Can't Override or Plugin Magento\Quote\Model\Cart\ShippingMethodManagement

[MageMagicLLC]

I must be not understanding something. When I try to override or extend via plugin the Magento\Quote\Model\Cart\ShippingMethodManagement class it just doesn't work. Here's my code:

frontend/di.xml

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\Quote\Model\ShippingMethodManagement">
    <plugin name="vnsShippingmethodmanagement" type="VNS\Shippingquote\Model\ShippingMethodManagement" sortOrder="1"/>
</type>

Model/ShippingMethodManagement.php

public function __construct(    \Magento\Catalog\Api\ProductRepositoryInterface $productRepository) {    $this->productRepository = $productRepository;
}

private function afterGetShippingMethods(Quote $quote, $output)
{    error_log('test');
}

Module is installed/enabled, cache cleared, genereated/ deleted.

[maiuock8c · Accepted solution]

Hi 

I see this is private method so you can not use Plugin for this case. 

Plugins cannot be used with any of the following:

• Final methods
• Final classes
• Non-public methods
• Static methods
• __construct
• Virtual types
• Objects that are instantiated before Magento\Framework\Interception is bootstrapped
• Objects that are not instantiated by the ObjectManager (e.g. by using new directly).
  
  

You can read more on Magento document https://devdocs.magento.com/guides/v2.0/extension-dev-guide/plugins.html

[MageMagicLLC]

Thanks for this. That makes sense. Is this also why I can't override it using <preference?

[MageMagicLLC]

This is solved now. I found out that to override it I need to include all the public and private functions so I basically copied ShippingMethodManagement.php from the core to my module and added the things I needed. It's working great now. Thanks!

[sunilkumare177]

I am also overriding same function can you tell how you override it.

I also used the preference method but getting the type error and then run di:compile command but its not solve that issue .

Can you tell me how you solved that