M2.2: On the admin side, when an admin modifies the price, how to get warning message what if he set price below $100

Question

When an admin is about to modify the price and save the modification, he should get warning message which he should set a price over $100 and it must not be saved what if he set the price below $100.

Is there any basic function on Magento? Or i can use Observer in admin page.

Please give me an idea for this.

Thank you

Answer 1

I am assuming you know how to create basic module in magento2, here I am giving you an idea.

You need to create event.xml file in below path

app\code\YOUR_NAMESPACE\YOURMODULE\etc\adminhtml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="catalog_product_save_after">
        <observer name="test_name" instance="YOUR_NAMESPACE\YOUR_MODULENAME\Observer\Productsaveafter" />
    </event>
</config>

Now create your observer file Productsaveafter.php at below path -

app\code\YOUR_NAMESPACE\YOURMODULE\Observer\

namespace YOURNAMESPACE\YOURMODULENAME\Observer;

use Magento\Framework\Event\ObserverInterface;

class Productsaveafter implements ObserverInterface
{    
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $_product = $observer->getProduct();  // you will get product object
        $price = $_product->getPrice(); // will get price
        if($price < 100)
        {
           // put your logic here
        }
    }   
}

Answer 2

Thanks to @Shashank Kumrawat.

This is my code

app\code\YOUR_NAMESPACE\YOUR_MODULE\etc\adminhtml\event.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">

   <event name="catalog_product_save_after">
       <observer name="productsaveafter" instance="YOUR_NAMESPACE\YOUR_MODULE\Observer\Productsaveafter" />
   </event>


</config>

app\code\YOUR_NAMESPACE\YOUR_MODULE\Observer\Productsaveafter.php

namespace YOUR_NAMESPACE\YOUR_MODULE\Observer;

class Productsaveafter implements \Magento\Framework\Event\ObserverInterface
{
  public function execute(\Magento\Framework\Event\Observer $observer)
  {
    $_product = $observer->getProduct();  // you will get product object
    $producType = $_product->getTypeId();
    $price = $_product->getPrice(); // will get price

    if($_producType=="simple" && $price < 100)
        {

            throw new \Magento\Framework\Exception\CouldNotDeleteException(__("Prices have been changed below 100!"));
        }

     return $this;
  }
}