How can I debug variables inside plugin?

Question

I tried die($some_var) and var_dump($some_var) but nothing happens.

DI:

<!-- di.xml -->
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">
 <type name="Magento\Quote\Model\Quote\Address">
 <plugin name="namespace.checkout.shipping" type="Namespace\Checkout\Plugin\Shipping" sortOrder="1" />
 </type>
</config>

Plugin:

<!-- Shipping.php -->
<?php
namespace Namespace\Checkout\Plugin;
use Magento\Framework\Exception\NoSuchEntityException;
use Magento\Quote\Model\Quote\Address;
use Magento\Quote\Model\Quote\Item;
use Magento\Quote\Model\Quote\Address\Rate;
use Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection;
use Magento\Catalog\Model\Product;
use Magento\Catalog\Model\ProductRepository;
use Namespace\Checkout\Helper\Data;
class Shipping
{
 private $productRepository;
 private $helper;
 public function __construct(ProductRepository $productRepository, Data $helper)
 {
 $this->productRepository = $productRepository;
 $this->helper = $helper;
 }
 public function afterGetShippingRatesCollection(Address $subject, AbstractCollection $rates)
 {
 $items = $subject->getQuote()->getItems();
 /* Something strange is happening here 
 0. If I just 'return $rates' without any conditions and custom code, It work perfectly. But I want to filter rates.
 1. When I add following code (if(!$items) { return $rates; }), it throws LocalizedException: "Please specify a shipping method" in vendor/magento/module-quote/Model/QuoteManagement.php(427)
 2. Without 'if(!$items){...}' I've got "Invalid argument supplied for foreach()" for second foreach in this function
 */
 if (!$items) { // there is a some strange magic, and I want it to debug.
 return $rates; 
 }
 /* end strange */
 /** @var Rate $rate */
 foreach ($rates->getItems() as $key => $rate) {
 /** @var Item $item */
 foreach ($items as $item) {
 try {
 /** @var Product $product */
 $product = $this->productRepository->get($item->getProduct()->getSku());
 } catch (NoSuchEntityException $e) {
 // product not found
 continue;
 }
 if (!$this->helper->isShippingRateAvailable($rate->getCode(),$product)) {
 $rates->removeItemByKey($key);
 continue 2;
 }
 }
 }
 return $rates;
 }
}

• Khoa Truong: Should try with XDebug with PHPStorm or Sublime Text.

Answer 1

Your plugin does not in list of interceptors. It does not work. To figure out why:

1. Go to generated code - generated folder or var\generation. It depends on Magento version.

2. Go to method \Magento\Quote\Model\Quote\Interceptor::getShippingRatesCollection() in the folder with generated code.

3. var_dump $pluginInfo variable. Your plugin should be in this array. If not - rerun setup:di:compile

• spiilmusic: actually DI have not been compiled due to errors

Answer 2

You try logging your variables

$writer = new \Zend\Log\Writer\Stream(BP . '/var/log/test.log');
$logger = new \Zend\Log\Logger();
$logger->addWriter($writer);
$logger->info($yourvariable);

• spiilmusic: For some reason it doesn't work