介绍
在本文的前一部分中，我们提出了一种所谓的社会决策支持系统架构。一方面，该系统包括一个MetaTrader5客户机，用于向服务器发送EA的自动决策。在通信的另一端，有一个基于瘦PHP框架的twitter（twitter）应用程序，它接收事务信号并将其存储在MySQL数据库中，最后将其发布给相关人员。SDSS的主要目的是记录可手动执行的自动交易信号，并手动做出相应的决策。这是可能的，因为自动交易信号可以以这种方式呈现给大量的专业观众。
在第二部分中，我们打算使用MQL5编程语言来开发SDSS客户机。我们还将讨论替代方案，以确定它们的优点和缺点。最后，我们将组装所有拼图拼图块，并完成phpsrestapi的成形，以接收来自ea的事务信号。要做到这一点，我们必须研究客户端编程的一些方面。
现在您可以释放您的MQL5交易信号！
1。SDSS客户机
1.1。在Ontimer事件中发布交易信号
我研究了显示来自Ontimer事件的事务信号的简单问题。在看到这个简单的例子是如何工作的之后，很容易推断出它的核心行为。
dummy-ontimer.mq5：
#property copyright "Author: laplacianlab, CC Attribution-Noncommercial-No Derivate 3.0" #property link "https://www.mql5.com/en/users/laplacianlab" #property version "1.00" #property description "Simple REST client built on the OnTimer event for learning purposes." int OnInit() { EventSetTimer(10); return(0); } void OnDeinit(const int reason) { } void OnTimer() { //--- REST client's HTTP vars string uri="http://api.laplacianlab.com/signal/add"; char post[]; char result[]; string headers; int res; string signal = "id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&"; StringToCharArray(signal,post); //--- reset last error ResetLastError(); //--- post data to REST API res=WebRequest("POST",uri,NULL,NULL,50,post,ArraySize(post),result,headers); //--- check errors if(res==-1) { Print("Error code =",GetLastError()); //--- maybe the URL is not added, show message to add it MessageBox("Add address '"+uri+"' in Expert Advisors tab of the Options window","Error",MB_ICONINFORMATION); } else { //--- successful Print("REST client's POST: ",signal); Print("Server response: ",CharArrayToString(result,0,-1)); } }
如您所见，这个客户机应用程序的中心部分是mql5的新函数webrequest。
编写一个定制的MQL5控件来处理HTTP通信是另一种选择，但是将此任务委托给metaquote的新语言功能将更安全。
上述MQL5程序的输出如下：
OR 0 15:43:45.363 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
KK 0 15:43:45.365 RESTClient (EURUSD,H1) Server response: {"id_ea":"1","symbol":"AUDUSD","operation":"BUY","value":"0.9281","id":77}
PD 0 15:43:54.579 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
CE 0 15:43:54.579 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
ME 0 15:44:04.172 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
JD 0 15:44:04.172 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
NE 0 15:44:14.129 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
ID 0 15:44:14.129 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
NR 0 15:44:24.175 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
IG 0 15:44:24.175 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
MR 0 15:44:34.162 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
JG 0 15:44:34.162 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
PR 0 15:44:44.179 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
CG 0 15:44:44.179 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
HS 0 15:44:54.787 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
KJ 0 15:44:54.787 RESTClient (EURUSD,H1) Server response: {"id_ea":"1","symbol":"AUDUSD","operation":"BUY","value":"0.9281","id":78}
DE 0 15:45:04.163 RESTClient (EURUSD,H1) REST client's POST: id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&
OD 0 15:45:04.163 RESTClient (EURUSD,H1) Server response: {"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
请注意，服务器的响应消息：
{"status": "ok", "message": {"text": "Please wait until the time window has elapsed."}}
这是因为API方法中实现了一个小的安全机制，以防止高频头皮剥离自动访问SDS。
/** * REST method. * Adds and tweets a new trading signal. */ $app->post('/signal/add', function() { $tweeterer = new Tweeterer(); // This condition is a simple mechanism to prevent hyperactive scalpers if ($tweeterer->canTweet($tweeterer->getLastSignal(1)->created_at, '1 minute')) { $signal = (object)($_POST); $signal->id = $tweeterer->addSignal(1, $signal); $tokens = $tweeterer->getTokens(1); $connection = new TwitterOAuth( API_KEY, API_SECRET, $tokens->access_token, $tokens->access_token_secret); $connection->host = "https://api.twitter.com/1.1/"; $ea = new EA(); $message = "{$ea->get($signal->id_ea)->name} on $signal->symbol. $signal->operation at $signal->value"; $connection->post('statuses/update', array('status' => $message)); echo '{"status": "ok", "message": {"text": "Signal processed."}}'; } });
在Web应用程序中，在Web服务器检查传入的HTTP请求是否为恶意请求（例如，传入的信号不是拒绝服务攻击）之后调用这些简单机制。
Web服务器负责防止此类攻击。例如，Apache可以通过避免和组合安全模块来阻止它们。
典型的Apache模块mod回避配置允许服务器管理员控制应用程序每秒接收HTTP请求的次数，以此类推。
<IfModule mod_evasive20.c> DOSHashTableSize 3097 DOSPageCount 2 DOSSiteCount 50 DOSPageInterval 1 DOSSiteInterval 1 DOSBlockingPeriod 60 DOSEmailNotify someone@somewhere.com </IfModule>
因此，正如我们所说，这个php cantweet方法的目的是防止高频头皮剥离，即将其视为对sds的HTTP攻击。cantweet方法在twetter类中实现（稍后讨论）：
/** * Checks if it's been long enough so that the tweeterer can tweet again * @param string $timeLastTweet e.g. 2014-07-05 15:26:49 * @param string $timeWindow A time window, e.g. 1 hour * @return boolean */ public function canTweet($timeLastTweet=null, $timeWindow=null) { if(!isset($timeLastTweet)) return true; $diff = time() - strtotime($timeLastTweet); switch($timeWindow) { case '1 minute'; $diff <= 60 ? $canTweet = false : $canTweet = true; break; case '1 hour'; $diff <= 3600 ? $canTweet = false : $canTweet = true; break; case '1 day': $diff <= 86400 ? $canTweet = false : $canTweet = true; break; default: $canTweet = false; break; } if($canTweet) { return true; } else { throw new Exception('Please wait until the time window has elapsed.'); } }
现在，让我们看看webrequest自动为我们构建的HTTP请求的头字段：
Content-Type: application/x-www-form-urlencoded Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*
webrequest的post方法假定程序员打算发送HTML表单数据，但在这种情况下，我们希望将以下HTTP请求头字段发送到服务器：
Content-Type: application/json Accept: application/json
没有魔法子弹。我们必须考虑我们的决定，学习如何使webrequest适应我们的需要，并找出优缺点。
从技术角度来看，建立一个真正的HTTP REST会话更为正确，但是我们要说的是，一个更安全的解决方案是通过metaquote委托HTTP会话，尽管webrequest（）似乎旨在访问网页，而不是Web服务。正是因为这个原因，我们最终用一个URL对客户的交易信号进行编码。API将接收URL编码的信号，并将其转换为PHP的stdclass格式。
WebRequest（）函数的另一种选择是使用wininet.dll库来编写工作在接近操作系统级别的自定义MQL5控件。本文使用wininet.dll通过Internet在终端之间进行数据交换（使用wininet.dll通过Internet在终端之间交换数据），并使用mql5中的wininet（使用mql5中的wininet）。第二部分：邮政请求和文件解释了这种方法的基本原理。然而，mql5开发人员和mql5社区的经验表明，该解决方案并不像乍一看那样简单。它的缺点是调用wininet函数可能会受到metatrader升级的影响。
1.2。发布EA交易信号
现在让我们来推断一下最新的解释。我创建了以下虚拟自动化事务来说明与头皮控制和拒绝服务攻击相关的问题。
Dimy.MQ5:
//+------------------------------------------------------------------+ //| Dummy.mq5 | //| Copyright © 2014, Jordi Bassagañas | //+------------------------------------------------------------------+ #property copyright "Author: laplacianlab, CC Attribution-Noncommercial-No Derivate 3.0" #property link "https://www.mql5.com/en/users/laplacianlab" #property version "1.00" #property description "Dummy REST client (for learning purposes)." //+------------------------------------------------------------------+ //| Trade class | //+------------------------------------------------------------------+ #include <Trade/Trade.mqh> //+------------------------------------------------------------------+ //| Declaration of variables | //+------------------------------------------------------------------+ CPositionInfo PositionInfo; CTrade trade; MqlTick tick; int stopLoss = 20; int takeProfit = 20; double size = 0.1; //+------------------------------------------------------------------+ //| Tweet trading signal | //+------------------------------------------------------------------+ void Tweet(string uri, string signal) { char post[]; char result[]; string headers; int res; StringToCharArray(signal,post); //--- reset last error ResetLastError(); //--- post data to REST API res=WebRequest("POST",uri,NULL,NULL,50,post,ArraySize(post),result,headers); //--- check errors if(res==-1) { //--- error Print("Error code =",GetLastError()); } else { //--- successful Print("REST client's POST: ",signal); Print("Server response: ",CharArrayToString(result,0,-1)); } } //+------------------------------------------------------------------+ //| Expert initialization function | //+------------------------------------------------------------------+ int OnInit() { return(0); } //+------------------------------------------------------------------+ //| Expert deinitialization function | //+------------------------------------------------------------------+ void OnDeinit(const int reason) { } //+------------------------------------------------------------------+ //| Expert tick function | //+------------------------------------------------------------------+ void OnTick() { //--- update tick SymbolInfoTick(_Symbol, tick); //--- calculate Take Profit and Stop Loss levels double tp; double sl; sl = tick.ask + stopLoss * _Point; tp = tick.bid - takeProfit * _Point; //--- open position trade.PositionOpen(_Symbol,ORDER_TYPE_SELL,size,tick.bid,sl,tp); //--- trade URL-encoded signal "id_ea=1&symbol=AUDUSD&operation=BUY&value=0.9281&"; string signal = "id_ea=1&symbol=" + _Symbol + "&operation=SELL&value=" + (string)tick.bid + "&"; Tweet("http://api.laplacianlab.com/signal/add",signal); }
以上代码不能再简化了。这个EA在每个即时报价中都有一个空头头寸。出于这个原因，这个自动事务与在短时间间隔内放置许多头寸非常相似，特别是在频繁振荡中运行一段时间之后。没必要为此担心。服务器端可以通过两种方式控制发布间隔，一种是通过配置Web服务器来防止DOS攻击，另一种是在PHP应用程序中定义一个确定的时间窗口，如前面所述。
整理完所有这些之后，您现在可以将发布功能添加到您最喜欢的EA中。
1.3。用户如何看到他们的交易信号？
在下面的示例中，@laplacianlab允许SDSS发布在前面章节中发布的虚拟EA信号：
图1.@拉普拉西亚拉布已经允许SDSS公布他的代表
顺便说一下，在这个例子中出现了brinbart的名称，因为这是我们在本文第一部分中存储在mysql数据库中的数据之一。id_ea=1与“brin belt”相关，但我们将其更改为“dummy”以匹配解释。无论如何，这是一个小方面，但对于由此带来的不便，我深表歉意。
mysql数据库最终如下：
# MySQL database creation...
CREATE DATABASE IF NOT EXISTS laplacianlab_com_sdss;
use laplacianlab_com_sdss;
CREATE TABLE IF NOT EXISTS twitterers (
id mediumint UNSIGNED NOT NULL AUTO_INCREMENT,
twitter_id VARCHAR(255),
access_token TEXT,
access_token_secret TEXT,
created_at TIMESTAMP NOT NULL DEFAULT NOW(),
PRIMARY KEY (id)
) ENGINE=InnoDB;
CREATE TABLE IF NOT EXISTS eas (
id mediumint UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(32),
description TEXT,
created_at TIMESTAMP NOT NULL DEFAULT NOW(),
PRIMARY KEY (id)
) ENGINE=InnoDB;
CREATE TABLE IF NOT EXISTS signals (
id int UNSIGNED NOT NULL AUTO_INCREMENT,
id_ea mediumint UNSIGNED NOT NULL,
id_twitterer mediumint UNSIGNED NOT NULL,
symbol VARCHAR(10) NOT NULL,
operation VARCHAR(6) NOT NULL,
value DECIMAL(9,5) NOT NULL,
created_at TIMESTAMP NOT NULL DEFAULT NOW(),
PRIMARY KEY (id),
FOREIGN KEY (id_ea) REFERENCES eas(id),
FOREIGN KEY (id_twitterer) REFERENCES twitterers(id)
) ENGINE=InnoDB;
# Dump some sample data...
# As explained in Part I, there's one single twitterer
INSERT INTO eas(name, description) VALUES
('Bollinger Bands', '<p>Robot based on Bollinger Bands. Works with H4 charts.</p>'),
('Two EMA', '<p>Robot based on the crossing of two MA. Works with H4 charts.</p>');
2。SDS的服务器端
在继续构建我们的社会决策支持系统的服务器端之前，让我们简单记住，此时我们有以下目录结构：
图2。基于瘦PHP API的目录结构
2.1。PHP API代码
根据我们的解释，index.php文件如下所示：
<?php /** * Laplacianlab's SDSS - A REST API for tweeting MQL5 trading signals * * @author Jordi Bassagañas * @copyright 2014 Jordi Bassagañas * @link https://www.mql5.com/en/users/laplacianlab */ /* Bootstrap logic */ require_once 'config/config.php'; set_include_path(get_include_path() . PATH_SEPARATOR . APPLICATION_PATH . '/vendor/'); set_include_path(get_include_path() . PATH_SEPARATOR . APPLICATION_PATH . '/model/'); require_once 'slim/slim/Slim/Slim.php'; require_once 'abraham/twitteroauth/twitteroauth/twitteroauth.php'; require_once 'Tweeterer.php'; require_once 'EA.php'; session_start(); /* Init Slim */ use /Slim/Slim; Slim::registerAutoloader(); $app = new Slim(array('debug' => false)); $app->response->headers->set('Content-Type', 'application/json'); /** * Slim's exception handler */ $app->error(function(Exception $e) use ($app) { echo '{"status": "error", "message": {"text": "' . $e->getMessage() . '"}}'; }); /** * REST method. * Custom 404 error. */ $app->notFound(function () use ($app) { echo '{"status": "error 404", "message": {"text": "Not found."}}'; }); /** * REST method. * Home page. */ $app->get('/', function () { echo '{"status": "ok", "message": {"text": "Service available, please check API."}}'; }); /** * REST method. * Adds and tweets a new trading signal. */ $app->post('/signal/add', function() { $tweeterer = new Tweeterer(); // This condition is a simple mechanism to prevent hyperactive scalpers if ($tweeterer->canTweet($tweeterer->getLastSignal(1)->created_at, '1 minute')) { $signal = (object)($_POST); $signal->id = $tweeterer->addSignal(1, $signal); $tokens = $tweeterer->getTokens(1); $connection = new TwitterOAuth( API_KEY, API_SECRET, $tokens->access_token, $tokens->access_token_secret); $connection->host = "https://api.twitter.com/1.1/"; $ea = new EA(); $message = "{$ea->get($signal->id_ea)->name} on $signal->symbol. $signal->operation at $signal->value"; $connection->post('statuses/update', array('status' => $message)); echo '{"status": "ok", "message": {"text": "Signal processed."}}'; } }); /** * REST implementation with TwitterOAuth. * Gives permissions to Laplacianlab's SDSS to tweet on the user's behalf. * Please, visit https://github.com/abraham/twitteroauth */ $app->get('/tweet-signals', function() use ($app) { if (empty($_SESSION['twitter']['access_token']) || empty($_SESSION['twitter']['access_token_secret'])) { $connection = new TwitterOAuth(API_KEY, API_SECRET); $request_token = $connection->getRequestToken(OAUTH_CALLBACK); if ($request_token) { $_SESSION['twitter'] = array( 'request_token' => $request_token['oauth_token'], 'request_token_secret' => $request_token['oauth_token_secret'] ); switch ($connection->http_code) { case 200: $url = $connection->getAuthorizeURL($request_token['oauth_token']); // redirect to Twitter $app->redirect($url); break; default: throw new Exception('Connection with Twitter failed.'); break; } } else { throw new Exception('Error Receiving Request Token.'); } } else { echo '{"status": "ok", "message": {"text": "Laplacianlab/'s SDSS can ' . 'now access your Twitter account on your behalf. Please, if you no ' . 'longer want this, log in your Twitter account and revoke access."}}'; } }); /** * REST implementation with TwitterOAuth. * This is the OAuth callback of the method above. * Stores the access tokens into the database. * Please, visit https://github.com/abraham/twitteroauth */ $app->get('/twitter/oauth_callback', function() use ($app) { if(isset($_GET['oauth_token'])) { $connection = new TwitterOAuth( API_KEY, API_SECRET, $_SESSION['twitter']['request_token'], $_SESSION['twitter']['request_token_secret']); $access_token = $connection->getAccessToken($_REQUEST['oauth_verifier']); if($access_token) { $connection = new TwitterOAuth( API_KEY, API_SECRET, $access_token['oauth_token'], $access_token['oauth_token_secret']); // Set Twitter API version to 1.1. $connection->host = "https://api.twitter.com/1.1/"; $params = array('include_entities' => 'false'); $content = $connection->get('account/verify_credentials', $params); if($content && isset($content->screen_name) && isset($content->name)) { $tweeterer = new Tweeterer(); $data = (object)array( 'twitter_id' => $content->id, 'access_token' => $access_token['oauth_token'], 'access_token_secret' => $access_token['oauth_token_secret']); $tweeterer->exists($content->id) ?$tweeterer->update($data) : $tweeterer->create($data); echo '{"status": "ok", "message": {"text": "Laplacianlab/'s SDSS can ' . 'now access your Twitter account on your behalf. Please, if you no ' . 'longer want this, log in your Twitter account and revoke access."}}'; session_destroy(); } else { throw new Exception('Login error.'); } } } else { throw new Exception('Login error.'); } }); /** * Run Slim! */ $app->run();
2.2。面向对象编程封装器
我们现在必须创建php类tweeterer。PHP和EA。php在瘦应用程序的模块目录中。注意，我们只将MySQL数据表封装在一个简单的面向对象类中，而不开发实际的模块层。
型号/tweeterer.php：
<?php require_once 'DBConnection.php'; /** * Tweeterer's simple OOP wrapper * * @author Jordi Bassagañas * @copyright 2014 Jordi Bassagañas * @link https://www.mql5.com/en/users/laplacianlab */ class Tweeterer { /** * @var string MySQL table */ protected $table = 'twitterers'; /** * Gets the user's OAuth tokens * @param integer $id * @return stdClass OAuth tokens: access_token and access_token_secret */ public function getTokens($id) { $sql = "SELECT access_token, access_token_secret FROM $this->table WHERE id=$id"; return DBConnection::getInstance()->query($sql)->fetch_object(); } /** * Checks if it's been long enough so that the tweeterer can tweet again * @param string $timeLastTweet e.g. 2014-07-05 15:26:49 * @param string $timeWindow A time window, e.g. 1 hour * @return boolean */ public function canTweet($timeLastTweet=null, $timeWindow=null) { if(!isset($timeLastTweet)) return true; $diff = time() - strtotime($timeLastTweet); switch($timeWindow) { case '1 minute'; $diff <= 60 ? $canTweet = false : $canTweet = true; break; case '1 hour'; $diff <= 3600 ? $canTweet = false : $canTweet = true; break; case '1 day': $diff <= 86400 ? $canTweet = false : $canTweet = true; break; default: $canTweet = false; break; } if($canTweet) { return true; } else { throw new Exception('Please wait until the time window has elapsed.'); } } /** * Adds a new signal * @param type $id_twitterer * @param stdClass $data * @return integer The new row id */ public function addSignal($id_twitterer, stdClass $data) { $sql = 'INSERT INTO signals(id_ea, id_twitterer, symbol, operation, value) VALUES (' . $data->id_ea . "," . $id_twitterer . ",'" . $data->symbol . "','" . $data->operation . "'," . $data->value . ')'; DBConnection::getInstance()->query($sql); return DBConnection::getInstance()->getHandler()->insert_id; } /** * Checks whether the given twitterer exists * @param string $id * @return boolean */ public function exists($id) { $sql = "SELECT * FROM $this->table WHERE twitter_id='$id'"; $result = DBConnection::getInstance()->query($sql); return (boolean)$result->num_rows; } /** * Creates a new twitterer * @param stdClass $data * @return integer The new row id */ public function create(stdClass $data) { $sql = "INSERT INTO $this->table(twitter_id, access_token, access_token_secret) " . "VALUES ('" . $data->twitter_id . "','" . $data->access_token . "','" . $data->access_token_secret . "')"; DBConnection::getInstance()->query($sql); return DBConnection::getInstance()->getHandler()->insert_id; } /** * Updates the twitterer's data * @param stdClass $data * @return Mysqli object */ public function update(stdClass $data) { $sql = "UPDATE $this->table SET " . "access_token = '" . $data->access_token . "', " . "access_token_secret = '" . $data->access_token_secret . "' " . "WHERE twitter_id ='" . $data->twitter_id . "'"; return DBConnection::getInstance()->query($sql); } /** * Gets the last trading signal sent by the twitterer * @param type $id The twitterer id * @return mixed The last trading signal */ public function getLastSignal($id) { $sql = "SELECT * FROM signals WHERE id_twitterer=$id ORDER BY id DESC LIMIT 1"; $result = DBConnection::getInstance()->query($sql); if($result->num_rows == 1) { return $result->fetch_object(); } else { $signal = new stdClass; $signal->created_at = null; return $signal; } } }
模型/EA. PHP:
<?php require_once 'DBConnection.php'; /** * EA's simple OOP wrapper * * @author Jordi Bassagañas * @copyright 2014 Jordi Bassagañas * @link https://www.mql5.com/en/users/laplacianlab */ class EA { /** * @var string MySQL table */ protected $table = 'eas'; /** * Gets an EA by id * @param integer $id * @return stdClass */ public function get($id) { $sql = "SELECT * FROM $this->table WHERE id=$id"; return DBConnection::getInstance()->query($sql)->fetch_object(); } }
model/dbconnection.php：
<?php /** * DBConnection class * * @author Jordi Bassagañas * @copyright 2014 Jordi Bassagañas * @link https://www.mql5.com/en/users/laplacianlab */ class DBConnection { /** * @var DBConnection Singleton instance */ private static $instance; /** * @var mysqli Database handler */ private $mysqli; /** * Opens a new connection to the MySQL server */ private function __construct() { mysqli_report(MYSQLI_REPORT_STRICT); try { $this->mysqli = new MySQLI(DB_SERVER, DB_USER, DB_PASSWORD, DB_NAME); } catch (Exception $e) { throw new Exception('Unable to connect to the database, please, try again later.'); } } /** * Gets the singleton instance * @return type */ public static function getInstance() { if (!self::$instance instanceof self) self::$instance = new self; return self::$instance; } /** * Gets the database handler * @return mysqli */ public function getHandler() { return $this->mysqli; } /** * Runs the given query * @param string $sql * @return mixed */ public function query($sql) { $result = $this->mysqli->query($sql); if ($result === false) { throw new Exception('Unable to run query, please, try again later.'); } else { return $result; } } }
结论
我们已经开发了本文第一部分中描述的SDSS客户机，并根据决策完成了服务器端。我们最终使用了新的mql5本地化函数webrequest（）。关于规范方案的优缺点，我们已经看到webrequest（）最初不是用作Web服务，而是用于构建访问网页的get和post请求。然而，同时，我们决定使用这个新特性，因为它比从头开发自定义控件更安全。
一种更优雅的方法是在MQL5客户机和PHP服务器之间建立一个真正的REST会话，但是WebRequest（）更适合我们的特定需求。因此，Web服务接收URL编码的数据，并将其转换为PHP中的可管理格式。
我正在研究这个系统。现在，我可以发出自己的个人交易信号。这些功能可以为单个用户工作，但它们缺少一些可以在实际生产环境中完成复杂工作的部分。例如，瘦框架与数据库无关，所以您应该关心SQL注入。我们还没有解释如何确保MetaTrader 5终端和PHP应用程序之间的通信安全，因此请不要在实际环境中运行此应用程序，因为本文只介绍了它。
由MetaQuotes Software Corp.从英文翻译为
原文。https://www.mql5.com/en/articles/1044
附加文件下载zip database.txt（1.32 kb）dummy-u-ontimer.mq5（1.36 kb）dummy.mq5（3.27 kb）inde x.txt（6.08 kb）、tweeterer.txt（4.59 kb）、ea.txt（0.58 kb）、dbconnection.txt（1.54 kb）
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