How to Get Weight Attribute in Totals Cart REST API Magento 2.X

Question

How Can i Get Weight Attribute in Cart REST API.

End Point: /rest/V1/carts/mine/

Response Default:

{
  "id": 8,
  "created_at": "2019-09-16 13:51:25",
  "updated_at": "2019-09-18 12:07:31",
  "is_active": true,
  "is_virtual": false,
  "items": [
    {
      "item_id": 7,
      "sku": "Test",
      "qty": 2,
      "name": "Test",
      "price": 100,
      "product_type": "simple",
      "quote_id": "8"
    },
    {
      "item_id": 8,
      "sku": "Test Bundle",
      "qty": 1,
      "name": "Test Bundle",
      "price": 200,
      "product_type": "bundle",
      "quote_id": "8"
    }
  ],
  "items_count": 2,
  "items_qty": 3,
  "customer": {
    "id": 4,
    "group_id": 1,
    "created_at": "2019-09-16 13:48:02",
    "updated_at": "2019-09-21 15:01:53",
    "created_in": "Default Store View",
    "email": "test@testmail.com",
    "firstname": "elantest",
    "lastname": "m",
    "store_id": 1,
    "website_id": 1,
    "addresses": [],
    "disable_auto_group_change": 0,
    "extension_attributes": {
      "is_subscribed": false
    },
    "custom_attributes": [
      {
        "attribute_code": "mobile_number",
        "value": "+910000000000"
      }
    ]
  },
  "billing_address": {
    "id": 248,
    "region": null,
    "region_id": null,
    "region_code": null,
    "country_id": null,
    "street": [
      ""
    ],
    "telephone": null,
    "postcode": null,
    "city": null,
    "firstname": null,
    "lastname": null,
    "customer_id": 4,
    "email": "test@testmail.com",
    "same_as_billing": 0,
    "save_in_address_book": 0
  },
  "orig_order_id": 0,
  "currency": {
    "global_currency_code": "INR",
    "base_currency_code": "INR",
    "store_currency_code": "INR",
    "quote_currency_code": "INR",
    "store_to_base_rate": 0,
    "store_to_quote_rate": 0,
    "base_to_global_rate": 1,
    "base_to_quote_rate": 1
  },
  "customer_is_guest": false,
  "customer_note_notify": true,
  "customer_tax_class_id": 3,
  "store_id": 1,
  "extension_attributes": {
    "shipping_assignments": [
      {
        "shipping": {
          "address": {
            "id": 53,
            "region": null,
            "region_id": null,
            "region_code": null,
            "country_id": null,
            "street": [
              ""
            ],
            "telephone": null,
            "postcode": null,
            "city": null,
            "firstname": null,
            "lastname": null,
            "customer_id": 4,
            "email": "test@testmail.com",
            "same_as_billing": 0,
            "save_in_address_book": 0
          },
          "method": null
        },
        "items": [
          {
            "item_id": 7,
            "sku": "Test",
            "qty": 2,
            "name": "Test",
            "price": 100,
            "product_type": "simple",
            "quote_id": "8"
          },
          {
            "item_id": 8,
            "sku": "Test Bundle",
            "qty": 1,
            "name": "Test Bundle",
            "price": 200,
            "product_type": "bundle",
            "quote_id": "8"
          }
        ]
      }
    ]
  }
}

I need to Get Weight Attribute for each item.

Answer 1

You can follow below solution to achieve this.

Vendor\Module\etc\extension_attributes.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd">
   <extension_attributes for="Magento\Quote\Api\Data\CartItemInterface">
      <attribute code="item_weight" type="float" />
   </extension_attributes>
</config>

Vendor\Module\etc\di.xml

<?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\Quote\Api\CartManagementInterface">
     <plugin name="set_item_weight" type="Vendor\Module\Plugin\QuoteItem"/>
  </type>
</config>

QuoteItem.php

namespace Vendor\Module\Plugin;
class QuoteItem {

    public function __construct(
      \Magento\Catalog\Api\ProductRepositoryInterfaceFactory $productRepository,
      \Magento\Quote\Api\Data\CartItemExtensionInterfaceFactory $cartItemExtensionFactory
    ){
       $this->productRepository = $productRepository;
       $this->cartItemExtension = $cartItemExtensionFactory;
    }

    public function afterGetCartForCustomer(\Magento\Quote\Api\CartManagementInterface $subject, $result)
    {
       foreach($result->getItems() as $item)
       {
          $product = $this->productRepository->create()->get($item->getSku());
          $extensionAttributes = $item->getExtensionAttributes();
          if ($extensionAttributes === null) {
             $extensionAttributes = $this->cartItemExtension->create();
          }
          $extensionAttributes->setItemWeight($product->getWeight());
          $item->setExtensionAttributes($extensionAttributes);
       } 
       return $result;  
    }
}

Let me know if you need further help. Happy Coding :)