What is a «virtualType» and how to use it?

dmitry_fedyuk · October 31, 2015, 8:24pm

Look at the catalog_product_link widget declaration:

magento/magento2/blob/550f10ef2bb6dcc3ba1ea492b7311d7a80d01560/app/code/Magento/Catalog/etc/widget.xml#L87-L90


<widget id="catalog_product_link"
        class="Magento\Catalog\Block\Product\Widget\Link"
        is_email_compatible="true"
        placeholder_image="Magento_Catalog::images/product_widget_link.png">

There is no class Magento\Catalog\Block\Product\Widget\Link, it is a virtual type:

github.com

magento/magento2/blob/550f10ef2bb6dcc3ba1ea492b7311d7a80d01560/app/code/Magento/Catalog/etc/di.xml#L387-L391


<virtualType name="Magento\Catalog\Block\Product\Widget\Link" type="Magento\Catalog\Block\Widget\Link">
    <arguments>
        <argument name="entityResource" xsi:type="object">Magento\Catalog\Model\ResourceModel\Product</argument>
    </arguments>
</virtualType>

So Magento\Catalog\Block\Product\Widget\Link is an alias to Magento\Catalog\Block\Widget\Link, but with a custom dependency injection: an argument entityResource has a type Magento\Catalog\Model\ResourceModel\Product.

Look at the Magento\Catalog\Block\Widget\Link constructor:

github.com

magento/magento2/blob/550f10ef2bb6dcc3ba1ea492b7311d7a80d01560/app/code/Magento/Catalog/Block/Widget/Link.php#L53-L62


public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    UrlFinderInterface $urlFinder,
    \Magento\Catalog\Model\ResourceModel\AbstractResource $entityResource = null,
    array $data = []
) {
    parent::__construct($context, $data);
    $this->urlFinder = $urlFinder;
    $this->_entityResource = $entityResource;
}

As you can see a normal Magento\Catalog\Block\Widget\Link instance will have an argument entityResource of type Magento\Catalog\Model\ResourceModel\AbstractResource.

By using virtualType declaration we inject the custom entityResource of type Magento\Catalog\Model\ResourceModel\Product.

Here is an explanation on StackExchange: http://magento.stackexchange.com/a/33140/18793

dmitry_fedyuk · February 27, 2016, 6:39pm

Example 2

github.com

magento/magento2/blob/cf7df72/app/code/Magento/Payment/etc/di.xml#L27-L31


<type name="Magento\Payment\Model\Config">
    <arguments>
        <argument name="dataStorage" xsi:type="object">Magento\Payment\Model\Config\Data</argument>
    </arguments>
</type>

github.com

magento/magento2/blob/cf7df72/app/code/Magento/Payment/etc/di.xml#L21-L26


<virtualType name="Magento\Payment\Model\Config\Data" type="Magento\Framework\Config\Data">
    <arguments>
        <argument name="reader" xsi:type="object">Magento\Payment\Model\Config\Reader\Proxy</argument>
        <argument name="cacheId" xsi:type="string">payment_config</argument>
    </arguments>
</virtualType>

eric128 · June 23, 2016, 6:04am

Rewrite/Plugin does not work with virtualType. For example, I rewrite function _getProductCollection in magento/module-catalog/Block/Product/ListProduct.php does not work in page search result. Because page search uses a virtualType class which is defined in magento/module-catalog-search/etc/frontend/di.xml

dmitry_fedyuk · June 27, 2016, 2:43am

What do you mean by “rewrite function”?

dmitry_fedyuk · March 3, 2017, 10:52am