Magento 2 StoreManagerInterface already exists in context object in compilation

Question

I am getting this error in my extension.

PackageName\ModuleName\Block\Enhanced
Incorrect dependency in class PackageName\ModuleName\Block\Enhanced in /var/www/html/app/code/PackageName/ModuleName/Block/Enhanced.php \Magento\Store\Model\StoreManagerInterface already exists in context object

 public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Catalog\Model\Session $catalogSession,
    \Magento\Store\Model\StoreManagerInterface $storeManager,        
    array $data = []

)
{
    parent::__construct($context, $data);
    $this->_catalogSession = $catalogSession;
    $this->_storeManager = $storeManager;      
}

Answer 1

You don't need to inject \Magento\Store\Model\StoreManagerInterface in your constructor because the parent class already does that.

I assume your block extends Magento\Framework\View\Element\Template which already has the following code:

protected $_storeManager;

public function __construct(Template\Context $context, array $data = [])
{
    $this->validator = $context->getValidator();
    $this->resolver = $context->getResolver();
    $this->_filesystem = $context->getFilesystem();
    $this->templateEnginePool = $context->getEnginePool();
    $this->_storeManager = $context->getStoreManager();
    $this->_appState = $context->getAppState();
    $this->templateContext = $this;
    $this->pageConfig = $context->getPageConfig();
    parent::__construct($context, $data);
}

Thus you can replace your code with:

public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Catalog\Model\Session $catalogSession,   
    array $data = []

)
{
    parent::__construct($context, $data);
    $this->_catalogSession = $catalogSession;
}

Answer 2

you don't need to add \Magento\Store\Model\StoreManagerInterface $storeManager as a dependency to your class.
You already have access to an inplementation of StoreManagerInterface in the Magento\Framework\View\Element\Template\Context class.
See this.

So you can make your constructor look like this:

public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Catalog\Model\Session $catalogSession,
    array $data = []

)
{
    parent::__construct($context, $data);
    $this->_catalogSession = $catalogSession;
}

And you will still be able to access storeManager member variable like this $this->_storeManager.

Answer 3

Following methods are available in Context object(\Magento\Framework\View\Element\Template\Context)

print_r(get_class_methods($context))

Array
(
    [0] => __construct
    [1] => getResolver
    [2] => getValidator
    [3] => getFilesystem
    [4] => getLogger
    [5] => getViewFileSystem
    [6] => getEnginePool
    [7] => getAppState
    [8] => getStoreManager
    [9] => getPageConfig
    [10] => getCache
    [11] => getDesignPackage
    [12] => getEventManager
    [13] => getLayout
    [14] => getRequest
    [15] => getSession
    [16] => getSidResolver
    [17] => getScopeConfig
    [18] => getInlineTranslation
    [19] => getUrlBuilder
    [20] => getAssetRepository
    [21] => getViewConfig
    [22] => getCacheState
    [23] => getEscaper
    [24] => getFilterManager
    [25] => getLocaleDate
)