How can i remove object manager from my code of Magento 2

Question

I don't want to use object manager, how can i change my code?
In the past, i have used method cart $cart but it is deprecated

     <?php

     namespace Custom\ShippingMethod\Model\Carrier;

 use Magento\Quote\Model\Quote\Address\RateRequest;
 use Magento\Shipping\Model\Carrier\AbstractCarrier;
 use Magento\Shipping\Model\Carrier\CarrierInterface;
 use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\Quote\Model\Quote\Address\RateResult\ErrorFactory;
 use Psr\Log\LoggerInterface;
 use Magento\Shipping\Model\Rate\ResultFactory;
 use Magento\Quote\Model\Quote\Address\RateResult\MethodFactory;
 use Magento\Framework\ObjectManagerInterface;


 class PlanetExpress extends AbstractCarrier implements CarrierInterface
{

protected $_code = 'planetexpress';

protected $rateResultFactory;

protected $rateMethodFactory;

protected $_objectManager;

public function __construct(
    ObjectManagerInterface $objectManager,
    ScopeConfigInterface $scopeConfig,
    ErrorFactory $rateErrorFactory,
    LoggerInterface $logger,
    ResultFactory $rateResultFactory,
    MethodFactory $rateMethodFactory,
    array $data = []
)
{
    $this->_objectManager = $objectManager;
    $this->rateResultFactory = $rateResultFactory;
    $this->rateMethodFactory = $rateMethodFactory;
    parent::__construct($scopeConfig, $rateErrorFactory, $logger, $data);
}

public function getAllowedMethods()
{
    return ['planetexpress' => $this->getConfigData('name')];
}

public function collectRates(RateRequest $request)
{
    if (!$this->getConfigFlag('active')) {
        return false;
    }

    /** @var \Magento\Shipping\Model\Rate\Result $result */
    $result = $this->rateResultFactory->create();

    /** @var \Magento\Quote\Model\Quote\Address\RateResult\Method $method */
    $method = $this->rateMethodFactory->create();
    $method->setCarrier($this->_code);
    $method->setCarrierTitle($this->getConfigData('title'));

    $method->setMethod($this->_code);
    $method->setMethodTitle($this->getConfigData('name'));


    $cart = $this->_objectManager->get('\Magento\Checkout\Model\Cart');

    $uniqueItems = $cart->getQuote()->getItemsCount();
    $totalItems = $cart->getQuote()->getItemsQty();
    $subTotal = $cart->getQuote()->getGrandTotal();

    $amount = $this->getConfigData('price');

    $countryRate = 1;
    if ($request->getDestCountryId() == 'US'){
        $countryRate = 3;
    }elseif ($request->getDestCountryId() == 'UA'){
        $countryRate = 2;
    }elseif ($request->getDestCountryId() == 'CA'){
        $countryRate = 7;
    }

        $shippingPrice = ($subTotal * $uniqueItems * $amount) / $totalItems * $countryRate;

    $method->setPrice($shippingPrice);
    $method->setCost($amount);

    $result->append($method);

    return $result;
}

}

Answer 1

Try below code

<?php

namespace Custom\ShippingMethod\Model\Carrier;

use Magento\Quote\Model\Quote\Address\RateRequest;
use Magento\Shipping\Model\Carrier\AbstractCarrier;
use Magento\Shipping\Model\Carrier\CarrierInterface;
use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Quote\Model\Quote\Address\RateResult\ErrorFactory;
use Psr\Log\LoggerInterface;
use Magento\Shipping\Model\Rate\ResultFactory;
use Magento\Quote\Model\Quote\Address\RateResult\MethodFactory;
use Magento\Checkout\Model\Cart;

class PlanetExpress extends AbstractCarrier implements CarrierInterface
{

    protected $_code = 'planetexpress';

    protected $rateResultFactory;

    protected $rateMethodFactory;

    protected $cartRepository;

    public function __construct(
        Cart $cart,
        ScopeConfigInterface $scopeConfig,
        ErrorFactory $rateErrorFactory,
        LoggerInterface $logger,
        ResultFactory $rateResultFactory,
        MethodFactory $rateMethodFactory,
        array $data = []
    )
    {
        $this->cart = $cart;
        $this->rateResultFactory = $rateResultFactory;
        $this->rateMethodFactory = $rateMethodFactory;
        parent::__construct($scopeConfig, $rateErrorFactory, $logger, $data);
    }

    public function getAllowedMethods()
    {
        return ['planetexpress' => $this->getConfigData('name')];
    }

    public function collectRates(RateRequest $request)
    {
        if (!$this->getConfigFlag('active')) {
            return false;
        }

        /** @var \Magento\Shipping\Model\Rate\Result $result */
        $result = $this->rateResultFactory->create();

        /** @var \Magento\Quote\Model\Quote\Address\RateResult\Method $method */
        $method = $this->rateMethodFactory->create();
        $method->setCarrier($this->_code);
        $method->setCarrierTitle($this->getConfigData('title'));

        $method->setMethod($this->_code);
        $method->setMethodTitle($this->getConfigData('name'));

        $uniqueItems = $this->cart->getQuote()->getItemsCount();
        $totalItems = $this->cart->getQuote()->getItemsQty();
        $subTotal = $this->cart->getQuote()->getGrandTotal();

        $amount = $this->getConfigData('price');

        $countryRate = 1;
        if ($request->getDestCountryId() == 'US'){
            $countryRate = 3;
        }elseif ($request->getDestCountryId() == 'UA'){
            $countryRate = 2;
        }elseif ($request->getDestCountryId() == 'CA'){
            $countryRate = 7;
        }

            $shippingPrice = ($subTotal * $uniqueItems * $amount) / $totalItems * $countryRate;

        $method->setPrice($shippingPrice);
        $method->setCost($amount);

        $result->append($method);

        return $result;
    }
}

Answer 2

i try to use helper and this code good for me.

i take quote by checkoutHelper

<?php

namespace Custom\ShippingMethod\Model\Carrier;

use Magento\Quote\Model\Quote\Address\RateRequest;
use Magento\Shipping\Model\Carrier\AbstractCarrier;
use Magento\Shipping\Model\Carrier\CarrierInterface;
use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Quote\Model\Quote\Address\RateResult\ErrorFactory;
use Psr\Log\LoggerInterface;
use Magento\Shipping\Model\Rate\ResultFactory;
use Magento\Quote\Model\Quote\Address\RateResult\MethodFactory;
use Magento\Framework\ObjectManagerInterface;


class PlanetExpress extends AbstractCarrier implements CarrierInterface
{

protected $_code = 'planetexpress';

protected $rateResultFactory;

protected $rateMethodFactory;

protected $_objectManager;

protected $checkoutHelper;

public function __construct(
    \Magento\Checkout\Helper\Data $checkoutHelper,
    ObjectManagerInterface $objectManager,
    ScopeConfigInterface $scopeConfig,
    ErrorFactory $rateErrorFactory,
    LoggerInterface $logger,
    ResultFactory $rateResultFactory,
    MethodFactory $rateMethodFactory,
    array $data = []
)
{
    $this->_objectManager = $objectManager;
    $this->checkoutHelper = $checkoutHelper;
    $this->rateResultFactory = $rateResultFactory;
    $this->rateMethodFactory = $rateMethodFactory;
    parent::__construct($scopeConfig, $rateErrorFactory, $logger, $data);
}

public function getAllowedMethods()
{
    return ['planetexpress' => $this->getConfigData('name')];
}

public function collectRates(RateRequest $request)
{
    if (!$this->getConfigFlag('active')) {
        return false;
    }

    /** @var \Magento\Shipping\Model\Rate\Result $result */
    $result = $this->rateResultFactory->create();

    /** @var \Magento\Quote\Model\Quote\Address\RateResult\Method $method */
    $method = $this->rateMethodFactory->create();
    $method->setCarrier($this->_code);
    $method->setCarrierTitle($this->getConfigData('title'));

    $method->setMethod($this->_code);
    $method->setMethodTitle($this->getConfigData('name'));


    $checkoutHelper = $this->checkoutHelper->getQuote();

    $uniqueItems = $checkoutHelper->getItemsCount();
    $totalItems = $checkoutHelper->getItemsQty();
    $subTotal = $checkoutHelper->getSubtotal();

    $amount = $this->getConfigData('price');

    $countryRate = 1;
    if ($request->getDestCountryId() == 'US'){
        $countryRate = 3;
    }elseif ($request->getDestCountryId() == 'UA'){
        $countryRate = 2;
    }elseif ($request->getDestCountryId() == 'CA'){
        $countryRate = 7;
    }

        $shippingPrice = ($subTotal * $uniqueItems * $amount) / $totalItems * $countryRate;

    $method->setPrice($shippingPrice);
    $method->setCost($amount);

    $result->append($method);

    return $result;
}

}