Effortlessly Generate PDFs from HTML Using PHP: A Comprehensive Guide

Creating PDFs from HTML using PHP is a common requirement for many web applications. Whether you need to generate invoices, reports, or any other type of document, PHP provides several tools and libraries to accomplish this task efficiently. This comprehensive guide will walk you through the process of generating PDFs from HTML using PHP, covering various approaches, best practices, and troubleshooting tips. Let's dive in!

Why Generate PDFs from HTML with PHP?

Generating PDFs from HTML offers numerous benefits. It allows you to create visually appealing documents with precise formatting, regardless of the user's operating system or browser. PDFs are also ideal for archiving and sharing documents, as they maintain a consistent appearance across different devices. Furthermore, generating PDFs on the server-side with PHP ensures that sensitive data remains secure and isn't exposed to the client-side.

Choosing the Right PDF Library for PHP

Several PHP libraries can help you generate PDFs from HTML. Each library has its strengths and weaknesses, so it's essential to choose the one that best suits your project's needs. Here are some popular options:

TCPDF: TCPDF is a widely used open-source library that supports a wide range of features, including Unicode, various image formats, and encryption. It's known for its flexibility and extensive documentation.
mPDF: mPDF is another popular choice that excels at converting HTML to PDF. It supports CSS styling, various fonts, and complex layouts. mPDF is particularly well-suited for generating PDFs with rich formatting.
Dompdf: Dompdf is a CSS 2.1 compliant HTML to PDF converter. It supports a wide range of HTML elements and CSS properties, making it easy to generate PDFs that closely resemble your HTML designs. However, it might be slower than other libraries for complex layouts.
wkhtmltopdf: While not a PHP library, wkhtmltopdf is a command-line tool that you can use with PHP to convert HTML to PDF. It relies on the WebKit rendering engine, providing excellent support for modern HTML and CSS features. It can be invoked from PHP using the exec() function.

For this guide, we'll primarily focus on using mPDF due to its robust HTML/CSS support and ease of use.

Setting Up mPDF for PDF Generation

First, you need to install mPDF using Composer. If you don't have Composer installed, you can download it from getcomposer.org. Once you have Composer, navigate to your project directory in the terminal and run the following command:

composer require mpdf/mpdf

This command will download and install mPDF and its dependencies in your project. After the installation is complete, you can include the autoloader in your PHP script to use mPDF:

<?php
require_once __DIR__ . '/vendor/autoload.php';

// Now you can use mPDF

?>

Basic Example: Generating a Simple PDF from HTML

Let's start with a simple example to generate a basic PDF from HTML using mPDF:

<?php
require_once __DIR__ . '/vendor/autoload.php';

$mpdf = new     Mpdf\Mpdf();
$html = '<!DOCTYPE html>
<html>
<head>
<title>Simple PDF Example</title>
</head>
<body>
<h1>Hello, World!</h1>
<p>This is a simple PDF generated from HTML using PHP and mPDF.</p>
</body>
</html>';

$mpdf->WriteHTML($html);
$mpdf->Output('simple.pdf', 'I');

?>

In this example:

We include the autoloader to load the mPDF library.
We create a new Mpdf object.
We define the HTML content that we want to convert to PDF.
We use the WriteHTML() method to add the HTML content to the PDF.
We use the Output() method to generate the PDF and send it to the browser. The 'I' parameter tells the browser to display the PDF inline.

Save this code as generate_pdf.php and run it in your browser. You should see a PDF document containing the "Hello, World!" message.

Advanced Styling: Using CSS for PDF Formatting

One of the significant advantages of using mPDF is its support for CSS styling. You can embed CSS styles directly into your HTML or link to an external stylesheet to format your PDF documents. Here's an example of using CSS to style the PDF:

<?php
require_once __DIR__ . '/vendor/autoload.php';

$mpdf = new \Mpdf\Mpdf();
$html = '<!DOCTYPE html>
<html>
<head>
<title>Styled PDF Example</title>
<style>
body {
 font-family: Arial, sans-serif;
}
h1 {
 color: navy;
 text-align: center;
}
p {
 font-size: 16px;
 line-height: 1.5;
}
</style>
</head>
<body>
<h1>Styled PDF Example</h1>
<p>This is a styled PDF generated from HTML using PHP and mPDF. We are using CSS to format the content.</p>
</body>
</html>';

$mpdf->WriteHTML($html);
$mpdf->Output('styled.pdf', 'I');

?>

In this example, we've added CSS styles to the <head> section of the HTML document. These styles will be applied to the PDF, allowing you to control the appearance of your document.

Working with Images in PDF Documents

Adding images to your PDF documents is straightforward with mPDF. You can use the standard HTML <img> tag to embed images in your PDF. Make sure the image paths are correct and accessible to the PHP script. Here's an example:

```php <?php require_once DIR . '/vendor/autoload.php';

$mpdf = new \Mpdf\Mpdf(); $html = ' PDF with Image

<img src=