Server.php

<?php

/**
 * Hoa
 *
 *
 * @license
 *
 * New BSD License
 *
 * Copyright © 2007-2017, Hoa community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Hoa nor the names of its contributors may be
 *       used to endorse or promote products derived from this software without
 *       specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

namespace Hoa\Eventsource;

use Hoa\Http;

/**
 * Class \Hoa\Eventsource\Server.
 *
 * A cross-protocol EventSource server.
 *
 * @copyright  Copyright © 2007-2017 Hoa community
 * @license    New BSD License
 */
class Server
{
    /**
     * Mime type.
     *
     * @const string
     */
    const MIME_TYPE = 'text/event-stream';

    /**
     * Current event.
     *
     * @var string
     */
    protected $_event    = null;

    /**
     * HTTP response.
     *
     * @var \Hoa\Http\Response
     */
    protected $_response = null;



    /**
     * Start an event source.
     *
     * @param   bool  $verifyHeaders    Verify headers or not.
     * @throws  \Hoa\Eventsource\Exception
     */
    public function __construct($verifyHeaders = true)
    {
        if (true === $verifyHeaders && true === headers_sent($file, $line)) {
            throw new Exception(
                'Headers already sent in %s at line %d, cannot send data ' .
                'to client correctly.',
                0,
                [$file, $line]
            );
        }

        $mimes  = preg_split('#\s*,\s*#', Http\Runtime::getHeader('accept'));
        $gotcha = false;

        foreach ($mimes as $mime) {
            if (0 !== preg_match('#^(\*/\*|' . self::MIME_TYPE . ';?)#', $mime)) {
                $gotcha = true;

                break;
            }
        }

        $this->_response = new Http\Response(false);

        if (false === $gotcha) {
            $this->_response->sendHeader(
                'Status',
                Http\Response::STATUS_NOT_ACCEPTABLE
            );
            $this->_response->sendHeader(
                'Content-Type',
                'text/plain; charset=utf-8'
            );

            throw new Exception(
                'Client does not accept %s.',
                1,
                self::MIME_TYPE
            );
        }

        $this->_response->sendHeader('Content-Type',      self::MIME_TYPE);
        $this->_response->sendHeader('Transfer-Encoding', 'identity');
        $this->_response->sendHeader('Cache-Control',     'no-cache');
        $this->_response->sendHeader('X-Accel-Buffering', 'no');
        $this->_response->newBuffer();

        return;
    }

    /**
     * Send an event.
     *
     * @param   string  $data     Data.
     * @param   string  $id       ID (empty string to reset).
     * @return  void
     */
    public function send($data, $id = null)
    {
        if (null !== $this->_event) {
            $this->_response->writeAll('event: ' . $this->_event . "\n");
            $this->_event = null;
        }

        $this->_response->writeAll(
            'data: ' .
            preg_replace("#(" . CRLF . "|\n|\r)#", "\n" . 'data: ', $data)
        );

        if (null !== $id) {
            $this->_response->writeAll("\n" . 'id');

            if (!empty($id)) {
                $this->_response->writeAll(': ' . $id);
            }
        }

        $this->_response->writeAll("\n\n");
        $this->_response->flush(true);

        return;
    }

    /**
     * Set the reconnection time for the client.
     *
     * @param   int    $ms    Time in milliseconds.
     * @return  void
     */
    public function setReconnectionTime($ms)
    {
        $this->_response->writeAll('retry: ' . $ms . "\n\n");
        $this->_response->flush(true);

        return;
    }

    /**
     * Select an event where to send data.
     *
     * @param   string  $event    Event.
     * @return  \Hoa\Eventsource\Server
     * @throws  \Hoa\Eventsource\Exception
     */
    public function __get($event)
    {
        if (false === (bool) preg_match('##u', $event)) {
            throw new Exception(
                'Event name %s must be in UTF-8.',
                2,
                $event
            );
        }

        if (0 !== preg_match('#[:' . CRLF . ']#u', $event)) {
            throw new Exception(
                'Event name %s contains illegal characters.',
                3,
                $event
            );
        }

        $this->_event = $event;

        return $this;
    }

    /**
     * Get last ID.
     *
     * @return  string
     */
    public function getLastId()
    {
        return Http\Runtime::getHeader('Last-Event-ID') ?: '';
    }
}