Automating Controller Factories

Writing a factory class for each and every controller that has dependencies can be tedious, particularly in early development as you are still sorting out dependencies.

As of version 3.0.1, zend-mvc ships with Zend\Mvc\Controller\LazyControllerAbstractFactory, which provides a reflection-based approach to controller instantiation, resolving constructor dependencies to the relevant services. The factory may be used as either an abstract factory, or mapped to specific controller names as a factory:

use Zend\Mvc\Controller\LazyControllerAbstractFactory;

return [
    /* ... */
    'controllers' => [
        'abstract_factories' => [
            LazyControllerAbstractFactory::class,
        ],
        'factories' => [
            'MyModule\Controller\FooController' => LazyControllerAbstractFactory::class,
        ],
    ],
    /* ... */
];

Mapping controllers to the factory is more explicit and performant.

The factory operates with the following constraints/features:

• 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 be resolved as null values.
• If a service cannot be found for a given typehint, the factory will raise an exception detailing this.
• Some services provided by Zend Framework components do not have entries based on their class name (for historical reasons); the factory contains a map of these class/interface names to the corresponding service name to allow them to resolve. These include:
  • Zend\Console\Adapter\AdapterInterface maps to ConsoleAdapter,
  • Zend\Filter\FilterPluginManager maps to FilterManager,
  • Zend\Hydrator\HydratorPluginManager maps to HydratorManager,
  • Zend\InputFilter\InputFilterPluginManager maps to InputFilterManager,
  • Zend\Log\FilterPluginManager maps to LogFilterManager,
  • Zend\Log\FormatterPluginManager maps to LogFormatterManager,
  • Zend\Log\ProcessorPluginManager maps to LogProcessorManager,
  • Zend\Log\WriterPluginManager maps to LogWriterManager,
  • Zend\Serializer\AdapterPluginManager maps to SerializerAdapterManager,
  • Zend\Validator\ValidatorPluginManager maps to ValidatorManager,

$options passed to the factory are ignored in all cases, as we cannot make assumptions about which argument(s) they might replace.

Once your dependencies have stabilized, we recommend writing a dedicated factory, as reflection can introduce performance overhead.

References

This feature was inspired by a blog post by Alexandre Lemaire.