How to add phtml file at edit tab of Magento 2 custom module in admin?

Question

I have created a custom module. When we click on the admin grid to edit, it opens edit page. In that I am showing tabs. When I click on that tab I need to show template file. If you see the below screen you can get idea

this is my tab file

    <?php
/**
  /**
 * Exinent_Customerids Module 
 *
 * @category    customer
 * @package    
 * @author      pawan
 *
 */

namespace Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab;

/**
 * customerid post edit form main tab
 */
use Magento\Backend\Block\Template\Context;
use Magento\Framework\Registry;

class Meat extends \Magento\Backend\Block\Template
{
//    const IBAN_TEMPLATE = 'Exinent_Customerids::test.phtml';
     protected $_template = 'test.phtml';
    protected $_coreRegistry = null;

//   public function __construct(
//        \Magento\Backend\Block\Widget\Context $context,
//        array $data = []
//    ) {
//        parent::__construct($context, $data);
//    }

//   protected function _prepareLayout()
//    {
//        parent::_prepareLayout();
//        if (!$this->getTemplate()) {
//            $this->setTemplate(static::IBAN_TEMPLATE);
//        }
//
//        return $this;
//    }
}

my layout file

<block class="Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab\Meat" name="customerids_customerids_edit_tab_meat"/>
                <arguments>
                    <argument name="config" xsi:type="array">
                        <item name="label" xsi:type="string" translate="true">customerids_customerids_edit_tab_meat</item>
                        <item name="collapsible" xsi:type="boolean">true</item>
                        <item name="opened" xsi:type="boolean">true</item>
                        <item name="sortOrder" xsi:type="string">2</item>
                        <item name="canShow" xsi:type="boolean">true</item>
                        <item name="componentType" xsi:type="string">fieldset</item>
                    </argument>
                </arguments>

Answer 1

1. You need to confirm that, you create test.phtml file at this location.
   Vendor\Modulename\view\adminhtml\templates\test.phtml

2. You need to replace _prepareLayout function code like this.

   <?php
   namespace Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab;
   
   use Magento\Backend\Block\Template\Context;
   use Magento\Framework\Registry;
   
   class Meat extends \Magento\Backend\Block\Template
   {
   
     protected function _prepareLayout()
     {
         $customhtml = parent::_prepareLayout();
         $customhtml .= $this->setTemplate('Vendor_Modulename::test.phtml')->toHtml();
         return $customhtml;
     }
   }
   

Answer 2

1.In the layout file you can add the code :

<referenceContainer name="left">
    <block class="Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab" name="customerids_customerids_edit_tab">
        <block class="Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab\Child" name="customerids_customerids_edit_tab_child"/>                           
        <action method="addTab">
            <argument name="name" xsi:type="string">child_section</argument>
            <argument name="block" xsi:type="string">customerids_customerids_edit_tab_child</argument>
        </action>               
    </block>
</referenceContainer>

2.Create the new file on the path :

Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab\Child.php

With content :

namespace Vendor\Modulename\Block\Adminhtml\Customerids\Edit\Tab;

class Child extends \Magento\Backend\Block\Widget\Form\Generic implements \Magento\Backend\Block\Widget\Tab\TabInterface
{
    /**
     * @var \Magento\Backend\Block\Widget\Form\Renderer\Fieldset
     */
    protected $_rendererFieldset;
    /**
     * @var \Magento\Store\Model\System\Store
     */
    protected $_systemStore;
    protected $_customerFactory;    
    protected $_resource;   

    /**
     * @param \Magento\Backend\Block\Template\Context $context
     * @param \Magento\Framework\Registry $registry
     * @param \Magento\Framework\Data\FormFactory $formFactory
     * @param \Magento\Store\Model\System\Store $systemStore
     * @param array $data
     */
    public function __construct(
        \Magento\Backend\Block\Template\Context $context,
        \Magento\Framework\Registry $registry,
        \Magento\Framework\Data\FormFactory $formFactory,
        \Magento\Store\Model\System\Store $systemStore,
        \Magento\Backend\Block\Widget\Form\Renderer\Fieldset $rendererFieldset,
        \Magento\Customer\Model\CustomerFactory $customerFactory,   
        \Magento\Framework\App\ResourceConnection $resource,  
        array $data = []
    ) {
        $this->_systemStore = $systemStore;
        $this->_rendererFieldset = $rendererFieldset;
        $this->_customerFactory = $customerFactory;  
        $this->_resource = $resource;  
        parent::__construct($context, $registry, $formFactory, $data);
    }

    /**
     * Prepare form
     *
     * @return $this
     */
    protected function _prepareForm()
    {
        /* @var $model \Magefan\Blog\Model\Category */
        $model = $this->_coreRegistry->registry('current_model');

        /*
         * Checking if user have permissions to save information
         */
        $isElementDisabled = !$this->_isAllowedAction('Vendor_Modulename::child');

        /** @var \Magento\Framework\Data\Form $form */
        $form = $this->_formFactory->create();

        $form->setHtmlIdPrefix('child_');

        $fieldset = $form->addFieldset('base_fieldset', ['legend' => __('Add Your Child')]);

        if ($model->getId()) {
            $fieldset->addField('id', 'hidden', ['name' => 'id']);
        }

        $fieldset->addField(
            'html', 
            'text', 
            [
                'name' => 'html',
                'label' => __('Html Content'),
                'title' => __('Html Content'),
                'required' => true,
                'disabled' => $isElementDisabled                 
            ]
        )->setRenderer($this->_rendererFieldset->setTemplate('Vendor_Modulename::child.phtml'));   

        if (!$model->getId()) {
            $model->setData('status', $isElementDisabled ? '0' : '1');
        }                       
        $this->_eventManager->dispatch('vendor_modulename_edit_tab_main_prepare_form', ['form' => $form]);

        $form->setValues($model->getData());
        $this->setForm($form);

        return parent::_prepareForm();
    }

    /**
     * Prepare label for tab
     *
     * @return \Magento\Framework\Phrase
     */
    public function getTabLabel()
    {
        return __('Html Content');
    }

    /**
     * Prepare title for tab
     *
     * @return \Magento\Framework\Phrase
     */
    public function getTabTitle()
    {
        return __('Html Content');
    }

    /**
     * Returns status flag about this tab can be shown or not
     *
     * @return bool
     */
    public function canShowTab()
    {
        return true;
    }

    /**
     * Returns status flag about this tab hidden or not
     *
     * @return bool
     */
    public function isHidden()
    {
        return false;
    }

    /**
     * Check permission for passed action
     *
     * @param string $resourceId
     * @return bool
     */
    protected function _isAllowedAction($resourceId)
    {
        return $this->_authorization->isAllowed($resourceId);
    }
}

3.Create file :

Vendor/Modulename/view/adminhtml/templates/child.phtml

And put your content here

Hope it helps !