PHP: Slim Framework Exception Handling

James Okpe George picture James Okpe George · Jan 16, 2016 · Viewed 8.4k times · Source

I just finished creating an API application with slim framework, initially, in my code I use a dependency container to handle all exceptions thrown, the code is below.

//Add container to handle all exceptions/errors, fail safe and return json
$container['errorHandler'] = function ($container) {
    return function ($request, $response, $exception) use ($container) {
        //Format of exception to return
        $data = [
            'message' => $exception->getMessage()
        ];
        return $container->get('response')->withStatus(500)
            ->withHeader('Content-Type', 'application/json')
            ->write(json_encode($data));
    };
};

But instead of throwing a 500 Server Error all the time I would like to add other HTTPS reponse code. I wonder if I could get help on how to go about that.

public static function decodeToken($token)
{
    $token = trim($token);
    //Check to ensure token is not empty or invalid
    if ($token === '' || $token === null || empty($token)) {
        throw new JWTException('Invalid Token');
    }
    //Remove Bearer if present
    $token = trim(str_replace('Bearer ', '', $token));

    //Decode token
    $token = JWT::decode($token, getenv('SECRET_KEY'), array('HS256'));

    //Ensure JIT is present
    if ($token->jit == null || $token->jit == "") {
        throw new JWTException('Invalid Token');
    }

    //Ensure User Id is present
    if ($token->data->uid == null || $token->data->uid == "") {
        throw new JWTException("Invalid Token");
    }
    return $token;
}

The problem is even more from functions like the above one, since slim framework decides to handle all exceptions implicitly, I have no access to use try catch to catch any errors

Answer

Hassan Althaf picture Hassan Althaf · Jan 16, 2016

Not that hard, it is simple. Rewrite the code:

container['errorHandler'] = function ($container) {
    return function ($request, $response, $exception) use ($container) {
        //Format of exception to return
        $data = [
            'message' => $exception->getMessage()
        ];
        return $container->get('response')->withStatus($response->getStatus())
            ->withHeader('Content-Type', 'application/json')
            ->write(json_encode($data));
    };
}

So what does this code do? You basically pass a $response as before, and what this code does is that it gets the status code from the $response object and passes it to the withStatus() method.

Slim Documentation for referring to status.