How to create a new price type?

Question

I am now struggling to create a new price type on Magento 2.2.7. Below are what I have tried so far.

I have created a module Foo_Bar.

And then, first of all, inject the new type into the price pool:

Foo\Bar\etc\di.xml

<virtualType name="Magento\Catalog\Pricing\Price\Pool">
    <arguments>
        <argument name="prices" xsi:type="array">
            <item name="custom_price" xsi:type="string">Foo\Bar\Pricing\Price\CustomPrice</item>
        </argument>
    </arguments>
</virtualType>

Define the price class:

Foo\Bar\Pricing\Price\CustomPrice.php

namespace Foo\Bar\Pricing\Price;

use Magento\Framework\Pricing\Price\AbstractPrice;

class CustomPrice extends AbstractPrice {
    const PRICE_CODE = 'custom_price';

    public function getValue() {
        return '1234'; // for testing purpose
    }
}

I have deleted all files under generated/code, generated/metadata, and I have run all the commands I could think of:

php bin/magento s:d:c
php bin/magento c:c
php bin/magento c:f

Then, for testing purpose, I tried to edit the core block Magento\Catalog\Pricing\Render\FinalPriceBox and added some codes in the function _toHtml() as follows:

echo 'final_price: ' . $this->getPriceType('final_price')->getAmount()->getValue() . '<br/>';
echo 'regular_price: ' . $this->getPriceType('regular_price')->getAmount()->getValue() . '<br/>';
echo 'base_price: ' . $this->getPriceType('base_price')->getAmount()->getValue() . '<br/>';
echo 'tier_price: ' . $this->getPriceType('tier_price')->getAmount()->getValue() . '<br/>';
echo 'special_price: ' . $this->getPriceType('special_price')->getAmount()->getValue() . '<br/>';
// the following line is commented out because it is giving me another irrelevant error about illegal offset
//echo 'custom_option_price: ' . $this->getPriceType('custom_option_price')->getAmount()->getValue() . '<br/>';
echo 'configured_price: ' . $this->getPriceType('configured_price')->getAmount()->getValue() . '<br/>';
echo 'configured_regular_price: ' . $this->getPriceType('configured_regular_price')->getAmount()->getValue() . '<br/>';
echo 'catalog_rule_price: ' . $this->getPriceType('catalog_rule_price')->getAmount()->getValue() . '<br/>';
echo 'msrp_price: ' . $this->getPriceType('msrp_price')->getAmount()->getValue() . '<br/>';
echo 'wishlist_configured_price: ' . $this->getPriceType('wishlist_configured_price')->getAmount()->getValue() . '<br/>';
// the line below would result in an exception
//echo 'custom_price: ' . $this->getPriceType('custom_price')->getAmount()->getValue() . '<br/>';
die();

Basically what I was trying to do is to see if I could retrieve the price type I defined earlier. All the lines except the two I have commented out worked properly. And the last line is giving me an exception like this:

Exception #0 (ReflectionException): Class  does not exist

And part of the related traces:

/vendor/magento/framework/Pricing/Price/Collection.php(138): Magento\Framework\Pricing\Price\Factory->create(Object(Magento\Catalog\Model\Product\Interceptor), NULL, NULL)
/vendor/magento/framework/Pricing/PriceInfo/Base.php(63): Magento\Framework\Pricing\Price\Collection->get('custom_price')
/vendor/magento/framework/Pricing/Render/PriceBox.php(135): Magento\Framework\Pricing\PriceInfo\Base->getPrice('custom_price')
/vendor/magento/module-catalog/Pricing/Render/FinalPriceBox.php(97): Magento\Framework\Pricing\Render\PriceBox->getPriceType('custom_price')
/vendor/magento/framework/View/Element/AbstractBlock.php(667): Magento\Catalog\Pricing\Render\FinalPriceBox->_toHtml()

And from Magento\Framework\Pricing\Price\Factory->create(Object(Magento\Catalog\Model\Product\Interceptor), NULL, NULL), we could find some hints in Magento\Framework\Pricing\Price\Collection:

Magento\Framework\Pricing\Price\Collection

public function get($code)
{
    if (!isset($this->priceModels[$code])) {
        $this->priceModels[$code] = $this->priceFactory->create(
            $this->saleableItem,
            $this->pool[$code],
            $this->quantity
        );
    }
    return $this->priceModels[$code];
}

From here we could see that $this->pool[$code] which would be $this->pool['custom_price'] in this case, is NULL. This made me think that my custom price type is still nowhere to be found inside the price pool.

What am I missing here?

I hope I am clear enough and thanks for any assistance in advance.

---

UPDATE

Actually, the price code I used for my testing was original_price instead of custom_price. I just found that if I change the code to custom_price, it worked properly. But any values other than that would result in the same failure as above.

Answer 1

Try switching your di.xml content with the following (use your own class names)

<virtualType name="MyVendor\MyModule\Pricing\Price\Pool" type="Magento\Framework\Pricing\Price\Pool">
  <arguments>
      <argument name="prices" xsi:type="array">
          <item name="custom_price" xsi:type="string">MyVendor\MyModule\Pricing\Price\MyPrice</item>
      </argument>
      <argument name="target" xsi:type="object">Magento\Catalog\Pricing\Price\Pool</argument>
  </arguments>
</virtualType>

Recompile code, and test again.