CssPurger

CssPurger is a lightweight PHP library to remove unused CSS rules from large stylesheets. It’s perfect for optimizing CSS frameworks like Bootstrap based on actual usage in your project.

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🧩 Installation

Install via Composer:

composer require jbsnewmedia/css-purger

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🚀 Features

• Removes unused CSS based on custom-defined selectors
• Supports nested blocks (e.g. @media)
• Fully supports selectors with pseudo-classes like :hover, :focus, etc.
• Output as minified or pretty-printed CSS
• Easily extendable via subclassing
• No external dependencies
• Bootstrap integration example included

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🔧 Usage

use JBSNewMedia\CssPurger\Vendors\Bootstrap;

$purger = new Bootstrap('./assets/css/bootstrap.css');

$purger->loadContent();
$purger->prepareContent();
$purger->runContent();

// Add the selectors you want to keep
$purger->addSelectors([
    ':root',
    '[data-bs-theme=light]',
    '[data-bs-theme=dark]',
    'body',
    'h1',
    '.h1',
    '.container',
    '.pt-3',
    '.pb-3',
    '.alert',
    '.alert-danger',
    '.btn:hover',
]);

// Save the result
file_put_contents('./assets/css/bootstrap-purged.css', $purger->generateOutput(false)); // readable
file_put_contents('./assets/css/bootstrap-purged.min.css', $purger->generateOutput());   // minified

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🧠 Extendability

You can subclass CssPurger to customize parsing or handling, e.g. for Bootstrap-specific structures:

use JBSNewMedia\CssPurger\CssPurger;

class CssPurgerBootstrap extends CssPurger
{
    public function prepareContent(): self
    {
        $this->cssBlockPrefix = substr($this->content, 0, strpos($this->content, ':root'));
        $this->content = str_replace("*/\n:root,", "*/\n}\n:root,", $this->content);
        return $this;
    }
}

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⚠️ Notes

• This is not a full CSS parser — it uses lightweight string-based logic for performance
• You must explicitly define which selectors to keep

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📄 License

MIT License — free for personal and commercial use.

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🤝 Contributing

Pull requests, bug reports and ideas for improvements are always welcome!

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🧑‍💻 Author

Maintained by JBS New Media.