Factories
Factories are service classes that instantiate non-injectable classes, that is, models that represent a database entity.
They create a layer of abstraction between the ObjectManager
and business code.
Relationship to ObjectManager
The Magento\Framework\ObjectManager
is the class responsible for instantiating objects in the application.
Adobe Commerce and Magento Open Source prohibit depending on and directly using the ObjectManager
in your code.
Factories are an exception to this rule because they require the ObjectManager
to instantiate specific models.
The following example illustrates the relationship between a simple factory and the ObjectManager
:
Copied to your clipboard<?php/*** Copyright © Magento, Inc. All rights reserved.* See COPYING.txt for license details.*/namespace Magento\Framework\App\Config;use Magento\Framework\ObjectManagerInterface;use Magento\Framework\Simplexml\Element;use Magento\Framework\App\Config\Base;class BaseFactory{/*** @var ObjectManagerInterface*/protected $_objectManager;/*** @param ObjectManagerInterface $objectManager*/public function __construct(ObjectManagerInterface $objectManager){$this->_objectManager = $objectManager;}/*** Create config model** @param string|Element $sourceData* @return Base*/public function create($sourceData = null): Base{return $this->_objectManager->create(Base::class, ['sourceData' => $sourceData]);}}
Writing factories
Unless you require specific behavior for your factory classes, you do not need to explicitly define them because they are an automatically generated class type. When you reference a factory in a class constructor, Magento's object manager generates the factory class if it does not exist.
Factories follow the naming convention <class-type>Factory
where <class-type>
is the name of the class the factory instantiates.
For example the automatically generated Magento\Cms\Model\BlockFactory
class is a factory that instantiates the class Magento\Cms\Model\Block
.
Using factories
You can get the singleton instance of a factory for a specific model using dependency injection.
The following example shows a class getting the BlockFactory
instance through the constructor:
Copied to your clipboardpublic function __construct ( \Magento\Cms\Model\BlockFactory $blockFactory) {$this->blockFactory = $blockFactory;}
Calling the create()
method on a factory gives you an instance of its specific class:
Copied to your clipboard$block = $this->blockFactory->create();
For classes that require parameters, the automatically generated create()
function accepts an array of parameters that it passes on to the ObjectManager
to create the target class.
The example below shows the construction of a \Magento\Framework\FlagFactory
object by passing in an array of parameters to a factory:
Copied to your clipboard$flag = $this->flagFactory->create(['data' => ['flag_code' => 'something']]);
The Flag
class has a $data
constructor parameter which corresponds to the data key in the create
array above.
Interfaces
Factories are smart enough to resolve dependencies and allow you to get the correct instance of an interface as defined in your module's di.xml
.
For example, in the CatalogInventory
module, the di.xml
file contains the following entry:
Copied to your clipboard<preference for="Magento\CatalogInventory\Api\Data\StockItemInterface" type="Magento\CatalogInventory\Model\Stock\Item" />
It instructs the application to use the specific Item
class wherever the StockItemInterface
is used.
When a class in that module includes the factory StockItemInterfaceFactory
as a dependency, the application generates a factory that is capable of creating the specific Item
objects.