Add element registry

composer.json

@@ -1,7 +1,7 @@
 {
  "name": "simplesamlphp/xml-common",
  "description": "A library with classes and utilities for handling XML structures.",
- "type": "project",
+ "type": "simplesamlphp-xmlprovider",
  "keywords": ["saml", "xml"],
  "homepage": "http://simplesamlphp.org",
  "license": "LGPL-2.1-or-later",
@@ -34,7 +34,8 @@
  "ext-spl": "*",
  "ext-xmlreader": "*",
 
- "simplesamlphp/assert": "^1.2"
+ "simplesamlphp/assert": "^1.2",
+ "symfony/finder": "^6.4"
  },
  "require-dev": {
  "simplesamlphp/simplesamlphp-test-framework": "^1.7"
@@ -47,7 +48,8 @@
  "allow-plugins": {
  "composer/package-versions-deprecated": true,
  "dealerdirect/phpcodesniffer-composer-installer": true,
- "phpstan/extension-installer": true
+ "phpstan/extension-installer": true,
+ "simplesamlphp/composer-xmlprovider-installer": true
  }
  }
 }

src/Registry/AbstractElementRegistry.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\XML\Registry;
+
+use SimpleSAML\Assert\Assert;
+use SimpleSAML\XML\AbstractElement;
+use SimpleSAML\XML\Exception\InvalidDOMElementException;
+use Symfony\Component\Finder\Finder;
+
+use function array_key_exists;
+use function array_merge;
+use function dirname;
+use function implode;
+
+abstract class AbstractElementRegistry
+{
+ /** @var \SimpleSAML\XML\Registry\AbstractElementRegistry|null $instance */
+ protected static ?AbstractElementRegistry $instance = null;
+
+
+ /** @var array<string, string> */
+ protected array $registry = [];
+
+ final private function __construct()
+ {
+ // Initialize the registry with all the elements we know
+ $classesDir = dirname(__FILE__, 3) . '/vendor/simplesamlphp/composer-xmlprovider-installer/classes';
+
+ $finder = Finder::create()->files()->name('element.registry.*.php')->in($classesDir);
+ if ($finder->hasResults()) {
+ foreach ($finder as $file) {
+ $elements = include($file);
+ $this->registry = array_merge($this->registry, $elements);
+ }
+ }
+ }
+
+
+ public static function getInstance(): AbstractElementRegistry
+ {
+ if (self::$instance === null) {
+ self::$instance = new static();
+ }
+
+ return self::$instance;
+ }
+
+
+ /**
+ * Register a class that can process a certain XML-element.
+ *
+ * @param string $class The class name of a class extending AbstractElement.
+ */
+ public function registerElementHandler(string $class): void
+ {
+ Assert::subclassOf($class, AbstractElement::class);
+ $className = AbstractElement::getClassName($class);
+ $key = ($class::NS === null) ? $className : implode(':', [$class::NS, $className]);
+ $this->registry[$key] = $class;
+ }
+
+
+ /**
+ * Search for a class that implements an $element in the given $namespace.
+ *
+ * Such classes must have been registered previously by calling registerElementHandler(), and they must
+ * extend \SimpleSAML\XML\AbstractElement.
+ *
+ * @param string|null $namespace The namespace URI for the given element.
+ * @param string $element The local name of the element.
+ *
+ * @return string|null The fully-qualified name of a class extending \SimpleSAML\XML\AbstractElement and
+ * implementing support for the given element, or null if no such class has been registered before.
+ */
+ public function getElementHandler(?string $namespace, string $element): ?string
+ {
+ Assert::nullOrValidURI($namespace, InvalidDOMElementException::class);
+ Assert::validNCName($element, InvalidDOMElementException::class);
+
+ $key = ($namespace === null) ? $element : implode(':', [$namespace, $element]);
+ if (array_key_exists($key, $this->registry) === true) {
+ return $this->registry[$key];
+ }
+
+ return null;
+ }
+}