Upd.

modules/wizard-httpclient/src-php/framework/httpclient/HttpAsyncResponse.php

@@ -0,0 +1,55 @@
+<?php
+namespace framework\httpclient;
+
+/**
+ * Class HttpAsyncResponse
+ * @package bundle\http
+ * @packages httpclient
+ */
+class HttpAsyncResponse
+{
+    protected $onSuccess;
+    protected $onError;
+    protected $onDone;
+
+    /**
+     * @param callable $callback
+     * @return HttpAsyncResponse
+     */
+    function whenDone(callable $callback)
+    {
+        $this->onDone = $callback;
+        return $this;
+    }
+
+    /**
+     * @param callable $callback
+     * @return HttpAsyncResponse
+     */
+    function whenSuccess(callable $callback)
+    {
+        $this->onSuccess = $callback;
+        return $this;
+    }
+
+    /**
+     * @param callable $callback
+     * @return HttpAsyncResponse
+     */
+    function whenError(callable $callback)
+    {
+        $this->onError = $callback;
+        return $this;
+    }
+
+    /**
+     * @param HttpResponse $response
+     */
+    public function trigger(HttpResponse $response)
+    {
+        if ($this->onSuccess && $response->isSuccess()) call_user_func($this->onSuccess, $response);
+        if ($this->onError && $response->isFail()) call_user_func($this->onError, $response);
+
+        if ($this->onDone) call_user_func($this->onDone, $response);
+    }
+}

modules/wizard-httpclient/src-php/framework/httpclient/HttpChecker.php

@@ -0,0 +1,175 @@
+<?php
+namespace framework\httpclient;
+
+use framework\core\Component;
+use framework\core\Event;
+use framework\core\Logger;
+use php\lang\Invoker;
+use php\time\Timer;
+use timer\AccurateTimer;
+
+/**
+ * Class HttpChecker
+ * @package bundle\http
+ * @packages httpclient
+ *
+ * @property int $checkInterval
+ */
+class HttpChecker extends Component
+{
+    /**
+     * @var string
+     */
+    public $url;
+
+    /**
+     * @var bool
+     */
+    public $autoStart = true;
+
+    /**
+     * @var int
+     */
+    protected $_checkInterval = 10000;
+
+    /**
+     * @var HttpClient
+     */
+    protected $client;
+
+    /**
+     * @var Timer
+     */
+    protected $checkTimer;
+
+    /**
+     * @var boolean
+     */
+    protected $available = null;
+
+    /**
+     * ...
+     */
+    function __construct()
+    {
+        parent::__construct();
+
+        $this->client = new HttpClient();
+        $this->client->userAgent = 'Http Checker 1.0';
+        $this->client->readTimeout = 15000;
+    }
+
+    /**
+     * @event addTo
+     * @param Event $e
+     */
+    private function handleAddTo(Event $e)
+    {
+        if ($this->autoStart) {
+            $this->start();
+        }
+    }
+
+    protected function doInterval()
+    {
+        $active = (bool) $this->checkTimer;
+        $this->stop();
+
+        Logger::debug("http checker ping '{0}' ...", $this->url);
+
+        $this->client->getAsync($this->url, [], function (HttpResponse $response) use ($active) {
+            if ($response->statusCode() == 200) {
+                if ($this->available !== true) {
+                    $this->trigger(new Event('online', $this));
+                }
+
+                $this->available = true;
+            } else {
+                if ($this->available !== false) {
+                    $this->trigger(new Event('offline', $this));
+                }
+
+                $this->available = false;
+            }
+
+            if ($active) {
+                $this->start();
+            }
+        });
+    }
+
+    /**
+     * Check status of url.
+     */
+    public function ping()
+    {
+        $this->doInterval();
+    }
+
+    /**
+     * Start checker worker.
+     */
+    public function start()
+    {
+        $this->checkTimer = Timer::every($this->_checkInterval, Invoker::of([$this, 'doInterval']));
+        $this->ping();
+    }
+
+    /**
+     * Stop checker worker.
+     */
+    public function stop()
+    {
+        if ($this->checkTimer) {
+            $this->checkTimer->cancel();
+            $this->checkTimer = null;
+        }
+    }
+
+    /**
+     * @return HttpClient
+     */
+    public function client()
+    {
+        return $this->client;
+    }
+
+    /**
+     * @return int
+     */
+    protected function getCheckInterval()
+    {
+        return $this->_checkInterval;
+    }
+
+    /**
+     * @param int $checkInterval
+     */
+    protected function setCheckInterval($checkInterval)
+    {
+        $this->_checkInterval = $checkInterval;
+        $this->stop();
+        $this->start();
+    }
+
+    /**
+     * @return bool
+     */
+    public function isOffline()
+    {
+        return $this->available === false;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isOnline()
+    {
+        return $this->available === true;
+    }
+
+    public function isUnknown()
+    {
+        return $this->available === null;
+    }
+}