Use \Magento\Catalog\Helper\Image::getUrl().
fad606f29aa039b8e6d746a774508274b5f7c560/Core/lib/catalog.php?ts=4#L27-L72
/**
* 2016-04-23
* How to get an image URL for a product programmatically?
* https://mage2.pro/t/1313
* How is @uses \Magento\Catalog\Helper\Image::getUrl() implemented and used?
* https://mage2.pro/t/1316
* @param Product $product
* @param string|null $type [optional]
* @param array(string => string) $attrs [optional]
* @return string
*/
function df_product_image_url(Product $product, $type = null, $attrs = []) {
/** @var string|null $result */
if ($type) {
$result = df_catalog_image_h()
->init($product, $type, ['type' => $type] + $attrs + df_view_config()->getMediaAttributes(
'Magento_Catalog', ImageHelper::MEDIA_TYPE_CONFIG_NODE, $type
))
->getUrl()
;
}
else {
/**
* 2016-05-02
* How is @uses \Magento\Catalog\Model\Product::getMediaAttributes() implemented and used?
* https://mage2.pro/t/1505
* @var string[] $types
*/
$types = array_keys($product->getMediaAttributes());
// Give priority to the «image» attribute.
/** @var int|null $key */
$key = array_search('image', $types);
if (false !== $key) {
unset($types[$key]);
array_unshift($types, 'image');
}
$result = '';
foreach ($types as $type) {
$result = df_product_image_url($product, $type, $attrs);
if ($result) {
break;
}
}
}
return $result;
}