Important: each parameter in addition to the body variable for the `create` method must default to null, otherwise * > it violates the constraint with the interface; it is recommended to use the {@see Assert::notNull()} method to * > verify that a dependency is actually passed. * * This Factory also features a Service Locator component that is used to pass the right dependencies to the * `create` method of a tag; each dependency should be registered as a service or as a parameter. * * When you want to use a Tag of your own with custom handling you need to call the `registerTagHandler` method, pass * the name of the tag and a Fully Qualified Class Name pointing to a class that implements the Tag interface. */ final class StandardTagFactory implements TagFactory { /** PCRE regular expression matching a tag name. */ public const REGEX_TAGNAME = '[\w\-\_\\\\:]+'; /** * @var array> An array with a tag as a key, and an * FQCN to a class that handles it as an array value. */ private $tagHandlerMappings = [ 'author' => Author::class, 'covers' => Covers::class, 'deprecated' => Deprecated::class, // 'example' => '\phpDocumentor\Reflection\DocBlock\Tags\Example', 'link' => LinkTag::class, 'method' => Method::class, 'param' => Param::class, 'property-read' => PropertyRead::class, 'property' => Property::class, 'property-write' => PropertyWrite::class, 'return' => Return_::class, 'see' => SeeTag::class, 'since' => Since::class, 'source' => Source::class, 'throw' => Throws::class, 'throws' => Throws::class, 'uses' => Uses::class, 'var' => Var_::class, 'version' => Version::class, ]; /** * @var array> An array with a anotation s a key, and an * FQCN to a class that handles it as an array value. */ private $annotationMappings = []; /** * @var ReflectionParameter[][] a lazy-loading cache containing parameters * for each tagHandler that has been used. */ private $tagHandlerParameterCache = []; /** @var FqsenResolver */ private $fqsenResolver; /** * @var mixed[] an array representing a simple Service Locator where we can store parameters and * services that can be inserted into the Factory Methods of Tag Handlers. */ private $serviceLocator = []; /** * Initialize this tag factory with the means to resolve an FQSEN and optionally a list of tag handlers. * * If no tag handlers are provided than the default list in the {@see self::$tagHandlerMappings} property * is used. * * @see self::registerTagHandler() to add a new tag handler to the existing default list. * * @param array> $tagHandlers */ public function __construct(FqsenResolver $fqsenResolver, ?array $tagHandlers = null) { $this->fqsenResolver = $fqsenResolver; if ($tagHandlers !== null) { $this->tagHandlerMappings = $tagHandlers; } $this->addService($fqsenResolver, FqsenResolver::class); } public function create(string $tagLine, ?TypeContext $context = null) : Tag { if (!$context) { $context = new TypeContext(''); } [$tagName, $tagBody] = $this->extractTagParts($tagLine); return $this->createTag(trim($tagBody), $tagName, $context); } /** * @param mixed $value */ public function addParameter(string $name, $value) : void { $this->serviceLocator[$name] = $value; } public function addService(object $service, ?string $alias = null) : void { $this->serviceLocator[$alias ?: get_class($service)] = $service; } public function registerTagHandler(string $tagName, string $handler) : void { Assert::stringNotEmpty($tagName); Assert::classExists($handler); Assert::implementsInterface($handler, Tag::class); if (strpos($tagName, '\\') && $tagName[0] !== '\\') { throw new InvalidArgumentException( 'A namespaced tag must have a leading backslash as it must be fully qualified' ); } $this->tagHandlerMappings[$tagName] = $handler; } /** * Extracts all components for a tag. * * @return string[] */ private function extractTagParts(string $tagLine) : array { $matches = []; if (!preg_match('/^@(' . self::REGEX_TAGNAME . ')((?:[\s\(\{])\s*([^\s].*)|$)/us', $tagLine, $matches)) { throw new InvalidArgumentException( 'The tag "' . $tagLine . '" does not seem to be wellformed, please check it for errors' ); } if (count($matches) < 3) { $matches[] = ''; } return array_slice($matches, 1); } /** * Creates a new tag object with the given name and body or returns null if the tag name was recognized but the * body was invalid. */ private function createTag(string $body, string $name, TypeContext $context) : Tag { $handlerClassName = $this->findHandlerClassName($name, $context); $arguments = $this->getArgumentsForParametersFromWiring( $this->fetchParametersForHandlerFactoryMethod($handlerClassName), $this->getServiceLocatorWithDynamicParameters($context, $name, $body) ); try { $callable = [$handlerClassName, 'create']; Assert::isCallable($callable); /** @phpstan-var callable(string): ?Tag $callable */ $tag = call_user_func_array($callable, $arguments); return $tag ?? InvalidTag::create($body, $name); } catch (InvalidArgumentException $e) { return InvalidTag::create($body, $name)->withError($e); } } /** * Determines the Fully Qualified Class Name of the Factory or Tag (containing a Factory Method `create`). * * @return class-string */ private function findHandlerClassName(string $tagName, TypeContext $context) : string { $handlerClassName = Generic::class; if (isset($this->tagHandlerMappings[$tagName])) { $handlerClassName = $this->tagHandlerMappings[$tagName]; } elseif ($this->isAnnotation($tagName)) { // TODO: Annotation support is planned for a later stage and as such is disabled for now $tagName = (string) $this->fqsenResolver->resolve($tagName, $context); if (isset($this->annotationMappings[$tagName])) { $handlerClassName = $this->annotationMappings[$tagName]; } } return $handlerClassName; } /** * Retrieves the arguments that need to be passed to the Factory Method with the given Parameters. * * @param ReflectionParameter[] $parameters * @param mixed[] $locator * * @return mixed[] A series of values that can be passed to the Factory Method of the tag whose parameters * is provided with this method. */ private function getArgumentsForParametersFromWiring(array $parameters, array $locator) : array { $arguments = []; foreach ($parameters as $parameter) { $type = $parameter->getType(); $typeHint = null; if ($type instanceof ReflectionNamedType) { $typeHint = $type->getName(); if ($typeHint === 'self') { $declaringClass = $parameter->getDeclaringClass(); if ($declaringClass !== null) { $typeHint = $declaringClass->getName(); } } } if (isset($locator[$typeHint])) { $arguments[] = $locator[$typeHint]; continue; } $parameterName = $parameter->getName(); if (isset($locator[$parameterName])) { $arguments[] = $locator[$parameterName]; continue; } $arguments[] = null; } return $arguments; } /** * Retrieves a series of ReflectionParameter objects for the static 'create' method of the given * tag handler class name. * * @param class-string $handlerClassName * * @return ReflectionParameter[] */ private function fetchParametersForHandlerFactoryMethod(string $handlerClassName) : array { if (!isset($this->tagHandlerParameterCache[$handlerClassName])) { $methodReflection = new ReflectionMethod($handlerClassName, 'create'); $this->tagHandlerParameterCache[$handlerClassName] = $methodReflection->getParameters(); } return $this->tagHandlerParameterCache[$handlerClassName]; } /** * Returns a copy of this class' Service Locator with added dynamic parameters, * such as the tag's name, body and Context. * * @param TypeContext $context The Context (namespace and aliasses) that may be * passed and is used to resolve FQSENs. * @param string $tagName The name of the tag that may be * passed onto the factory method of the Tag class. * @param string $tagBody The body of the tag that may be * passed onto the factory method of the Tag class. * * @return mixed[] */ private function getServiceLocatorWithDynamicParameters( TypeContext $context, string $tagName, string $tagBody ) : array { return array_merge( $this->serviceLocator, [ 'name' => $tagName, 'body' => $tagBody, TypeContext::class => $context, ] ); } /** * Returns whether the given tag belongs to an annotation. * * @todo this method should be populated once we implement Annotation notation support. */ private function isAnnotation(string $tagContent) : bool { // 1. Contains a namespace separator // 2. Contains parenthesis // 3. Is present in a list of known annotations (make the algorithm smart by first checking is the last part // of the annotation class name matches the found tag name return false; } }