erusev/parsedown

Parsedown is a popular, open-source PHP library designed for converting Markdown text into HTML. Developed by Erusev, it stands out for its speed, reliability, and security, making it a go-to choice for developers needing to process user-generated content or render static Markdown files within their PHP applications.

Key Features:
* Speed: Parsedown is renowned for being one of the fastest Markdown parsers available in PHP, achieving high performance even with large inputs.
* Accuracy and Compliance: It aims for high compliance with the original Markdown specification. Its extended version, Parsedown Extra, adds support for more advanced features like GitHub Flavored Markdown (GFM) tables, footnotes, and definition lists.
* Security: By default, Parsedown sanitizes potentially malicious HTML elements (like script tags) within the Markdown input, helping to prevent Cross-Site Scripting (XSS) vulnerabilities when displaying user-submitted content.
* Lightweight and Easy to Use: It has a small footprint and a very straightforward API, making integration into existing projects simple.
* Extensible: While powerful out-of-the-box, it also allows for custom extensions to its parsing rules if specific behaviors are required.

How it Works:
At its core, Parsedown takes a string of Markdown text as input and processes it through a series of parsing rules to convert it into its equivalent HTML representation. This transformation handles common Markdown elements such as headers, paragraphs, lists, links, images, code blocks, emphasis (bold/italic), and more.

Use Cases:
* Blog/CMS Systems: Converting post content written in Markdown into displayable HTML.
* Documentation Sites: Rendering Markdown documentation files dynamically.
* User-Generated Content: Safely converting user comments or forum posts from Markdown to HTML.
* Static Site Generators: As a component for processing Markdown files.

Installation is typically done via Composer: `composer require erusev/parsedown`.

<?php

require_once 'vendor/autoload.php'; // Autoload files using Composer

// 1. Basic Usage: Create a Parsedown instance
$parsedown = new Parsedown();

// 2. Define some Markdown content
$markdownContent = "# Welcome to Parsedown!

This is a simple example of Markdown.

- Item One
- Item Two
- Item Three

You can also include [links](https://parsedown.org) and `inline code`.

```php
// Code blocks are also supported
echo \"Hello, Parsedown!\";
```

 Another Header
A paragraph with *emphasis*.
";

// 3. Convert Markdown to HTML
$htmlOutput = $parsedown->text($markdownContent);

// 4. Display the HTML output
echo "<h1>Original Markdown:</h1>";
echo "<pre>" . htmlspecialchars($markdownContent) . "</pre>"; // Display raw Markdown for comparison

echo "<h1>Converted HTML:</h1>";
echo $htmlOutput;

// --- Optional: Example with Parsedown Extra (requires separate installation) ---
// To use Parsedown Extra, you would first install it via Composer:
// composer require erusev/parsedown-extra
//
// require_once 'vendor/autoload.php';
// $parsedownExtra = new ParsedownExtra();
// $extraMarkdown = "Table Example:
// 
// | Header 1 | Header 2 |
// | -------- | -------- |
// | Cell 1   | Cell 2   |
// | Cell 3   | Cell 4   |";
//
// echo "<h2>Parsedown Extra Example:</h2>";
// echo $parsedownExtra->text($extraMarkdown);

?>