Magento 2 - Change Product Price if Custom Value is Selected

Question

I am using Magento 2.3.6

I have on the Product Page an Custom HTML Select Field: Yes / No

I want the price to Change if selected Field is set to "Yes" and keep the same price if it is set to "No".

At the moment i got this Product.php Class

namespace Vendor\Name\Model;

class Product
{
    protected $objectManager;

    public function __construct(\Magento\Framework\ObjectManagerInterface $objectManager)
    {
        $this->objectManager = $objectManager;
    }

    public function afterGetFinalPrice($product, $proceed) : float
    {
        return $proceed+10;
    }
} 

What i want is to set $proceed + 10 only if the Custom Produt Attribute is set to "Yes".

Under Vendor_Module/etc i have di.xml file

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Catalog\Model\Product">
        <plugin name="change_product" type="Vendor\Name\Model\Product" sortOrder="1"/>
    </type>
</config>

Any Ideas?

How can i get .phtml Value from Frontend into PHP File before adding to Shooping Cart?

Answer 1

Found the answer for my question.

Based on Renon Stewart Answer:

How to "add to cart" a product with custom input field and save it to Database?

In the addtocart.phtml view i created this block:

<select name="cloudways[isConfigured]" id="selectBlock">
        <option value="no">No</option>
        <option value="yes">Yes</option>
</select>

In the above example the passed attribute value would be the selected option of "isConfigured".

Than in The CheckoutCartProductAddAfterObserver Class i check for the attribute.

I created for it this function and check if the "key" equals "isConfigured" attribute value.

protected function isProductConfigured($post) {
    $isProductConfigured = '';
    if(is_array($post)){
        foreach($post as $key => $value){

            if($key == 'isConfigured'){
                    $isProductConfigured = $value;
            }
        }
    }
  return $isProductConfigured;
}

I call this function in the exectue(EventObserver $observer) function after

$post = $this->_request->getParam('cloudways');

if($this->isProductConfigured($post) == "yes") {

}

After that based on this answer:

Magento 2: setCustomPrice vs. setOriginalCustomPrice

I can update my Cart Price:

$price = $item->getProduct()->getFinalPrice()+10; 
$item->setCustomPrice($price);
$item->setOriginalCustomPrice($price);

Answer 2

you can add a new attribute with yes and no value and set for product using product attribute and set yes value + 10.