Php 我们使用Slim框架运行restful API时出现未捕获异常

我想为我的android应用程序创建一个使用Slim的API。API非常简单，我只想在我的数据库中保存一篇文章的数据。我的代码如下所示

<?php

error_reporting(-1);
ini_set('display_errors', 'On');

require_once '../include/DbHandler.php';
require '.././libs/Slim/Slim.php';

\Slim\Slim::registerAutoloader();
$app = new \Slim\Slim();

/**
 * Verifying required params posted or not
 */
function verifyRequiredParams($required_fields) {
    $error = false;
    $error_fields = "";
    $request_params = array();
    $request_params = $_REQUEST;
    if ($_SERVER['REQUEST_METHOD'] == 'PUT') {
        $app = \Slim\Slim::getInstance();
        parse_str($app->request()->getBody(), $request_params);
    }
    foreach ($required_fields as $field) {
        if (!isset($request_params[$field]) || strlen(trim($request_params[$field])) <= 0) {
            $error = true;
            $error_fields .= $field . ', ';
        }
    }
    if ($error) {
        $response = array();
        $app = \Slim\Slim::getInstance();
        $response["error"] = true;
        $response["message"] = 'Required field(s) ' . substr($error_fields, 0, -2) . ' is missing or empty';
        echoRespnse(400, $response);
        $app->stop();
    }
}

/**
 * Echoing json response to client
 * @param String $status_code Http response code
 * @param Int $response Json response
 */
function echoRespnse($status_code, $response) {
    $app = \Slim\Slim::getInstance();
    $app->status($status_code);
    $app->contentType('application/json');
    echo json_encode($response);
}


/**
 * Creating new task in db
 * method POST
 * params - name
 * url - /articles/
 * 
 * {"error": false,
    "message": "Task created successfully",
    "task_id": 1}
 */
$app->post('/articles', 'authenticate', function() use ($app) {
            //verifyRequiredParams(array('article'));

            $response = array();
            $article_image = $app->request->post('article_image');
            $article_video = $app->request->post('article_video');
            $article_title = $app->request->post('article_title');
            $article_main_body = $app->request->post('article_main_body');
            $article_tags = $app->request->post('article_tags');
            $db = new DbHandler();

            // creating new article
            $article_id = $db->createTask($article_image,$article_video,$article_title,$article_main_body,$article_tags);

            if ($article_id != NULL) {
                $response["error"] = false;
                $response["message"] = "Article created successfully";
                $response["article_id"] = $article_id;
            } else {
                $response["error"] = true;
                $response["message"] = "Failed to create article. Please try again";
            }
            echoRespnse(201, $response);
        });     

/**
 * Listing all articles
 * method GET
 * url /articles    
 * {
    "error": false,
    "tasks": [
        {
            "id": 1,
            "task": "Complete REST article by Sunday",
            "status": 0,
            "createdAt": "2014-01-08 23:35:45"
        },
        {
            "id": 2,
            "task": "Book bus tickets!",
            "status": 0,
            "createdAt": "2014-01-08 23:56:52"
        }
    ]
}      
 */

$app->get('/articles', 'authenticate', function() {
            $response = array();
            $db = new DbHandler();

            $result = $db->getAllTasks();

            $response["error"] = false;
            $response["articles"] = array();

            // looping through result and preparing articles array
            while ($article = $result->fetch_assoc()) {
                $tmp = array();
                $tmp["id"] = $task["id"];
                $tmp["article_image"] = $article["article_image"];
                $tmp["article_video"] = $article["article_video"];
                $tmp["article_title"] = $article["article_title"];
                $tmp["article_main_body"] = $article["article_main_body"];
                $tmp["article_tags"] = $article["article_tags"];
                $tmp["created_at"] = $article["created_at"];
                array_push($response["articles"], $tmp);
            }

            echoRespnse(200, $response);
        });     

/**
 * Listing single task of particual user
 * method GET
 * url /articles/:id
 * Will return 404 if the task doesn't belongs to user
 * 
 * {
    "error": false,
    "id": 2,
    "task": "Book bus tickets!",
    "status": 0,
    "createdAt": "2014-01-08 23:56:52"
    }
 */

$app->get('/articles/:id', 'authenticate', function($article_id) {
            $response = array();
            $db = new DbHandler();
            // fetch article
            $result = $db->getArticle($article_id);

            if ($result != NULL) {
                $response["error"] = false;
                $response["id"] = $result["id"];
                $response["article_image"] = $result["article_image"];
                $response["article_video"] = $result["article_video"];
                $response["article_title"] = $result["article_title"];
                $response["article_main_body"] = $result["article_main_body"];
                $response["article_tags"] = $result["article_tags"];
                $response["created_at"] = $result["created_at"];
                echoRespnse(200, $response);
            } else {
                $response["error"] = true;
                $response["message"] = "The requested resource doesn't exists";
                echoRespnse(404, $response);
            }
        });

$app->run(); 
?>

我的项目结构是

include
  |
   -Config.php
   -DbConnect.php
   -DbHandler.php
libs
  |
   -Slim
v1
  |
   -.htaccess
   -index.php

我在DigitalOcean中创建的Ubuntu Droplet中上传了我的项目，但是当我运行我的项目时，我得到了下面的异常

未捕获异常“InvalidArgumentException”所有路由中间件必须可调用

---

我的服务器配置文档中有什么需要更改的吗？

Slim正在尝试调用一个不存在的函数

在每个路由定义中，都有一个值为

'authenticate'

的第二个参数（例如在

$app->post（'/articles'，'authenticate'，function（）中使用（$app）{}）；

在执行以下操作之前，必须在某个位置定义

authenticate

函数：

function authenticate() {
  echo "My authenticate logic!";
}

---

请查看。

Slim正在尝试调用一个不存在的函数

在每个路由定义中，都有一个值为

'authenticate'

的第二个参数（例如在

$app->post（'/articles'，'authenticate'，function（）中使用（$app）{}）；

在执行以下操作之前，必须在某个位置定义

authenticate

函数：

function authenticate() {
  echo "My authenticate logic!";
}

请看下面的图片