Magento 2 custom shipping method carrier is not showing after selecting the method from dropdown in order shipment backend

Question

I have installed my Shipping Tracker module in Magento 2.3.5p1, I have added a custom Shipping method which is showing in the dropdown in the backend on the Order shipment page as below,

Note: This issue is only on Magento 2.3.5p1, it's working fine for Magento 2.3.4

After selecting the custom shipping method, the carrier is showing Custom Value instead of the Shiprocket1, Although it is showing for default methods. Check below screenshot,

You can check the inspect element in the below screenshot so you can have more idea,

Here is the code for adding a custom shipping method to dropdown,

Vendor/Shippingtracker/etc/adminhtml/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\Shipping\Block\Adminhtml\Order\Tracking">
        <plugin name="carrier_options_backend_shipment" type="Vendor\Shippingtracker\Plugin\Block\Adminhtml\Order\Tracking" sortOrder="5" />
    </type>
</config>

Vendor/Shippingtracker/Plugin/Block/Adminhtml/Order/Tracking.php

<?php
 
namespace Vendor\Shippingtracker\Plugin\Block\Adminhtml\Order;

class Tracking
{
    public function __construct(
        \Vendor\Shippingtracker\Helper\Data $shippingTrackerHelper
    ) {
        $this->shippingTrackerHelper = $shippingTrackerHelper;
    }

    
    public function afterGetCarriers(\Magento\Shipping\Block\Adminhtml\Order\Tracking $subject, $result)
    {
        $customCarrier = $this->shippingTrackerHelper->getCustomCarrierTitle();
        if (!empty($customCarrier)) {
            foreach ($customCarrier as $code => $carrierTitle) {
                $result[$code] = $carrierTitle;
            }
        }
        return $result;
    }
}

Helper Method getCustomCarrierTitle()

public function getCustomCarrierTitle()
    {
        $j = 15;
        $customCarrier = [];
        for ($i=1; $i <= $j; $i++) {
            $enable = 'shippingtracker_section/custom_shippingtracker_'.$i.'/custom_shippingtracker_enable_'.$i;
            $Title = 'shippingtracker_section/custom_shippingtracker_'.$i.'/custom_shippingtracker_title_'.$i;
            $carrierEnable = $this->getConfigValue($enable);
            $carrierTitle = $this->getConfigValue($Title);
            if ($carrierEnable) { 
                if ($carrierTitle) {
                    $customCarrier['customcarrier'.$i] = $carrierTitle;
                }
            }
        }
        return $customCarrier;
    }

System.xml for $enable and $Title

<group id="custom_shippingtracker_1" translate="label" type="text" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>Custom Shipping Tracker 1</label>
                    <field id="custom_shippingtracker_enable_1" translate="label" type="select" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                        <label>Enable</label>
                        <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                    </field>  
                    <field id="custom_shippingtracker_title_1" translate="label" type="text" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                        <label>Method Title</label>
                        <validate>required-entry</validate>
                        <depends>
                            <field id="shippingtracker_section/custom_shippingtracker_1/custom_shippingtracker_enable_1">1</field>
                        </depends>
                    </field>
                    <field id="custom_shippingtracker_url_1" translate="label" type="text" sortOrder="1" showInDefault="1" showInWebsite="1" showInStore="1">
                        <label>Url</label>
                        <validate>required-entry</validate>
                        <comment>
                            <![CDATA[replace the TrackingNumber to {{tracking_code}},<br/> example:<br/><strong>"http://www.example.com?trackingNumber=#TRACKINGNUMBER#"</strong> To <br/><strong>"http://www.example.com?TrackingNumber={{tracking_code}}"</strong>]]>
                        </comment>
                        <depends>
                            <field id="shippingtracker_section/custom_shippingtracker_1/custom_shippingtracker_enable_1">1</field>
                        </depends>
                    </field>    
            </group>

I have also tried overriding the \Magento\Shipping\Block\Adminhtml\Order\Tracking class, but I don't see my custom shipping method in the dropdown so I don't think that's working as well.

Any help would be appreciated.

Answer 1

Without seeing your config.xml, I believe Magento is failing to create a Carrier object, thus returning 'Custom Value' as a fallback title:

\Magento\Rma\Block\Adminhtml\Rma\Edit\Tab\General\Shipping\Tracking

public function getCarrierTitle($code)
    {
        $carrier = $this->_carrierFactory->create($code);
        return $carrier ? $carrier->getConfigData('title') : __('Custom Value');
    }

So why can't Magento create the Carrier object? Well, Magento attempts to create it from config, and returns false if it can't get a value:

\Magento\Shipping\Model\CarrierFactory

public function get($carrierCode)
    {
        $className = $this->_scopeConfig->getValue(
            'carriers/' . $carrierCode . '/model',
            \Magento\Store\Model\ScopeInterface::SCOPE_STORE
        );
        if (!$className) {
            return false;
        }
        // operations if configuration value is found
    }

The next question, then, is twofold: (1) where is the carrier configured, and (2) what values does Magento need? Note that Magento is specifically looking for a model value at a carriers/{carrier_code}/model location. Here's how Magento does this for the UPS carrier:

vendor/magento/module-ups/etc/config.xml

<default>
        <carriers>
        <ups>
            <!-- some values -->
            <title>United Parcel Service</title>
            <model>Magento\Ups\Model\Carrier</model>
            <!-- more values -->
        </ups>
    </carriers>
</default>

So Magento is looking for a valid model class name that the ObjectManager can use to create the carrier object, from which Magento can then extract the carrier's title. If there's no such class or no such config value, then object creation will abort and your shipping method title will default to 'Custom Value.'

If this is your problem, then this should be enough to get you started. Adobe has a good tutorial for creating a custom shipping carrier which should help you ensure you've created and configured your carrier correctly.

Answer 2

Finally, I found the answer by overriding this class Magento\Shipping\Block\Adminhtml\Order\Tracking\View

etc/di.xml

<preference for="Magento\Shipping\Block\Adminhtml\Order\Tracking\View" type="Vendor\Shippingtracker\Block\Adminhtml\Order\Tracking\View" />

Vendor/Shippingtracker/Block/Adminhtml/Order/Tracking/View.php

<?php
 
namespace Vendor\Shippingtracker\Block\Adminhtml\Order\Tracking;

class View extends \Magento\Shipping\Block\Adminhtml\Order\Tracking\View
{
    /**
      * @var \Magento\Shipping\Model\CarrierFactory
      */
    protected $_carrierFactory;

    /**
     * @param \Magento\Backend\Block\Template\Context $context
     * @param \Magento\Shipping\Model\Config $shippingConfig
     * @param \Magento\Framework\Registry $registry
     * @param \Magento\Shipping\Model\CarrierFactory $carrierFactory
     * @param \Vendor\Shippingtracker\Helper\Data $shippingTrackerHelper
     * @param array $data
     */
    public function __construct(
        \Magento\Backend\Block\Template\Context $context,
        \Magento\Shipping\Model\Config $shippingConfig,
        \Magento\Framework\Registry $registry,
        \Magento\Shipping\Model\CarrierFactory $carrierFactory,
        \Vendor\Shippingtracker\Helper\Data $shippingTrackerHelper,
        array $data = []
    ) {
        $this->_carrierFactory = $carrierFactory;
        $this->shippingTrackerHelper = $shippingTrackerHelper;
        parent::__construct(
            $context,
            $shippingConfig,
            $registry,
            $carrierFactory,
            $data
        );
    }

    /**
     * Get carrier title
     *
     * @param string $code
     *
     * @return \Magento\Framework\Phrase|string|bool
     */
    public function getCarrierTitle($code)
    {
        $enable = $this->shippingTrackerHelper->getConfigValue('shippingtracker_section/shippingtracker_general/shippingtracker_enable');
        if ($enable) {
            $customCarrier = $this->shippingTrackerHelper->getCustomCarrierTitle();
            if (!empty($customCarrier)) {
                foreach ($customCarrier as $carrierCode => $carrierTitle) {
                    if ($code == $carrierCode) {
                        return $carrierTitle;
                    }
                }
            }
        }
        
        $carrier = $this->_carrierFactory->create($code);
        return $carrier ? $carrier->getConfigData('title') : __('Custom Value');
    }
}

Hope it helps someone.