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    <h3>Editing: XmlFileLoader.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Routing\Loader;

use Symfony\Component\Config\Loader\FileLoader;
use Symfony\Component\Config\Resource\FileResource;
use Symfony\Component\Config\Util\XmlUtils;
use Symfony\Component\Routing\Loader\Configurator\Traits\HostTrait;
use Symfony\Component\Routing\Loader\Configurator\Traits\LocalizedRouteTrait;
use Symfony\Component\Routing\Loader\Configurator\Traits\PrefixTrait;
use Symfony\Component\Routing\RouteCollection;

/**
 * XmlFileLoader loads XML routing files.
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 * @author Tobias Schultze &lt;http://tobion.de&gt;
 */
class XmlFileLoader extends FileLoader
{
    use HostTrait;
    use LocalizedRouteTrait;
    use PrefixTrait;

    public const NAMESPACE_URI = 'http://symfony.com/schema/routing';
    public const SCHEME_PATH = '/schema/routing/routing-1.0.xsd';

    /**
     * @throws \InvalidArgumentException when the file cannot be loaded or when the XML cannot be
     *                                   parsed because it does not validate against the scheme
     */
    public function load(mixed $file, string $type = null): RouteCollection
    {
        $path = $this-&gt;locator-&gt;locate($file);

        $xml = $this-&gt;loadFile($path);

        $collection = new RouteCollection();
        $collection-&gt;addResource(new FileResource($path));

        // process routes and imports
        foreach ($xml-&gt;documentElement-&gt;childNodes as $node) {
            if (!$node instanceof \DOMElement) {
                continue;
            }

            $this-&gt;parseNode($collection, $node, $path, $file);
        }

        return $collection;
    }

    /**
     * Parses a node from a loaded XML file.
     *
     * @throws \InvalidArgumentException When the XML is invalid
     */
    protected function parseNode(RouteCollection $collection, \DOMElement $node, string $path, string $file)
    {
        if (self::NAMESPACE_URI !== $node-&gt;namespaceURI) {
            return;
        }

        switch ($node-&gt;localName) {
            case 'route':
                $this-&gt;parseRoute($collection, $node, $path);
                break;
            case 'import':
                $this-&gt;parseImport($collection, $node, $path, $file);
                break;
            case 'when':
                if (!$this-&gt;env || $node-&gt;getAttribute('env') !== $this-&gt;env) {
                    break;
                }
                foreach ($node-&gt;childNodes as $node) {
                    if ($node instanceof \DOMElement) {
                        $this-&gt;parseNode($collection, $node, $path, $file);
                    }
                }
                break;
            default:
                throw new \InvalidArgumentException(sprintf('Unknown tag &quot;%s&quot; used in file &quot;%s&quot;. Expected &quot;route&quot; or &quot;import&quot;.', $node-&gt;localName, $path));
        }
    }

    public function supports(mixed $resource, string $type = null): bool
    {
        return \is_string($resource) &amp;&amp; 'xml' === pathinfo($resource, \PATHINFO_EXTENSION) &amp;&amp; (!$type || 'xml' === $type);
    }

    /**
     * Parses a route and adds it to the RouteCollection.
     *
     * @throws \InvalidArgumentException When the XML is invalid
     */
    protected function parseRoute(RouteCollection $collection, \DOMElement $node, string $path)
    {
        if ('' === $id = $node-&gt;getAttribute('id')) {
            throw new \InvalidArgumentException(sprintf('The &lt;route&gt; element in file &quot;%s&quot; must have an &quot;id&quot; attribute.', $path));
        }

        if ('' !== $alias = $node-&gt;getAttribute('alias')) {
            $alias = $collection-&gt;addAlias($id, $alias);

            if ($deprecationInfo = $this-&gt;parseDeprecation($node, $path)) {
                $alias-&gt;setDeprecated($deprecationInfo['package'], $deprecationInfo['version'], $deprecationInfo['message']);
            }

            return;
        }

        $schemes = preg_split('/[\s,\|]++/', $node-&gt;getAttribute('schemes'), -1, \PREG_SPLIT_NO_EMPTY);
        $methods = preg_split('/[\s,\|]++/', $node-&gt;getAttribute('methods'), -1, \PREG_SPLIT_NO_EMPTY);

        [$defaults, $requirements, $options, $condition, $paths, /* $prefixes */, $hosts] = $this-&gt;parseConfigs($node, $path);

        if (!$paths &amp;&amp; '' === $node-&gt;getAttribute('path')) {
            throw new \InvalidArgumentException(sprintf('The &lt;route&gt; element in file &quot;%s&quot; must have a &quot;path&quot; attribute or &lt;path&gt; child nodes.', $path));
        }

        if ($paths &amp;&amp; '' !== $node-&gt;getAttribute('path')) {
            throw new \InvalidArgumentException(sprintf('The &lt;route&gt; element in file &quot;%s&quot; must not have both a &quot;path&quot; attribute and &lt;path&gt; child nodes.', $path));
        }

        $routes = $this-&gt;createLocalizedRoute($collection, $id, $paths ?: $node-&gt;getAttribute('path'));
        $routes-&gt;addDefaults($defaults);
        $routes-&gt;addRequirements($requirements);
        $routes-&gt;addOptions($options);
        $routes-&gt;setSchemes($schemes);
        $routes-&gt;setMethods($methods);
        $routes-&gt;setCondition($condition);

        if (null !== $hosts) {
            $this-&gt;addHost($routes, $hosts);
        }
    }

    /**
     * Parses an import and adds the routes in the resource to the RouteCollection.
     *
     * @throws \InvalidArgumentException When the XML is invalid
     */
    protected function parseImport(RouteCollection $collection, \DOMElement $node, string $path, string $file)
    {
        /** @var \DOMElement $resourceElement */
        if (!($resource = $node-&gt;getAttribute('resource') ?: null) &amp;&amp; $resourceElement = $node-&gt;getElementsByTagName('resource')[0] ?? null) {
            $resource = [];
            /** @var \DOMAttr $attribute */
            foreach ($resourceElement-&gt;attributes as $attribute) {
                $resource[$attribute-&gt;name] = $attribute-&gt;value;
            }
        }

        if (!$resource) {
            throw new \InvalidArgumentException(sprintf('The &lt;import&gt; element in file &quot;%s&quot; must have a &quot;resource&quot; attribute or element.', $path));
        }

        $type = $node-&gt;getAttribute('type');
        $prefix = $node-&gt;getAttribute('prefix');
        $schemes = $node-&gt;hasAttribute('schemes') ? preg_split('/[\s,\|]++/', $node-&gt;getAttribute('schemes'), -1, \PREG_SPLIT_NO_EMPTY) : null;
        $methods = $node-&gt;hasAttribute('methods') ? preg_split('/[\s,\|]++/', $node-&gt;getAttribute('methods'), -1, \PREG_SPLIT_NO_EMPTY) : null;
        $trailingSlashOnRoot = $node-&gt;hasAttribute('trailing-slash-on-root') ? XmlUtils::phpize($node-&gt;getAttribute('trailing-slash-on-root')) : true;
        $namePrefix = $node-&gt;getAttribute('name-prefix') ?: null;

        [$defaults, $requirements, $options, $condition, /* $paths */, $prefixes, $hosts] = $this-&gt;parseConfigs($node, $path);

        if ('' !== $prefix &amp;&amp; $prefixes) {
            throw new \InvalidArgumentException(sprintf('The &lt;route&gt; element in file &quot;%s&quot; must not have both a &quot;prefix&quot; attribute and &lt;prefix&gt; child nodes.', $path));
        }

        $exclude = [];
        foreach ($node-&gt;childNodes as $child) {
            if ($child instanceof \DOMElement &amp;&amp; $child-&gt;localName === $exclude &amp;&amp; self::NAMESPACE_URI === $child-&gt;namespaceURI) {
                $exclude[] = $child-&gt;nodeValue;
            }
        }

        if ($node-&gt;hasAttribute('exclude')) {
            if ($exclude) {
                throw new \InvalidArgumentException('You cannot use both the attribute &quot;exclude&quot; and &lt;exclude&gt; tags at the same time.');
            }
            $exclude = [$node-&gt;getAttribute('exclude')];
        }

        $this-&gt;setCurrentDir(\dirname($path));

        /** @var RouteCollection[] $imported */
        $imported = $this-&gt;import($resource, '' !== $type ? $type : null, false, $file, $exclude) ?: [];

        if (!\is_array($imported)) {
            $imported = [$imported];
        }

        foreach ($imported as $subCollection) {
            $this-&gt;addPrefix($subCollection, $prefixes ?: $prefix, $trailingSlashOnRoot);

            if (null !== $hosts) {
                $this-&gt;addHost($subCollection, $hosts);
            }

            if (null !== $condition) {
                $subCollection-&gt;setCondition($condition);
            }
            if (null !== $schemes) {
                $subCollection-&gt;setSchemes($schemes);
            }
            if (null !== $methods) {
                $subCollection-&gt;setMethods($methods);
            }
            if (null !== $namePrefix) {
                $subCollection-&gt;addNamePrefix($namePrefix);
            }
            $subCollection-&gt;addDefaults($defaults);
            $subCollection-&gt;addRequirements($requirements);
            $subCollection-&gt;addOptions($options);

            $collection-&gt;addCollection($subCollection);
        }
    }

    /**
     * @throws \InvalidArgumentException When loading of XML file fails because of syntax errors
     *                                   or when the XML structure is not as expected by the scheme -
     *                                   see validate()
     */
    protected function loadFile(string $file): \DOMDocument
    {
        return XmlUtils::loadFile($file, __DIR__.static::SCHEME_PATH);
    }

    /**
     * Parses the config elements (default, requirement, option).
     *
     * @throws \InvalidArgumentException When the XML is invalid
     */
    private function parseConfigs(\DOMElement $node, string $path): array
    {
        $defaults = [];
        $requirements = [];
        $options = [];
        $condition = null;
        $prefixes = [];
        $paths = [];
        $hosts = [];

        /** @var \DOMElement $n */
        foreach ($node-&gt;getElementsByTagNameNS(self::NAMESPACE_URI, '*') as $n) {
            if ($node !== $n-&gt;parentNode) {
                continue;
            }

            switch ($n-&gt;localName) {
                case 'path':
                    $paths[$n-&gt;getAttribute('locale')] = trim($n-&gt;textContent);
                    break;
                case 'host':
                    $hosts[$n-&gt;getAttribute('locale')] = trim($n-&gt;textContent);
                    break;
                case 'prefix':
                    $prefixes[$n-&gt;getAttribute('locale')] = trim($n-&gt;textContent);
                    break;
                case 'default':
                    if ($this-&gt;isElementValueNull($n)) {
                        $defaults[$n-&gt;getAttribute('key')] = null;
                    } else {
                        $defaults[$n-&gt;getAttribute('key')] = $this-&gt;parseDefaultsConfig($n, $path);
                    }

                    break;
                case 'requirement':
                    $requirements[$n-&gt;getAttribute('key')] = trim($n-&gt;textContent);
                    break;
                case 'option':
                    $options[$n-&gt;getAttribute('key')] = XmlUtils::phpize(trim($n-&gt;textContent));
                    break;
                case 'condition':
                    $condition = trim($n-&gt;textContent);
                    break;
                case 'resource':
                    break;
                default:
                    throw new \InvalidArgumentException(sprintf('Unknown tag &quot;%s&quot; used in file &quot;%s&quot;. Expected &quot;default&quot;, &quot;requirement&quot;, &quot;option&quot; or &quot;condition&quot;.', $n-&gt;localName, $path));
            }
        }

        if ($controller = $node-&gt;getAttribute('controller')) {
            if (isset($defaults['_controller'])) {
                $name = $node-&gt;hasAttribute('id') ? sprintf('&quot;%s&quot;.', $node-&gt;getAttribute('id')) : sprintf('the &quot;%s&quot; tag.', $node-&gt;tagName);

                throw new \InvalidArgumentException(sprintf('The routing file &quot;%s&quot; must not specify both the &quot;controller&quot; attribute and the defaults key &quot;_controller&quot; for ', $path).$name);
            }

            $defaults['_controller'] = $controller;
        }
        if ($node-&gt;hasAttribute('locale')) {
            $defaults['_locale'] = $node-&gt;getAttribute('locale');
        }
        if ($node-&gt;hasAttribute('format')) {
            $defaults['_format'] = $node-&gt;getAttribute('format');
        }
        if ($node-&gt;hasAttribute('utf8')) {
            $options['utf8'] = XmlUtils::phpize($node-&gt;getAttribute('utf8'));
        }
        if ($stateless = $node-&gt;getAttribute('stateless')) {
            if (isset($defaults['_stateless'])) {
                $name = $node-&gt;hasAttribute('id') ? sprintf('&quot;%s&quot;.', $node-&gt;getAttribute('id')) : sprintf('the &quot;%s&quot; tag.', $node-&gt;tagName);

                throw new \InvalidArgumentException(sprintf('The routing file &quot;%s&quot; must not specify both the &quot;stateless&quot; attribute and the defaults key &quot;_stateless&quot; for ', $path).$name);
            }

            $defaults['_stateless'] = XmlUtils::phpize($stateless);
        }

        if (!$hosts) {
            $hosts = $node-&gt;hasAttribute('host') ? $node-&gt;getAttribute('host') : null;
        }

        return [$defaults, $requirements, $options, $condition, $paths, $prefixes, $hosts];
    }

    /**
     * Parses the &quot;default&quot; elements.
     */
    private function parseDefaultsConfig(\DOMElement $element, string $path): array|bool|float|int|string|null
    {
        if ($this-&gt;isElementValueNull($element)) {
            return null;
        }

        // Check for existing element nodes in the default element. There can
        // only be a single element inside a default element. So this element
        // (if one was found) can safely be returned.
        foreach ($element-&gt;childNodes as $child) {
            if (!$child instanceof \DOMElement) {
                continue;
            }

            if (self::NAMESPACE_URI !== $child-&gt;namespaceURI) {
                continue;
            }

            return $this-&gt;parseDefaultNode($child, $path);
        }

        // If the default element doesn't contain a nested &quot;bool&quot;, &quot;int&quot;, &quot;float&quot;,
        // &quot;string&quot;, &quot;list&quot;, or &quot;map&quot; element, the element contents will be treated
        // as the string value of the associated default option.
        return trim($element-&gt;textContent);
    }

    /**
     * Recursively parses the value of a &quot;default&quot; element.
     *
     * @throws \InvalidArgumentException when the XML is invalid
     */
    private function parseDefaultNode(\DOMElement $node, string $path): array|bool|float|int|string|null
    {
        if ($this-&gt;isElementValueNull($node)) {
            return null;
        }

        switch ($node-&gt;localName) {
            case 'bool':
                return 'true' === trim($node-&gt;nodeValue) || '1' === trim($node-&gt;nodeValue);
            case 'int':
                return (int) trim($node-&gt;nodeValue);
            case 'float':
                return (float) trim($node-&gt;nodeValue);
            case 'string':
                return trim($node-&gt;nodeValue);
            case 'list':
                $list = [];

                foreach ($node-&gt;childNodes as $element) {
                    if (!$element instanceof \DOMElement) {
                        continue;
                    }

                    if (self::NAMESPACE_URI !== $element-&gt;namespaceURI) {
                        continue;
                    }

                    $list[] = $this-&gt;parseDefaultNode($element, $path);
                }

                return $list;
            case 'map':
                $map = [];

                foreach ($node-&gt;childNodes as $element) {
                    if (!$element instanceof \DOMElement) {
                        continue;
                    }

                    if (self::NAMESPACE_URI !== $element-&gt;namespaceURI) {
                        continue;
                    }

                    $map[$element-&gt;getAttribute('key')] = $this-&gt;parseDefaultNode($element, $path);
                }

                return $map;
            default:
                throw new \InvalidArgumentException(sprintf('Unknown tag &quot;%s&quot; used in file &quot;%s&quot;. Expected &quot;bool&quot;, &quot;int&quot;, &quot;float&quot;, &quot;string&quot;, &quot;list&quot;, or &quot;map&quot;.', $node-&gt;localName, $path));
        }
    }

    private function isElementValueNull(\DOMElement $element): bool
    {
        $namespaceUri = 'http://www.w3.org/2001/XMLSchema-instance';

        if (!$element-&gt;hasAttributeNS($namespaceUri, 'nil')) {
            return false;
        }

        return 'true' === $element-&gt;getAttributeNS($namespaceUri, 'nil') || '1' === $element-&gt;getAttributeNS($namespaceUri, 'nil');
    }

    /**
     * Parses the deprecation elements.
     *
     * @throws \InvalidArgumentException When the XML is invalid
     */
    private function parseDeprecation(\DOMElement $node, string $path): array
    {
        $deprecatedNode = null;
        foreach ($node-&gt;childNodes as $child) {
            if (!$child instanceof \DOMElement || self::NAMESPACE_URI !== $child-&gt;namespaceURI) {
                continue;
            }
            if ('deprecated' !== $child-&gt;localName) {
                throw new \InvalidArgumentException(sprintf('Invalid child element &quot;%s&quot; defined for alias &quot;%s&quot; in &quot;%s&quot;.', $child-&gt;localName, $node-&gt;getAttribute('id'), $path));
            }

            $deprecatedNode = $child;
        }

        if (null === $deprecatedNode) {
            return [];
        }

        if (!$deprecatedNode-&gt;hasAttribute('package')) {
            throw new \InvalidArgumentException(sprintf('The &lt;deprecated&gt; element in file &quot;%s&quot; must have a &quot;package&quot; attribute.', $path));
        }
        if (!$deprecatedNode-&gt;hasAttribute('version')) {
            throw new \InvalidArgumentException(sprintf('The &lt;deprecated&gt; element in file &quot;%s&quot; must have a &quot;version&quot; attribute.', $path));
        }

        return [
            'package' =&gt; $deprecatedNode-&gt;getAttribute('package'),
            'version' =&gt; $deprecatedNode-&gt;getAttribute('version'),
            'message' =&gt; trim($deprecatedNode-&gt;nodeValue),
        ];
    }
}
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