I have a collection.php file. I am adding some function into that which calls other models.As per Magento 2 first we have to add object managerger interface. And then we can call other model.like below :


To use $this->_objectManger we have to define in __Construct first. Now I am doing same thing in __Construct method of Collection.php file. But it is not working and creating issues.

Please check code : Collection.php

namespace \Namespace\Module\Model\ResourceModel\Testfile;

class Collection extends \Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection

 public function __construct(
    **\Magento\Framework\ObjectManagerInterface $objectManager,** 
    \Magento\Framework\Data\Collection\EntityFactory $entityFactory,
    \Psr\Log\LoggerInterface $logger,
    \Magento\Framework\Data\Collection\Db\FetchStrategyInterface $fetchStrategy,
    \Magento\Framework\Event\ManagerInterface $eventManager,
    \Magento\Catalog\Model\ResourceModel\Product\Option\Value\CollectionFactory $optionValueCollectionFactory,
    \Magento\Store\Model\StoreManagerInterface $storeManager,
    \Magento\Framework\DB\Adapter\AdapterInterface $connection = null,
    \Magento\Framework\Model\ResourceModel\Db\AbstractDb $resource = null
) {
    $this->_optionValueCollectionFactory = $optionValueCollectionFactory;
    $this->_storeManager = $storeManager;
    parent::__construct($entityFactory, $logger, $fetchStrategy, $eventManager, $connection, $resource);
    $this->logger = $logger; 
    $this->_objectManager = $objectManager;

How to add extra classes in this ? Please explain where I am wrong and why.

  • @ Krupali Please share the error you are getting. Jun 22, 2016 at 11:16

1 Answer 1


Please explain where I am wrong and why.

You should not require the object manager itself as dependency in the constructor, instead require the object you need directly:

public function __construct(
    \Namespace\Module\Model\Customfile $customfile
) {
    $this->customfile = $customfile;

Then use it like this:


This will use a shared instance of the Customfile model (like a singleton in Magento 1). If you need a new instance every time, you can use the automatically generated factory.

With Factory:

public function __construct(
    \Namespace\Module\Model\CustomfileFactory $customfileFactory
) {
    $this->customfileFactory = $customfileFactory;


$customfile = $this->customFileFactory->create();

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