How can I get a product's image URL using service contracts?

Question

I know that in Magento 2.0, there is a recommended way to access products info from another module using service contracts.

So, my first question: how can I get a product's image URL using service contracts and an API function?

Second question: I want to override product's possible "getImageUrl" function so that I can generate a custom URL (points to an external source) and return it back as Image URL. So, any other external or internal module that wants to access a product's image's URL will get my generated URL instead of Magento's default product Image URL. Should it be implemented using service contracts ? Because its the recommended way in Magento 2.0.

Answer 1

Regarding your first question, I reckon you should use Magento\Catalog\Api\ProductAttributeMediaGalleryManagementInterface

Usual process you need to first inject the class in your constructor:

protected $_productMediaGalleryInterface;

public __construct(
    ...
    \Magento\Catalog\Api\ProductAttributeMediaGalleryManagementInterface $productMediaGalleryInterface
    ...
) {
    ...
    $this->_productMediaGalleryInterface = $productMediaGalleryInterface;
    ...
}

Then in your class, based on the product sku you can retrieve the list of gallerie entries associated with the given product:

$galleryEntries = $this->_productMediaGalleryInterface->getList($sku);

However, I'm pretty sure this won't give you all the data and maybe just a list of gallery entries.

To get information about a gallery entry you can call:

$galleryEntryData = this->_productMediaGalleryInterface->get($sku, $entryId);

Regarding your second question, I should you should use plugins.

Indeed, the getImageUrl is a public method for both Magento\Catalog\Helper\Product and Magento\Catalog\Block\Product\Gallery

Thus using a plugin with after statement you should be able to change the product image URL in a clean way.

I'm not too sure how service contracts would be relevant in that case. Service contracts are relevant when you add new type of database entities via a module and you need to do simple CRUD operations.