我在哪里放置我的冗长的代码，准备在存储库中保存域对象？

Question

我有这样的代码：

/* Part of Controller::saveAction() */ 

//create new object instance
$item = new Item();

//populate the Item
$item->setDescription($description);
$item->setQuantity($quantity);
$item->setPrice($price);

//once we have a fully populated object, 
//send it to Repository pattern, 
//which saves it to persistent storage
$this->repository->saveItem($item);

想象一下在一个函数/方法中有几个像上面这样的块，你就会看到我的问题.我对我的repository代码行非常满意，但我不知道在调用Repository之前应该把所有的“准备工作”放在哪里。

问题：

在哪里放置大量创建和填充Item对象实例的代码？它把我的控制器方法弄得乱七八糟，我似乎无法想象有别的地方可以把它放进去。

目标

我的目标是找到好的结构/设计，而不是单纯地减少或减少“项目准备”行的数量。

根据Controller，我有大约5-7个Item实例，每个实例有10-16行代码创建和填充实例。

Answer 1

正如你所提到的，实现这一目标的正确途径。如何使用委托者并将控制器(块)分割成委托者？它的术语术语它将是外观适配器

在./module/MyModule/config/module.config.php中添加以下内容：

'controllers' => array(
    'invokables' => array(
        'MyModule\CreateController' => 'MyModule\Controller\MyController',
        'MyModule\ReadController' => 'MyModule\Controller\MyController',
    ),
    'delegators' => array(
        'MyModule\CreateController' => array(
            'MyModule\Controller\Delegator\CreateItemDelegatorFactory'
        ),
        'MyModule\ReadController' => array(
            'MyModule\Controller\Delegator\ReadItemDelegatorFactory'
        ),
    ),
),
'form_elements' => array(
    'invokables' => array(
        'item_create' => 'MyModule\Form\CreateForm',
    ),
),

创建代理程序加载表单，填充它，验证并尝试保存teh数据

./module/MyModule/src/MyModule/Controller/Delegator/CreateItemDelegatorFactory.php：

namespace MyModule\Controller\Delegator;

use Zend\ServiceManager\DelegatorFactoryInterface;
use Zend\ServiceManager\ServiceLocatorInterface;
use MyModule\Entity\Item as Entity;

/**
 *  Class loads the form, checks if form been posted and if is valid.
 *  If form is valid it tries to save the item with repository service
 *  Class sets the Form per controller, such solution keeps form      
 *  validation messages
 */
class CreateItemDelegatorFactory implements DelegatorFactoryInterface
{
   /**
    * Determines name of the form to be loaded with formElementManager
    * 
    * @var string
    */
   private $form_name = "item_create";

   /**
    * Name of repository service. It may be database, api or other
    *
    * @var string
    */
   private $service_repository_name = "service.repository";

   public function createDelegatorWithName(
        ServiceLocatorInterface $serviceLocator,
        $name,
        $requestedName,
        $callback
    ) {
        // assign serviceManager locally
        $parentLocator = $serviceLocator->getServiceLocator();
        // assign services locally
        $routerService = $parentLocator->get('router');
        $requestService = $parentLocator->get('request');
        // get repository service
        $repositoryService = $parentLocator->get($this->service_repository_name);

        // read the CreateForm with formElementManager and bind the Entity
        $callback->setForm(
             $parentLocator->get('FormElementManager')->get($this->form_name)
        );
        $entity = new Entity;
        $callback->getForm($this->form_name)->bind($entity);

        // check if data been posted   
        if($requestService->isPost()) {
            $postData = $requestService->getPost($this->form_name);
            $callback->getForm($this->form_name)->setData($postData);
            // validate form
            if($callback->getForm($this->form_name)->isValid()) {
                // form is valid
                $repositoryService->saveItem($entity);
            }
        }
    }
}

有了上面的代理程序，您的控制器(MyModule\ controller \MyController)将需要额外的属性和两个方法：

/**
 * Holds the form object
 * @var object
 */
private $form

public function setForm($form=null)
{
    $this->form = $form;
    return $this;
}

public function getForm()
{
    return $this->form;
}

./module/MyModule/src/MyModule/Controller/Delegator/ReadItemDelegatorFactory.php：

namespace MyModule\Controller\Delegator;

use Zend\ServiceManager\DelegatorFactoryInterface;
use Zend\ServiceManager\ServiceLocatorInterface;
use MyModule\Entity\Item as Entity;

/**
 * Creates Delegator which tries read item's id from the (segment type) route
 * and read the Item from the repository service
 *
 */
class ReadItemDelegatorFactory implements DelegatorFactoryInterface
{
    /**
     * Item's ID from route
     *
     * @var string
     */
    private $route_identifier = "item_id";

    /**
     * Name of repository service. It may be database, api or other
     *
     * @var string
     */
    private $service_repository_name = "service.repository";

    public function createDelegatorWithName(
        ServiceLocatorInterface $serviceLocator,
        $name,
        $requestedName,
        $callback
    ) {
        // assign serviceManager locally
        $parentLocator = $serviceLocator->getServiceLocator();
        // assign services locally
        $routerService = $parentLocator->get('router');
        $requestService = $parentLocator->get('request');
        // get repository service
        $repositoryService = $parentLocator->get($this->service_repository_name);
        // get the router match and the item_id
        $routerMatch = $routerService->match($requestService);
        $itemId = $routerMatch->getParam($this->route_identifier);
        // set the data for the target controller
        $callback->setItem($repositoryService->readItem($itemId));

        return $callback;
    }

有了上面的代理程序，您的控制器(MyModule\ controller \MyController)将需要额外的属性和方法：

/**
 * Holds the Item object
 * @var object \MyModule\Entity\Item
 */
private $item

public function setItem($item=null)
{
    $this->item = $item;
    return $this;
}

这种控制器的使用方式有助于代码保持干燥，并且似乎可以控制流程。委托程序被加载为LIFO，因此在将控制器($callback)传递给另一个代理程序之前，有可能预先配置它。

如果ReadController读取项，而CreateController加载表单，则UpdateItemDelegator处理item Update任务的方式很短。

'controllers' => array(
    'invokables' => array(
        'MyModule\UpdateController' => 'MyModule\Controller\MyController',
    'delegators' => array(
        'MyModule\ReadController' => array(
            'MyModule\Controller\Delegator\UpdateItemDelegatorFactory',
            'MyModule\Controller\Delegator\CreateItemDelegatorFactory',
            'MyModule\Controller\Delegator\ReadItemDelegatorFactory'
        ),
    ),
),

代表解释：http://ocramius.github.io/blog/zend-framework-2-delegator-factories-explained/

编辑：

为两个委派者(创建和读取)准备的控制器如下所示：

namespace MyModule\Controller;

use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;

class CreateController extends AbstractActionController
{
    /**
     * Holds the Item object
     * @var object \MyModule\Entity\Item
     */
    private $item

    /**
     * Holds the form object
     * @var mixed null|object
     */
    private $form;

     /**
      * Item's details. It reads item by the `item_id` which is param set in route with same name
      * @return \Zend\View\Model\ViewModel
      */
     public function readAction()
     {
         $v = new ViewModel();
         // set item, access it in template as `$this->item`
         $v->setVariable('item',$this->getItem());

         return $v;
     }

     /**
      * The Form preconfigured with CreateItemDelegatorFactory should be av. in template as `$this->form`
      * @return \Zend\View\Model\ViewModel
      */
     public function createAction()
     {
         $v = new ViewModel();
         // set form, access the in template as `$this->form`
         $v->setVariable('form',$this->getForm());

         return $v;
     }

    /**
     * Sets the Item object
     * @var $item \MyModule\Entity\Item
     * @return $this
     */
     public function setItem($item=null)
     {
         $this->item = $item;
         return $this;
     }

     /**
     * Gets the Item object
     * @return object \MyModule\Entity\Item
     */
     public function getItem()
     {
        return $this->item;
     }

     public function setForm($form=null)
     {
        $this->form = $form;
        return $this;
     }

     /**
      * Returns form defined in config and CreateItemDelegatorFactory::form_name
      * @return \Zend\Form\Form
      */
     public function getForm()
     {
         return $this->form;
     }
}

Answer 2

观测

像$description, $quantity, $price这样的单个值必须来自某个地方。它可以是GET、POST、SESSION、COOKIES或数据库或外部方法。为了清晰起见，我们将其命名为$_SOMEWHERE。然后我们得到：

$description = $_SOMEWHERE['description'];
$quantity = $_SOMEWHERE['quantity'];
$price = $_SOMEWHERE['price'];

定义一个用于为您工作并返回准备好的Item的输入和准备类。

class AcquireItem
{
    function getItem()
    {
        $item = new Item();

        $item->setDescription($_SOMEWHERE['description']);
        $item->setQuantity($_SOMEWHERE['quantity']);
        $item->setPrice($_SOMEWHERE['price']);

        return $item;
    }
}

控制器

$item = (new AcquireItem())->getItem();
$this->repository->saveItem($item);

控制器变得更短，有效地将庞大的杂波代码“填塞”到一个与读取和准备输入有关的类中，并将控制器解出。代码必须存在于某个地方，但也可能是不可见的，或者是其他地方。

对于不同类型的Item，可以更改方法，即getItemA()、getItemB()。

Answer 3

我个人认为创建方法应该进入存储库。这是因为我希望存储库包含所有CRUD (创建、读取、更新、删除)方法。

这只是我对这个话题的个人想法..。