse: collapse; }
table, th, td { border: 1px solid black; padding: 8px; text-align: left; }
</style>
</head>
<body>
<h1>Invoice</h1>
<p>Thank you for your purchase! Below are the details of your order:</p>
<table>
<thead>
<tr>
<th>Item</th>
<th>Price</th>
</tr>
</thead>
<tbody>
<tr>
<td>Product 1</td>
<td>$50</td>
</tr>
<tr>
<td>Product 2</td>
<td>$30</td>
</tr>
</tbody>
</table>
<p>Total: $80</p>
</body>
</html>
Step 3: Convert HTML to PDF Using DOMPDF
Now that we have our HTML, we can write a PHP script to convert it to a PDF.
<?php
require 'vendor/autoload.php'; // Include the autoloader if you're using Composer
use Dompdf\Dompdf;
use Dompdf\Options;
// Configure Dompdf options
$options = new Options();
$options->set('defaultFont', 'Courier');
$dompdf = new Dompdf($options);
// Load the HTML content
$html = file_get_contents('invoice.html'); // Assuming the HTML file is saved as 'invoice.html'
$dompdf->loadHtml($html);
// Set the paper size and orientation
$dompdf->setPaper('A4', 'portrait');
// Render the HTML as PDF
$dompdf->render();
// Output the generated PDF (either in the browser or save it as a file)
$dompdf->stream("invoice.pdf", ["Attachment" => 0]); // Set 'Attachment' to 1 to download the PDF instead of displaying it.
Step 4: Running the PHP Script
Now, when you run this script in your browser or from the command line, it will generate the PDF from the provided HTML. If you set the Attachment parameter to 0, the PDF will display in the browser. If set to 1, the browser will download the PDF file.
Tips for Working with HTML and PDF Generation
1. Styling and Fonts
When converting HTML to PDF, be mindful of the CSS styles you use. Some libraries, like DOMPDF, have limited support for certain CSS properties, especially newer ones like flexbox or grid. Stick to simple and widely supported CSS for best results.
2. Images and Assets
If your HTML contains images or external assets (e.g., CSS files), make sure the paths to these assets are correct. For example, use absolute paths or base64-encoded images to ensure they appear correctly in the generated PDF.
3. Performance
Generating PDFs can be resource-intensive, especially if the HTML is complex or the document is large. If you are generating large volumes of PDFs or have performance issues, consider caching the generated PDFs or offloading the task to a background process.
Conclusion
Generating PDFs from HTML using PHP is a practical way to deliver downloadable documents to your users, whether it’s invoices, reports, or certificates. While PHP doesn’t have built-in support for PDF generation, libraries like DOMPDF, MPDF, TCPDF, and WKHTMLTOPDF make it easy to convert HTML into PDF files.
In this post, we walked through the steps of generating a PDF using the DOMPDF library. With a few lines of code, you can generate professional-looking PDFs from dynamic HTML content. Depending on your project’s needs, you can explore other libraries or adjust your approach to fit your specific requirements.