php - 返回错误，以便js承诺捕获

Question

Is that even possible to return some kind of error (ie using header()) from php file that is received by ajax call and reveived as error (via catch method?)

consider such a php (example doesnt work correctly):

<?php 

session_start();

$_SESSION['user_id'] = 1;

 header("Access-Control-Allow-Origin: *");
 header("Access-Control-Allow-Credentials: true");
 header("Access-Control-Allow-Methods: GET,HEAD,OPTIONS,POST,PUT");
 header("Access-Control-Allow-Headers: Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");



if ( $_SESSION['user_id'] == 0 ) {
        header('Content-Type: application/json');
        print json_encode(["test" => 123]);
    }
else
    {
       header('HTTP/1.1 1337 Internal Server Kalreg');
       header('Content-Type: application/json; charset=UTF-8');
        die(json_encode(array('message' => 'ERROR', 'code' => 1337)));
}
?>

and js:

axios.get('loginStatus.php', { crossDomain: true })
        .then(function (response) {
        console.log(response);
        })
        .catch(function (error) {
          console.log(error);
        });


    }
  }

Now because $_SESSION['user_id'] is set to 1 server error is generated, and because of that catch in js should react in proper way. In fact it is not - in chrome-dev-tools i get an error:

xhr.js?ec6c:178 OPTIONS http://192.168.0.15/game/src/server/loginStatus.php 500 (Internal Server Error) Failed to load http://192.168.0.15/game/src/server/loginStatus.php: Response for preflight has invalid HTTP status code 500.

Is that possible? Or should i return just JSON file with error or not and manage it with .then not .catch?

Kalreg.

Answer 1

If you want catch to be executed and this is decided on server-side, then you will need to set an unsuccessful status code via http_response_code. A status code of 417 (Expectation failed) seems to be a good pick in your case, but you can see here what you can pick from.