How to debug 'something went wrong' in magento2

Question

I installed magento2 2.2.10 version and installed custom modules. At begining it works finely after adding products , customers and place an order then it's not loading any admin grids(customers , sales , theme configuration , etc).

http://localhost/magento/admin/mui/index/render/key/384b4baacce8db392b425b6a0474d8572ba8651cb5a889f5be528b3546375ea6/?namespace=customer_listing&search=&filters%5Bplaceholder%5D=true&paging%5BpageSize%5D=20&paging%5Bcurrent%5D=1&sorting%5Bfield%5D=entity_id&sorting%5Bdirection%5D=asc&isAjax=true

This ajax call giving an error as below

SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 1 column 2648 of the JSON data

Then i removed all my custom modules and run the following commands

php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy -f
php bin/magento indexer:reindex

But no success to get the grid working again. How can i debug what will be the error in this case? Which module causing error?

I removed all var/report logs and refresh the page in admin but there is no error logs at all.

In my index.php file i placed below code as well. No error coming.

ini_set('error_reporting', E_ERROR);
register_shutdown_function("fatal_handler");
function fatal_handler() {
$error = error_get_last();
echo("<pre>");
print_r($error);
}

In google when i searched got suggestion as ui_bookmark table needs to be cleared . I did that as well its still not loading any customers , pages , blocks , orders etc. Please help me on this..

I tried a fresh install and it has no issues... After added my custom modules got issue but i removed them all still issue is there. How can i trace it?

Answer 1

You can trace the issues by creating your custom logger in your module. For example will share my module which I created for generating a custom log in my var folder.

After creating a basic module, create file:

/app/code/Magentoexample/Customlogger/Controller/Product/View.php

<?php

namespace Magentoexample\Customlogger\Controller\Product;

use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Psr\Log\LoggerInterface;

class View extends Action {

    /**
     * @var Psr\Log\LoggerInterface
     */
    private $logger;

    /**
     * @param Context $context
     * @param LoggerInterface $logger
     */
    public function __construct(
    Context $context, LoggerInterface $logger
    ) {
        $this->logger = $logger;
        parent::__construct($context);
    }

    /**
     * @return \Magento\Framework\Controller\Result\Json
     */
    public function execute() {
        $result = $this->resultJsonFactory->create();

        try {
            //your custom data handling logic....
        } catch (\Exception $e) {
            $this->logger->info($e->getMessage());
            return $result->setData(['success' => false, 'msg' => $e->getMessage()]);
        }
    }
}

/app/code/Magentoexample/Customlogger/etc/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <virtualType name="customLogger" type="Magento\Framework\Logger\Monolog">
        <arguments>
            <argument name="handlers" xsi:type="array">
                <item name="debug" xsi:type="object">Magentoexample\Customlogger\Logger\Handler\Custom</item>
            </argument>
        </arguments>
    </virtualType>

    <type name="Magentoexample\Customlogger\Controller\Product\View">
        <arguments>
            <argument name="logger" xsi:type="object">customLogger</argument>
        </arguments>
    </type>
</config>

/app/code/Magentoexample/Customlogger/Logger/Handler/Custom.php

<?php

namespace Magentoexample\Customlogger\Logger\Handler;

use Magento\Framework\Logger\Handler\Base;
use Monolog\Logger;

class Custom extends Base {

    protected $fileName = '/var/log/customlogger/exception.log';
    protected $loggerType = Logger::DEBUG;

}

Hope this helps you! If any queries then please do let me know.

Answer 2

you don't need to parse the returned data and use the following code-

json_data=data[0];
console.log(json_data[0]);

hope this will solve your issue