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The LAMP stack, consisting of Linux, Apache, MySQL, and PHP, is one of the most popular platforms for web development. For web developers, the ability to convert XHTML to PDF within this environment is a common need. PDF, as a widely used document format, is frequently used for file sharing and archiving. However, converting XHTML documents to PDF in a LAMP environment presents some challenges, which we will explore in this article.
XHTML (Extensible Hypertext Markup Language) is a stricter version of HTML, based on XML. Compared to HTML, XHTML requires more rigorous syntax, ensuring better compatibility across different browsers. The main advantage of XHTML lies in its structured nature, reducing parsing errors across various browsers.
In a LAMP environment, several PHP libraries can be used to convert XHTML to PDF. Below, we will discuss some of the most commonly used libraries and their implementation methods.
DOMPDF is an open-source PHP library specifically designed for converting HTML and XHTML documents to PDF. It supports CSS for formatting, ensuring that the PDF document looks the same as the original HTML/XHTML. DOMPDF is easy to deploy in LAMP environments and works well for most web development projects.
<?php
require_once 'dompdf/autoload.inc.php';
use Dompdf\Dompdf;
$dompdf = new Dompdf();
$html = file_get_contents('test.html');
$dompdf->loadHtml($html);
$dompdf->setPaper('A4', 'landscape');
$dompdf->render();
$dompdf->stream("test.pdf", array("Attachment" => false));
?>
The above code demonstrates how to use the DOMPDF library to convert an XHTML document into a PDF. First, we load the XHTML document using `file_get_contents()`, set the page size to A4, and render the PDF, which is then streamed to the browser.
TCPDF is another powerful PHP library for generating PDF documents from HTML and XHTML. It supports multiple languages and character sets, making it suitable for internationalization. TCPDF is highly flexible and provides advanced features like encryption, compression, and detailed PDF customization.
<?php
require_once('tcpdf/tcpdf.php');
$html = file_get_contents('test.html');
$pdf = new TCPDF();
$pdf->SetCreator(PDF_CREATOR);
$pdf->SetAuthor('Author Name');
$pdf->SetTitle('Title');
$pdf->SetSubject('Subject');
$pdf->setFontSubsetting(true);
$pdf->AddPage();
$pdf->writeHTML($html, true, false, true, false, '');
$pdf->Output('test.pdf', 'I');
?>
With TCPDF, you can set various metadata like creator, author, title, and subject for the PDF. The `writeHTML()` function converts the HTML or XHTML into a PDF, which is then output to the browser.
FPDF is a lightweight PHP library that allows developers to create PDF documents from scratch. Unlike DOMPDF and TCPDF, FPDF does not directly support HTML or XHTML parsing. However, it offers a powerful set of functions to create PDFs, including font, color, image, and page management.
<?php
require('fpdf/fpdf.php');
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial', 'B', 16);
$pdf->Cell(40, 10, 'Hello World!');
$pdf->Output();
?>
The above example shows how FPDF works by manually setting the font, adding a page, and creating a cell with the text "Hello World!". Finally, the PDF is output to the browser.
wkhtmltopdf is an open-source command-line tool that converts HTML and XHTML documents to PDF. Based on the WebKit rendering engine, which is used by browsers like Google Chrome and Safari, it supports complex CSS, JavaScript, and images.
wkhtmltopdf test.html test.pdf
This simple command converts an XHTML document into a PDF. It’s perfect for server-side use or batch processing tasks.
mPDF is a powerful PHP library for converting HTML and XHTML to PDF. It supports Unicode characters, multi-language documents, and complex layouts. mPDF is easy to use and deploy in LAMP environments, making it ideal for internationalized projects.
<?php
require_once __DIR__ . '/vendor/autoload.php';
$mpdf = new \Mpdf\Mpdf();
$html = file_get_contents('test.html');
$mpdf->WriteHTML($html);
$mpdf->Output();
?>
With mPDF, we load the HTML or XHTML content, convert it into a PDF, and output the document to the browser using the `WriteHTML()` method.
Although converting XHTML to PDF in a LAMP environment can seem challenging, there are several powerful libraries available to simplify the process. DOMPDF, TCPDF, FPDF, and mPDF are commonly used PHP libraries for this task. Each library offers unique features and capabilities, and choosing the right one depends on the specific requirements of the project. By leveraging these libraries, web developers can easily convert XHTML documents to PDF and share them online.
