1<?php
2
3/**
4 * Hoa
5 *
6 *
7 * @license
8 *
9 * New BSD License
10 *
11 * Copyright © 2007-2017, Hoa community. All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions are met:
15 *     * Redistributions of source code must retain the above copyright
16 *       notice, this list of conditions and the following disclaimer.
17 *     * Redistributions in binary form must reproduce the above copyright
18 *       notice, this list of conditions and the following disclaimer in the
19 *       documentation and/or other materials provided with the distribution.
20 *     * Neither the name of the Hoa nor the names of its contributors may be
21 *       used to endorse or promote products derived from this software without
22 *       specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37namespace Hoa\Event;
38
39/**
40 * Trait \Hoa\Event\Listens.
41 *
42 * Implementation of a listener.
43 *
44 * @copyright  Copyright © 2007-2017 Hoa community
45 * @license    New BSD License
46 */
47trait Listens
48{
49    /**
50     * Listener instance.
51     *
52     * @var \Hoa\Event\Listener
53     */
54    protected $_listener = null;
55
56
57
58    /**
59     * Attach a callable to a listenable component.
60     *
61     * @param   string  $listenerId    Listener ID.
62     * @param   mixed   $callable      Callable.
63     * @return  \Hoa\Event\Listenable
64     */
65    public function on($listenerId, $callable)
66    {
67        $listener = $this->getListener();
68
69        if (null === $listener) {
70            throw new Exception(
71                'Cannot attach a callable to the listener %s because ' .
72                'it has not been initialized yet.',
73                0,
74                get_class($this)
75            );
76        }
77
78        $listener->attach($listenerId, $callable);
79
80        return $this;
81    }
82
83    /**
84     * Set listener.
85     *
86     * @param  \Hoa\Event\Listener  $listener    Listener.
87     * @return \Hoa\Event\Listener
88     */
89    protected function setListener(Listener $listener)
90    {
91        $old             = $this->_listener;
92        $this->_listener = $listener;
93
94        return $old;
95    }
96
97    /**
98     * Get listener.
99     *
100     * @return \Hoa\Event\Listener
101     */
102    protected function getListener()
103    {
104        return $this->_listener;
105    }
106}
107