Mrthdrb

I want to add custom messages to my custom created attributes on the product page by using Block and Phtml.

My problem can be illustrated as following:

If not mistaken you can achieve it by adding custom input type in a module

first we need to add install script
Vendor/Module/Setup/InstallData.php :

class InstallData implements InstallDataInterface

 private $eavSetupFactory;


 public function __construct(EavSetupFactory $eavSetupFactory)
 
 $this->eavSetupFactory = $eavSetupFactory;
 

 public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
 
 $setup->startSetup();
 $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);
 $eavSetup->addAttribute(
 MagentoCatalogModelProduct::ENTITY,
 'attribute_id',
 [
 'type' => 'text',
 'backend' => '',
 'frontend' => 'VendorModuleBlockAdminhtmlProductCustomField',
 'label' => 'Custom attribute',
 'input' => 'text',
 'class' => '',
 'source' => '',
 'global' => 0,
 'visible' => true,
 'required' => false,
 'user_defined' => true,
 'default' => null,
 'searchable' => false,
 'filterable' => false,
 'comparable' => false,
 'visible_on_front' => false,
 'used_in_product_listing' => false,
 'unique' => false,
 'apply_to' => '',
 'system' => 1,
 'group' => 'General',
 ]
 );
 $setup->endSetup();
 

next we need to create our renderer for custom input:
Vendor/Module/Block/Adminhtml/Product/CustomField.php

namespace VendorModuleBlockAdminhtmlProduct;


use MagentoBackendBlockTemplateContext;
use MagentoConfigBlockSystemConfigFormField;
use MagentoFrameworkDataFormElementAbstractElement;

class CustomField extends Field

 public function __construct(
 Context $context,
 array $data = []
 ) 
 parent::__construct($context, $data);
 

 public function render(AbstractElement $element)
 
 $html = '';
 // you can modify your html output as you see fit. probably will work with parent::_decorateRowHtml but here you can see exactly how it's done.
 return $this->_decorateRowHtml($element, $html);
 

 public function _decorateRowHtml($element, $html)
 return '<tr id="row_' . $element->getHtmlId() . '">' . $html . '</tr>';
 

with this you can add javascript to watch for input change and if you need that text is loaded dynamic then you will need to add route and call your url.

Vendor/Module/etc/Adminhtml/routes.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
 <router id="admin">
 <route id="customattribute" frontName="customattribute">
 <module name="Vendor_Module" before="Magento_Adminhtml" />
 </route>
 </router>
</config> 

now we need to add controller:
Vendor/Module/Controller/Adminhtml/Catalog/Product/Dynamic.php

namespace VendorModuleControllerAdminhtmlCatalogProduct;

class Dynamic extends MagentoBackendAppAction


 public function __construct(
 MagentoBackendAppActionContext $context,
 ) 
 parent::__construct($context);
 
 public function execute()
 // do what is needed and output your html with echo
 

so if you need to call your url you can add following to render function CustomField.php:

$html.="<script>
require([
 'jquery',
 'prototype',
], function(jQuery)
 function do_something() 

 new Ajax.Request('".$this->getUrl('customattribute/catalog/product/dynamic')."', 
 loaderArea: true,
 asynchronous: true,
 parameters: params,
 onSuccess: function(transport) 
 //do something with output
 return true;
 
 );
 

 jQuery('my_input').change(function () 
 do_something();
 );
);
</script>";