show a custom attribute instead of full name if customer logged in M2

Question

I want to display in top menu my custom attribute instead of full name customer, I tried to override customer.phtml under design my theme but no result please any help

    <? 
    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    $customerRepositoryInterface = $objectManager->create('\Magento\Customer\Api\CustomerRepositoryInterface');
    $customerSession = $objectManager->create('Magento\Customer\Model\Session');
    if($customerSession->isLoggedIn()) {
        $customerId = $customerSession->getCustomer()->getId();
        $customeratt = $customerRepositoryInterface->getById($customerId);
        $customAttributeCode = 'custom_name';
        echo $cattrValue = $customeratt->getCustomAttribute($customAttributeCode); //Please echo this line when you want display custom name.
    }
?>

now i can't find my top menu here is the code of default.xml under my theme `

and here is the code of my default.phtml under customer_module under my theme

  <referenceBlock name="customer-account-navigation-billing-agreements-link" remove="true"/>

    <!-- Product review link -->
    <referenceBlock name="customer-account-navigation-product-reviews-link" remove="true"/>

    <!-- My credit card link -->
    <referenceBlock name="customer-account-navigation-my-credit-cards-link" remove="true"/>

    <!-- Account link -->
    <referenceBlock name="customer-account-navigation-account-link" remove="true"/>

    <!-- Account edit link -->
    <referenceBlock name="customer-account-navigation-account-edit-link" remove="true"/>


    <!-- Orders link -->

   <!-- <referenceBlock name="customer-account-navigation-orders-link" remove="true"/>

-->

    <!-- Wish list link -->
    <referenceBlock name="customer-account-navigation-wish-list-link" remove="true"/>
    <referenceBlock name="top.links">
        <referenceBlock name="register-link" remove="true" />           <!--for Create Account Link-->
        <referenceBlock name="authorization-link" remove="true" />      <!--for Sign In Link  -->
        <referenceBlock name="wish-list-link" remove="true" />          <!--for WishList Link-->
    </referenceBlock>


    <referenceBlock name="header">
        <arguments>
            <argument name="show_part" xsi:type="string">other</argument>
        </arguments>
    </referenceBlock>

    <move element="authorization-link" destination="header-wrapper" after="minicart"/>
    <referenceBlock name="reviews.tab" remove="true" />
    <referenceBlock name="product.review.form" remove="true" />
    <referenceBlock name="product.info.review" remove="true" />
    <referenceBlock name="product.info.details" remove="true"></referenceBlock>
    <referenceBlock name="catalog.compare.sidebar" remove="true"/>
    <referenceBlock name="view.addto.compare" remove="true" />
    <referenceBlock name="view.addto.wishlist" remove="true" />




<?xml version="1.0"?>

        <block class="Magento\Customer\Block\Account\AuthorizationLink" name="authorization-link-login" template="account/link/authorization.phtml"/>
    </referenceBlock>
    <block class="Magento\Theme\Block\Html\Header" name="header" as="header">

        <arguments>
            <argument name="show_part" xsi:type="string">welcome</argument>
        </arguments>
    </block>
    <move element="header" destination="header.links" before="-"/>
    <move element="register-link" destination="header.links"/>

    <move element="top.links" destination="customer"/>


    <move element="authorization-link" destination="top.links" after="-"/>

</body>

Answer 1

try this below code

<?php 
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$customerSession = $objectManager->get('Magento\Customer\Model\Session');
if($customerSession->isLoggedIn()) {
    $customerId = $customerSession->getCustomer()->getId(); 
    $customerRepository = $objectManager->get('Magento\Customer\Api\CustomerRepositoryInterface');
    $customer = $customerRepository->getById($customerId);
    $cattrValue = $customer->getCustomAttribute('my_custom_attribute')->getValue();

}

?>