Magento 2 Save custom customer address attribute in customer edit form using extension attributes

Question

I want to save custom customer address attribute in Customer Edit Form under My Account section. I have created an attribute using Setup script and save that attribute using extension attributes.

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\Customer\Api\Data\AddressInterface">
 <attribute code="city_id" type="string"/>
 </extension_attributes>
</config>

Here I couldn't extend Magento\Customer\Api\Data\AddressInterface, that's why I'm using extension_attributes. Then I created a plugin to get and set that attribute value as follows:

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\Customer\Api\AddressRepositoryInterface">
 <plugin name="customer_city_id" type="Vendor\Module\Plugin\CustomerCity"/>
 </type>
</config>

Vendor/Module/Plugin/CustomerCity.php

<?php
namespace Vendor\Module\Plugin;
use Magento\Customer\Api\Data\AddressInterface;
class CustomerCity {
 public function afterGetById(
 \Magento\Customer\Api\AddressRepositoryInterface $subject,
 $address,
 $addressId
 ) {
 try {
 if ($address->getExtensionAttributes() === null) {
 $address->setExtensionAttributes($this->extensionAttributeFactory->create(AddressInterface::class));
 }
 $extensionAttribute = $address->getExtensionAttributes();
 $extensionAttribute->setCityId(
 ($address->getCustomAttribute('city_id')) ?
 $address->getCustomAttribute('city_id')->getValue() : ""
 );
 $address->setExtensionAttributes($extensionAttribute);
 }
 catch (\Exception $e) {
 // Don't handle exceptions
 }
 return $address;
 }
}

Unfortunately, I'm getting an error We can't save the address. As I printed an exception message, I'm getting this message: Class string does not exist.

Please anyone let me know what I'm doing wrong. Thanks in anticipation.

• Shoaib Munir: Did you find solution on this?
• Shoaib Munir: Please share here if you find any solution magento.stackexchange.com/questions/279458/…