Slim 3中的自定义错误处理程序无法正常工作

Question

I want to override the default error handlers in Slim 3 and respond with JSON instead of the default HTML page. But I can't get it to work, my custom handlers are ignored completely and I can't figure out why.

My project structure looks like this:

api/
  public/
    index.php
  src/
    config/
      database.php
      handlers.php
      settings.php
    models/
      product.php
    routes/
      products.php

My index.php looks like this:

<?php

use Psr\Http\Message\ServerRequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;

require __DIR__ . '/../vendor/autoload.php';
require __DIR__ . '/../src/config/database.php';

// Instantiate the app
$settings = require __DIR__ . '/../src/config/settings.php';
$app = new \Slim\App(['settings' => $settings]);

// Set up handlers
$container = $app->getContainer();
require __DIR__ . "/../src/config/handlers.php";

// Register routes
require __DIR__ . '/../src/routes/products.php';

// Run app
$app->run();

And my handlers.php file with all the custom error handlers looks like this:

<?php 

/**
 * Custom global error handler.
 */
$container['errorHandler'] = function($container) {
  return function ($request, $response, $exception) use ($container) {
      return $response->withStatus(500)
          ->withHeader('Content-Type', 'application/json')
          ->write(json_encode(array(
              'error' => 'INTERNAL_ERROR',
              'error_message' => 'Something went wrong internally.',
              'status_code' => '500',
              'trace' => $exception.getTraceAsString()
            ), JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT));    
  };
};

/**
* Custom global PHP error handler.
*/
$container['phpErrorHandler'] = function($container) {
  return $container['errorHandler'];
};

/**
* Custom 404 Not Found error handler.
*/
$container['notFoundHandler'] = function($container) {
  return function ($request, $response) use ($container) {
      return $response->withStatus(404)
          ->withHeader('Content-Type', 'application/json')
          ->write(json_encode(array(
              'error' => 'NOT_FOUND',
              'error_message' => 'Endpoint was not found. Check API documentation for valid endpoints.',
              'status_code' => '404',
            ), JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT));    
  };
};

/**
* Custom 405 Not Allowed error handler.
*/
$container['notAllowedHandler'] = function($container) {
  return function ($request, $response, $methods) use ($container) {
      return $response->withStatus(405)
          ->withHeader('Allow', implode(', ', $methods))
          ->withHeader('Content-Type', 'application/json')
          ->write(json_encode(array(
              'error' => 'NOT_ALLOWED',
              'error_message' => 'HTTP request method is not allowed. Method must be of: ' . implode(', ', $methods),
              'status_code' => '405',
            ), JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT));    
  };
};

What I have tried so far:

• Adding all handlers before creating $app and loading the $container into it.
• Unset the existing handler before creating a custom one, like so: unset($app->getContainer()['notFoundHandler']);

I just can't wrap my head around what goes wrong and why I am still getting the default HTML views when an error is thrown.

Answer 1

Thanks to @Nima I figured out that I had accidentally created a new instance of the $app = new \Slim\App; inside my products.php file. Removing that got it to work.