与其他中间件一起使用entomb/slim-json-api

我对PHP比较陌生，这可能是这里的主要问题——我感觉我错过了一些PHP内部的基本原理，这些基本原理要么使解决这个问题变得直截了当，要么使我明显地知道为什么我在浪费时间!…

基本上在下面的Slim API代码中，我希望由优秀的entomb/Slim -json- API中间件添加的异常处理也适用于随后的myMiddleware。如下所示，它似乎只处理路由代码中产生的故障…

(PHP v 5.4.17)

$ php composer.phar info
entomb/slim-json-api dev-master c11e001 Slim extension to implement fast JSON API's
slim/slim            2.6.2              Slim Framework, a PHP micro framework

require 'vendor/autoload.php';
use Slim'Middleware;
class myMiddleware extends Middleware
{
    public function call()
    {
        $uri_array = explode('/', $this->app->request->getResourceUri());
        $env = $this->app->environment;
        if($uri_array[2] == 98) {
            throw new 'Exception("User $uri_array[2], you are not even welcome in middleware!");
        } else {
            $body = array('user_from_middleware' => $uri_array[2]);
            $env['slim.input'] = json_encode($body);
        }
        $this->next->call();
    }
}
///////////////////////////////////////////////////////////////////////////////////
$app = new 'Slim'Slim();
$app->view(new 'JsonApiView());
$app->add(new 'JsonApiMiddleware());
$app->add(new myMiddleware());
$app->get('/user/:id', function($id) use ($app) {
    if ($id == 99) {
        throw new 'Exception("User $id, you are not welcome!");
    } else {
        $body = json_decode($app->request->getBody());
        $body->msg = "User $id welcome to my API!";
        $app->render(200,(array) $body);
    }
});

下面是一个忽略了两个exception的请求:

$ curl http://localhost:8082/test.php/user/1
{"user_from_middleware":"1","msg":"User 1 welcome to my API!","error":false,"status":200}

…这个在路由中触发Exception，显示jsonapimmiddleware正在工作:

$ curl http://localhost:8082/test.php/user/99
{"msg":"ERROR: User 99, you are not welcome!","error":true,"status":500}

…但是当这个在myMiddleware中触发Exception时，API什么也不返回:

$ curl http://localhost:8082/test.php/user/98
$

…我可以从日志中看到异常确实被抛出了:

[Mon Nov  7 21:54:08 2016] PHP Fatal error:  Uncaught exception 'Exception' with message 'User 98, you are not even welcome in middleware!' in /path/to/test.php:14
Stack trace:
#0 /path/to/vendor/slim/slim/Slim/Slim.php(1302): myMiddleware->call()
#1 /path/to/test.php(42): Slim'Slim->run()
#2 {main}
  thrown in /path/to/test.php on line 14

我错过了什么?如果这是一个乏味的问题，再次道歉。