$book = fluidxml();

$book->add('title', 'The Theory Of Everything')
     ->add('author', 'S. Hawking')
     ->add('chapters', true)
         ->add('chapter', 'Ideas About The Universe', ['id' => 1])
         ->add('chapter', 'The Expanding Universe',   ['id' => 2]);

$book = new FluidXml();

$book->addChild('title', 'The Theory Of Everything')
     ->addChild('author', 'S. Hawking')
     ->addChild('chapters', true)
         ->addChild('chapter', 'Ideas About The Universe', ['id' => 1])
         ->addChild('chapter', 'The Expanding Universe',   ['id' => 2]);

$book->add([ 'title'  => 'The Theory Of Everything',
             'author' => 'S. Hawking',
             'chapters' => [
                    [ 'chapter' => [
                            '@id' => '1',
                            '@'   => 'Ideas About The Universe' ] ],
                    [ 'chapter' => [
                            '@id' => '2',
                            '@'   => 'The Expanding Universe' ] ],
           ]]);

echo $book;

$book->query('//title', '//author', '//chapter')
        ->attr('lang', 'en');

$book->query('title', 'author', 'chapters > chapter')
        ->attr('lang', 'en');

$book->namespace('xhtml', 'http://www.w3.org/1999/xhtml')
     ->add('xhtml:h1')
     ->query('//xhtml:h1')  // XPath namespace.
     ->query('xhtml|h1');   // CSS namespace.

$book->add(<<<XML
    <cover class="front">
        <img src="http://goo.gl/kO3Iov"/>
    </cover>
    <cover class="back">
        <img src="http://goo.gl/kO3Iov"/>
    </cover>
XML
);

$book->query('//chapter')
        ->each(function($i) {
             $this->attr('id', $i);
        });

$book->query('//chapters')
        ->times(3)
            ->add('chapter')
        ->times(4, function($i) {
            $this->add('chapter');
            $this->add('illustration');
        });

$book->query('//chapters')
        ->filter(function($i, $node) {
            return $i % 2 === 0;
        })
        ->attr('even');

fluidxml($domdocument)
    ->query('/html/body')
         ->add($simplexml);

// Yes, we merged a DOMDocument with a SimpleXMLElement
// and everything is still fluid.

use function \FluidXml\fluidxml;
use function \FluidXml\fluidns;
use function \FluidXml\fluidify;

use \FluidXml\FluidXml;
use \FluidXml\FluidNamespace;