how to check if product has a shopping cart rule or not in magento 2

Question

I have tried these

$currentDate = $this->_stdTimezone->date()->format('Y-m-d');
        $rules = $this->collection->create()
                        ->addFieldToFilter('is_active', 1)
                        ->addFieldToFilter('from_date', ['lteq' => $currentDate])
                        ->addFieldToFilter('from_date', ['neq' => 'NULL']);
        $product = $this->_coreRegistry->registry('product');
            foreach ($rules as $rule) {
            try {
                if ($rule->getActions()->validate($product)) {
                        $activeRules[] = $rule;

                }
            } catch (\Magento\Framework\Exception\NoSuchEntityException $e) {
                continue;
            }
        }
        $rulesApplied = "";
        foreach ($rules as $rule) {
                $code = $rule->getCode();
                $rulesApplied .= "<strong>".$code."</strong>"."</br>";
        }
        return $rulesApplied;

but i am getting all the rules which are satisfying the given conditions.I need only the rules which are applied to a products.

Answer 1

Based on product sku i am able to display the promo code rule

class Coupons extends \Magento\Framework\View\Element\Template
{
/**
 * Core registry
 *
 * @var \Magento\Framework\Registry
 */
protected $_coreRegistry = null;

/**
 * @param \Magento\Framework\View\Element\Template\Context $context
 * @param \Magento\Framework\Registry $registry
 * @param array $data
 */
public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,
    \Magento\Framework\Registry $registry,
    \Magento\SalesRule\Model\ResourceModel\Rule\CollectionFactory  $collection,
    \Magento\Framework\Stdlib\DateTime\Timezone $_stdTimezone,
    array $data = []
) {
    $this->_coreRegistry = $registry;
    $this->collection = $collection;
    $this->_stdTimezone = $_stdTimezone;
    parent::__construct($context, $data);
}


public function getDiscount()
{

    $currentDate = $this->_stdTimezone->date()->format('Y-m-d');
    $rules = $this->collection->create()
                    ->addFieldToFilter('is_active', 1)

                    ->addFieldToFilter('from_date', ['lteq' => $currentDate])
                    ->addFieldToFilter('from_date', ['neq' => 'NULL']);

    $product = $this->_coreRegistry->registry('product');
     /** @var \Magento\SalesRule\Model\Rule $rule */
        foreach ($rules as $rule) {
        try {
            if ($rule->getActions()->validate($product)) {
                    $activeRules[] = $rule;

            }
        } catch (\Magento\Framework\Exception\NoSuchEntityException $e) {
            continue;
        }
    }
    $rulesApplied = "";
    $productsku = $product->getSku();
    foreach ($rules as $rule) {
        if ($rule->getIsActive()) {
        $condition_ser = $rule->getConditionsSerialized();
        $unserialized_conditions = json_decode($condition_ser);
        if(isset($unserialized_conditions->conditions[0]->conditions[0]->value)){
        $explode_array = explode(",", $unserialized_conditions->conditions[0]->conditions[0]->value); 
        $code="";
        for($j=0;$j<count($explode_array);$j++)
            {

                if(trim($explode_array[$j])==$productsku)
                {

                    $code.= $rule->getCode();
                    $rulesApplied .= "<strong>".$code."</strong>"."</br>";
                }

            }
        }

        }               
    }

    return $rulesApplied;
}
} 

Answer 2

There could be different conditions which identify a assigned or affected product.

I would implement such a requirement by defining the product attribute which has to be used/set in a action condition within a cart rule and than validate those condition by looping all currently active rules.

Best practice: SKU