How to Add Additional Options in Magento 2 and convert it into order?

Question

I need to add my custom detail in cart along with product detail and transfer these details in order too. I want to use additional option functionality for this.

Answer 1

1. For AddtoCart add events.xml file in app/code/[VendorName]/CustomModule/etc/frontend folder

<event name="checkout_cart_product_add_after">
    <observer name="customprice" instance="[VendorName]\CustomModule\Observer\CustomPrice" />
</event>

2. Create CustomPrice.php file on [VendorName]\CustomModule\Observer folder

<?php
namespace [VendorName]\CustomModule\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\App\RequestInterface;
use Magento\Framework\Serialize\Serializer\Json;
use Magento\Framework\App\ObjectManager;

class CustomPrice implements ObserverInterface
{
    /**
     *
     * @var type \Magento\CatalogRule\Model\Rule 
     */
    protected $rule;
    /**
     * 
     * @param RequestInterface $request
     * @param \Magento\CatalogRule\Model\Rule $rule
     */
    public function __construct(
        \Magento\Framework\App\RequestInterface $request,
        \Magento\CatalogRule\Model\Rule $rule,
        Json $serializer = null
    )
    {
        $this->rule = $rule;
        $this->_request = $request;
        $this->serializer = $serializer ?: ObjectManager::getInstance()->get(Json::class);
    }
    
    /**
     * 
     * @param \Magento\Framework\Event\Observer $observer
     */
    public function execute(\Magento\Framework\Event\Observer $observer) {
        $optionsSize = $this->_request->getPost('options-size')?$this->_request->getPost('options-size'):'';
        $optionsFinish = $this->_request->getPost('options-finish')?$this->_request->getPost('options-finish'):'';
        $optionsCminch = $this->_request->getPost('options-finish')?$this->_request->getPost('cminch'):'in';
        $customizationDetails = $this->_request->getPost('customization_details')?$this->_request->getPost('customization_details'):'';
        
        /* Default option */
        $item = $observer->getEvent()->getData('quote_item');         
        $item = ( $item->getParentItem() ? $item->getParentItem() : $item );
        $product = $item->getProduct();

        $candidates['value'] = 0.00;
        $candidates['order_quantity'] = 0;

        if($product->getTypeId() != 'giftvoucher'){
            $finishOption = array(
                'label' => 'Finish',
                'value' => 'Natural',
            );
            $sizeOption = array(
                'label' => 'Size',
                'value' => $product->getDefaultHeight().' W X '.$product->getDefaultWidth().' H inch',
            );
            $productId = $product->getId();

            if($optionsSize || $optionsFinish)
            {
                $customPrice = $item->getProduct()->getFinalPrice();
                $productId = $this->_request->getPost('product');
                if($optionsSize)
                {
                    $customSize = explode(':',$optionsSize);
                    $unitPrice = $product->getUnitPrice();
                    $fixedPrice = $product->getFixedPrice();
                    $customPrice = ceil(($unitPrice*$customSize[0]*$customSize[1]/10000)+$fixedPrice);
                    if($optionsCminch=='cm')
                    {
                    $sizeOption = array(
                             'label' => 'Size',
                             'value' => $customSize[0].' W X '.$customSize[1].' H cm',
                        );
                    }else{
                        $sizeOption = array(
                             'label' => 'Size',
                             'value' => round($customSize[0]*0.393701).' W X '.round($customSize[1]*0.393701).' H inch',
                        );
                    }
                    //$itemsOptions[] = $sizeOption;
                    $weight = round(($customSize[0] * $customSize[1] / 10000) * 18);
                    $weight = ceil(2.20462 * $weight);
                    $item->setWeight($weight);
                }
                if($optionsFinish){
                    $customFinish = json_decode(trim($optionsFinish), true);
                    $customPrice = $customPrice + ceil($customPrice*$customFinish['price']/100);
                    $finishOption = array(
                             'label' => 'Finish',
                             'value' => $customFinish['title'],
                        );
                    //$itemsOptions[] = $finishOption;
                }
                if($customizationDetails){
                    $customizationArray = array(
                             'label' => 'Details',
                             'value' => $customizationDetails,
                        );
                    $itemsOptions['Details'] = $customizationArray;
                }
                //$item->getCustomTierPrice($customPrice);
                $objectManager = \Magento\Framework\App\ObjectManager::getInstance(); // Instance of Object Manager
                $priceHelper = $objectManager->create('Magento\Framework\Pricing\Helper\Data'); // Instance of Pricing Helper
                $customPrice = $priceHelper->currency($customPrice, false, false);
            
                $customCalculatedPrice = round($this->rule->calcProductPriceRule($product,$customPrice));
                if($customCalculatedPrice){
                    $customPrice = $customCalculatedPrice;   
                }

                //$customPrice = round($customPrice);

                $item->setCustomPrice($customPrice);
                $item->setOriginalCustomPrice($customPrice);
                
            }
            $itemsOptions['finishOption'] = $finishOption;
            $itemsOptions['sizeOption'] = $sizeOption;

            $itemAllOptions = [];

            foreach ($itemsOptions as $itemsOption) {
                $itemAllOptions[] = $itemsOption;
            }

            $item->addOption(
                array(
                    'product' => $productId,
                    'code' => 'additional_options',
                    'value' => $this->serializer->serialize($itemAllOptions)
                )
            );
            $item->getProduct()->setIsSuperMode(true);

            $currencysymbol = $objectManager->get('Magento\Store\Model\StoreManagerInterface');
            $currency = $currencysymbol->getStore()->getCurrentCurrencyCode();

            $catalogSession = $objectManager->get('\Magento\Catalog\Model\Session');

            $candidates['value'] = $customPrice * $item->getProduct()->getQty();
            $candidates['product_id'] = $productId;
            $candidates['order_quantity'] = $item->getProduct()->getQty();
            $candidates['currency'] = $currency;
            $catalogSession->setPrestAddToCart($candidates);

            $logger->info(print_r($candidates, true)); 
        }/* end product type condition */
    }
}

3. For after submit quote and order place. Create events.xml file in app/code/[VendorName]/CustomModule/etc folder

<event name="sales_model_service_quote_submit_before">
    <observer name="ordercustomoption" instance="[VendorName]\CustomModule\Observer\OrderCustomOption" />
</event>

4. Create OrderCustomOption.php file on [VendorName]\CustomModule\Observer folder

<?php
namespace [VendorName]\CustomModule\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\Serialize\Serializer\Json;
use Magento\Framework\App\ObjectManager;

class OrderCustomOption implements ObserverInterface
{
    public function __construct(
    Json $serializer = null
    ) {
        $this->serializer = $serializer ?: ObjectManager::getInstance()->get(Json::class);
    }

    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        try {
            $quote = $observer->getQuote();
            $order = $observer->getOrder();
            $quoteItems = [];
 
            // Map Quote Item with Quote Item Id
            foreach ($quote->getAllVisibleItems() as $quoteItem) {
                $quoteItems[$quoteItem->getId()] = $quoteItem;
            }
 
            foreach ($order->getAllVisibleItems() as $orderItem) {
                $quoteItemId = $orderItem->getQuoteItemId();
                $quoteItem = $quoteItems[$quoteItemId];
                $additionalOptions = $quoteItem->getOptionByCode('additional_options');

                if(isset($additionalOptions)){
                    // Get Order Item's other options
                    $options = $orderItem->getProductOptions();
                    // Set additional options to Order Item
                    $options['additional_options'] = $this->serializer->unserialize($additionalOptions->getValue());
                    $orderItem->setProductOptions($options);
                }
            }
        } catch (\Exception $e) {
            echo $e->getMessage();
        }
    }

    
    private function getQuoteItemById($id)
    {
        if(empty($this->quoteItems))
        {
            /* @var  \Magento\Quote\Model\Quote\Item $item */
            foreach($this->quote->getItems() as $item)
            {
                //filter out config/bundle etc product
                if(!$item->getParentItemId() && $item->getProductType() == \Magento\Catalog\Model\Product\Type::TYPE_SIMPLE)
                {
                    $this->quoteItems[$item->getId()] = $item;
                }
            }
        }
        if(array_key_exists($id, $this->quoteItems))
        {
            return $this->quoteItems[$id];
        }
        return null;
    }
}