From 8f73d7932bc227bac55642acb538000762d31e99 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Frank=20Br=C3=BCckner?= Date: Thu, 4 Apr 2024 08:18:14 +0200 Subject: [PATCH] Update documentation for Reflection Abstract Factory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The documentation for Reflection Abstract Factory has been updated to improve the clarity and flow of the information. The changes include rewording for better understanding, reordering of sections for better logical progression, and additional warnings and recommendations concerning performance issues and alternatives. Signed-off-by: Frank Brückner --- docs/book/v4/reflection-abstract-factory.md | 93 ++++++++++++--------- 1 file changed, 53 insertions(+), 40 deletions(-) diff --git a/docs/book/v4/reflection-abstract-factory.md b/docs/book/v4/reflection-abstract-factory.md index 20af5f5a..e7a40cda 100644 --- a/docs/book/v4/reflection-abstract-factory.md +++ b/docs/book/v4/reflection-abstract-factory.md @@ -1,67 +1,80 @@ # Reflection Factory -Writing a factory class for each and every service that has dependencies -can be tedious, particularly in early development as you are still sorting -out dependencies. +## Service Auto Wiring -laminas-servicemanager ships with `Laminas\ServiceManager\AbstractFactory\ReflectionBasedAbstractFactory`, -which provides a reflection-based approach to instantiation, resolving -constructor dependencies to the relevant services. The factory may be used as -either an abstract factory, or mapped to specific service names as a factory: +Writing a factory class for each and every service that has dependencies can be tedious, particularly in early development as you are still sorting out dependencies. + +To alleviate this issue, laminas-servicemanager ships with the `ReflectionBasedAbstractFactory`, which provides a [reflection-based approach](https://www.php.net/manual/intro.reflection.php) to instantiation, resolving constructor dependencies to the relevant services. + +The factory operates with the following features/constraints: + +- A parameter named `$config` type-hinted as an array will receive the application "config" service (i.e., the merged configuration). +- Parameters type-hinted against array, but not named `$config`, will be injected with an empty array. +- Scalar parameters will result in the factory raising an exception, unless a default value is present; if it is, that value will be used. +- If a service cannot be found for a given typehint, the factory will raise an exception detailing this. + +WARNING: `$options` passed to the factory are ignored in all cases, as we cannot make assumptions about which argument(s) they might replace. + +## Usage + +The factory may be used as either an abstract factory or mapped to specific service names as a factory. +The following sections detail how to configure the `ReflectionBasedAbstractFactory` for each use case. + +### Usage as an Abstract Factory + +To use the `ReflectionBasedAbstractFactory` as an [abstract factory](configuring-the-service-manager.md#abstract-factories), add it to the `abstract_factories` configuration: ```php use Laminas\ServiceManager\AbstractFactory\ReflectionBasedAbstractFactory; return [ - /* ... */ + // … 'service_manager' => [ 'abstract_factories' => [ ReflectionBasedAbstractFactory::class, ], - 'factories' => [ - 'MyModule\Model\FooModel' => ReflectionBasedAbstractFactory::class, - ], ], - /* ... */ + // … ]; ``` -Mapping services to the factory is more explicit and even more performant than in v3.0 due to the [ahead of time factory generation](cli-commands/generate-ahead-of-time-factories.md). +With this configuration, any service that **cannot be found** in the service manager will be created using the `ReflectionBasedAbstractFactory`. + +### Usage as a Factory + +To use the `ReflectionBasedAbstractFactory` as a factory for a specific service, map it to the service name in the `factories` configuration: -The factory operates with the following constraints/features: +```php +use Laminas\ServiceManager\AbstractFactory\ReflectionBasedAbstractFactory; -- A parameter named `$config` typehinted as an array will receive the - application "config" service (i.e., the merged configuration). -- Parameters typehinted against array, but not named `$config`, will - be injected with an empty array. -- Scalar parameters will result in the factory raising an exception, - unless a default value is present; if it is, that value will be used. -- If a service cannot be found for a given typehint, the factory will - raise an exception detailing this. +return [ + // … + 'service_manager' => [ + 'factories' => [ + 'MyModule\Model\FooModel' => ReflectionBasedAbstractFactory::class, + ], + ], + // … +]; +``` -`$options` passed to the factory are ignored in all cases, as we cannot -make assumptions about which argument(s) they might replace. +With this configuration, the `ReflectionBasedAbstractFactory` will be used to create the `MyModule\Model\FooModel` service. -Once your dependencies have stabilized, we recommend providing a dedicated -factory, as reflection introduces a performance overhead. +## Performance Improvements +Once the dependencies have stabilized and when performance is a requirement, it is recommended writing a dedicated factory, as reflection _can_ introduce performance overhead. There are two ways to provide dedicated factories for services consuming `ReflectionBasedAbstractFactory`: -1. Usage of the [generate-factory-for-class console tool](cli-commands/generate-factory-for-class.md) (this will also require to manually modify the configuration) -2. Usage of the [generate-aot-factories console tool](cli-commands/generate-ahead-of-time-factories.md) which needs an initial project + deployment setup +1. Usage of the [generate-factory-for-class CLI command](cli-commands/generate-factory-for-class.md) (this will also require to manually modify the configuration) +2. Usage of the [generate-aot-factories CLI command](cli-commands/generate-ahead-of-time-factories.md) which needs an initial project + deployment setup -## Alternatives - -You may also use the [Config Abstract Factory](config-abstract-factory.md), -which gives slightly more flexibility in terms of mapping dependencies: +TIP: +In many applications, the `ReflectionBasedAbstractFactory` can also be used on productive systems without any problems or losses, so there is no need to create or generate dedicated factories. -- If you wanted to map to a specific implementation, choose the - `ConfigAbstractFactory`. -- If you need to map to a service that will return a scalar or array (e.g., a - subset of the `'config'` service), choose the `ConfigAbstractFactory`. -- If you need a faster factory for production, choose the - `ConfigAbstractFactory` or create a custom factory. +## Alternatives -## References +It is also possible to use the [Config Abstract Factory](config-abstract-factory.md), which is slightly more flexibility in terms of mapping dependencies: -This feature was inspired by [a blog post by Alexandre Lemaire](http://circlical.com/blog/2016/3/9/preparing-for-zend-f). +- If you wanted to map to a specific implementation, choose the `ConfigAbstractFactory`. +- If you need to map to a service that will return a scalar or array (e.g., a subset of the `'config'` service), choose the `ConfigAbstractFactory`. +- If you need a faster factory for production, choose the `ConfigAbstractFactory` or create a custom factory.