ErrorPageHandler

Introduction

The ErrorPageHandler class in JiFramework is responsible for rendering user-friendly error pages and JSON error responses when HTTP errors occur. It determines whether to display an HTML error page or a JSON response based on the client's request headers, making it suitable for both web applications and API endpoints.

This class follows the Singleton pattern to ensure only one instance is used throughout the application. It provides default error messages for common HTTP status codes but also allows custom messages to be displayed.

getInstance()

Method: getInstance(): ErrorPageHandler

Description: Retrieves the singleton instance of the ErrorPageHandler class. This ensures that the same instance is used throughout the application, following the Singleton design pattern.

Parameters: None

Returns: An instance of ErrorPageHandler.

Usage:

use JIFramework\Core\App\App;

// Initialize the App
$app = new App();

// Get the singleton instance
$errorPageHandler = $app->errorPageHandler;

OR

use JIFramework\Core\Error\ErrorPageHandler;

// Get the singleton instance
$errorPageHandler = ErrorPageHandler::getInstance();

Explanation:

  • The getInstance method checks if an instance already exists.
  • If not, it creates a new instance by calling the private constructor.
  • This pattern ensures that only one instance of ErrorPageHandler exists, promoting efficient resource usage.

handle()

Method: handle(int $errorCode, string $message = null): void

Description: Handles an HTTP error by setting the appropriate HTTP status code and rendering an error page or JSON response based on the client's request.

Parameters:

  • $errorCode (int): The HTTP status code representing the error (e.g., 404, 500).
  • $message (string, optional): A custom error message to display. If not provided, a default message corresponding to the status code is used.

Returns: void

Usage:

// Handle a 404 Not Found error
$errorPageHandler->handle(404);

// Handle a 500 Internal Server Error with a custom message
$errorPageHandler->handle(500, 'An unexpected error occurred. Please try again later.');

Explanation:

  • The handle method:
    • Sets the HTTP response code using http_response_code($errorCode).
    • Determines the appropriate error message to display:
      • If $message is provided, it uses that.
      • Otherwise, it looks up the default message for the provided $errorCode.
      • If no default message exists, it uses a generic message.
    • Checks if the client expects a JSON response by calling isJsonRequest().
      • If so, it calls renderJsonError() to output a JSON response.
      • Otherwise, it calls renderHtmlError() to display an HTML error page.
  • The method terminates the script execution using exit after rendering the error response to prevent any further output.

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