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How do you implement a custom error handling strategy in Slim Framework?

How do you implement a custom error handling strategy in Slim Framework?

To implement a custom error handling strategy in Slim Framework, follow these minimal steps:

1. Set Up Slim Framework

Make sure you have Slim Framework installed.

Example

composer require slim/slim

2. Create a Custom Error Handler

Define a custom error handler class that extends \Psr\Http\Message\ResponseInterface.

Example

<?php
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Slim\Factory\AppFactory;

class CustomErrorHandler
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, \Throwable $exception): ResponseInterface
    {
        // Set the response status code
        $statusCode = $exception->getCode() ?: 500;

        // Create the response body
        $response->getBody()->write(json_encode([
            'error' => [
                'message' => $exception->getMessage(),
                'code' => $statusCode,
            ]
        ]));

        // Set content type to application/json
        return $response->withHeader('Content-Type', 'application/json')
                        ->withStatus($statusCode);
    }
}
?>

3. Register the Custom Error Handler

In your Slim application setup, register the custom error handler.

Example

<?php
$app = AppFactory::create();

// Register the custom error handler
$app->setErrorHandler(new CustomErrorHandler());
?>

4. Define Routes and Throw Errors

Set up your routes, and throw exceptions as needed to test the error handler.

Example

<?php
$app->get('/example', function ($request, $response) {
    throw new \Exception("This is a custom error message", 400); // Example error
});
?>

5. Run the Application

Finally, run your Slim application.

Example

<?php
$app->run();
?>

Summary Code Example

Here’s a concise example of the complete custom error handling implementation:

Example

<?php
require 'vendor/autoload.php';

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Slim\Factory\AppFactory;

class CustomErrorHandler
{
    public function __invoke(ServerRequestInterface $request, ResponseInterface $response, \Throwable $exception): ResponseInterface
    {
        $statusCode = $exception->getCode() ?: 500;
        $response->getBody()->write(json_encode([
            'error' => [
                'message' => $exception->getMessage(),
                'code' => $statusCode,
            ]
        ]));
        return $response->withHeader('Content-Type', 'application/json')
                        ->withStatus($statusCode);
    }
}

$app = AppFactory::create();
$app->setErrorHandler(new CustomErrorHandler());

$app->get('/example', function ($request, $response) {
    throw new \Exception("This is a custom error message", 400);
});

$app->run();
?>

How do you implement a custom error handling strategy in Slim Framework?

1. Set Up Slim Framework

Example

2. Create a Custom Error Handler

Example

3. Register the Custom Error Handler

Example

4. Define Routes and Throw Errors

Example

5. Run the Application

Example

Summary Code Example

Example

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