Statemachine::checkTransitions() - Code Metrics - Inspection of "Fixing context distribution problem" - Metabor/Statemachine - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#20)

by Oliver

created 2016-11-17 21:43 UTC

Statemachine::checkTransitions() A

↳ Parent: Statemachine

Complexity

Conditions	2
Paths	2

Size

Total Lines	9
Code Lines	6

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	8
CRAP Score	2

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
c	3
b	0
f	0
dl	0
loc	9
ccs	8
cts	8
cp	1
rs	9.6666
cc	2
eloc	6
nc	2
nop	1
crap	2

<?php

namespace Metabor\Statemachine;

use Metabor\Callback\Callback;
use Metabor\Event\Dispatcher;
use Metabor\Observer\Subject;
use Metabor\Semaphore\NullMutex;
use Metabor\Statemachine\Exception\LockCanNotBeAcquiredException;
use Metabor\Statemachine\Exception\WrongEventForStateException;
use Metabor\Statemachine\Factory\TransitionSelector\OneOrNoneActiveTransition;
use Metabor\Statemachine\Transition\ActiveTransitionFilter;
use MetaborStd\Event\DispatcherInterface;
use MetaborStd\Event\EventInterface;
use MetaborStd\NamedInterface;
use MetaborStd\Semaphore\MutexInterface;
use MetaborStd\Statemachine\Factory\TransitionSelectorInterface;
use MetaborStd\Statemachine\ProcessInterface;
use MetaborStd\Statemachine\StateInterface;
use MetaborStd\Statemachine\StatemachineInterface;
use MetaborStd\Statemachine\TransitionInterface;

/**
 * @author Oliver Tischlinger
 */
class Statemachine extends Subject implements StatemachineInterface
{
    /**
     * @var object
     */
    private $subject;

    /**
     * @var StateInterface
     */
    private $currentState;

    /**
     * @var StateInterface
     */
    private $lastState;

    /**
     * @var DispatcherInterface
     */
    private $dispatcher;

    /**
     * @var EventInterface
     */
    private $currentEvent;

    /**
     * @var \ArrayAccess
     */
    private $currentContext;

    /**
     * @var TransitionSelectorInterface
     */
    private $transitonSelector;

    /**
     * @var TransitionInterface
     */
    private $selectedTransition;

    /**
     * @var ProcessInterface
     */
    private $process;

    /**
     * @var MutexInterface
     */
    private $mutex;

    /**
     * @param object                      $subject
     * @param ProcessInterface            $process
     * @param string                      $stateName
     * @param TransitionSelectorInterface $transitonSelector
     * @param MutexInterface              $mutex
     */
    public function __construct(
        $subject,
        ProcessInterface $process,
        $stateName = null,
        TransitionSelectorInterface $transitonSelector = null,
        MutexInterface $mutex = null
    ) {
        parent::__construct();
        $this->subject = $subject;
        if ($stateName) {
''   == false // true
''   == null  // true
'ab' == false // false
'ab' == null  // false

// It is often better to use strict comparison
'' === false // false
'' === null  // false
            $this->currentState = $process->getState($stateName);
        } else {
            $this->currentState = $process->getInitialState();
        }
        if ($transitonSelector) {
            $this->transitonSelector = $transitonSelector;
        } else {
            $this->transitonSelector = new OneOrNoneActiveTransition();
        }
        $this->process = $process;
        if ($mutex) {
            $this->mutex = $mutex;
        } else {
            $this->mutex = new NullMutex();
        }
    }

    /**
     * @return ProcessInterface
     */
    public function getProcess()
    {
        return $this->process;
    }

    /**
     * @see MetaborStd\Statemachine.StatemachineInterface::getCurrentState()
     */
    public function getCurrentState()
    {
        return $this->currentState;
    }

    /**
     * @return StateInterface
     */
    public function getLastState()
    {
        return $this->lastState;
    }

    /**
     * @param \ArrayAccess   $context
     * @param EventInterface $event
     */
    protected function doCheckTransitions(\ArrayAccess $context, EventInterface $event = null)
    {
        try {
            $transitions = $this->currentState->getTransitions();
            $activeTransitions = new ActiveTransitionFilter($transitions, $this->getSubject(), $context, $event);
            $this->selectedTransition = $this->transitonSelector->selectTransition($activeTransitions);
            if ($this->selectedTransition) {
                $targetState = $this->selectedTransition->getTargetState();
                if ($this->currentState != $targetState) {
                    $this->lastState = $this->currentState;
                    $this->currentState = $targetState;
                    $this->currentContext = $context;
                    $this->currentEvent = $event;
                    $this->notify();
                    $this->currentContext = null;
                    $this->currentEvent = null;
                    $this->selectedTransition = null;
                    $this->lastState = null;
                }
                $this->checkTransitions($context);
            }
        } catch (\Exception $exception) {
            $message = 'Exception was thrown when doing a transition from current state "' . $this->currentState->getName() . '"';
            if ($this->currentEvent instanceof NamedInterface) {
                $message .= ' with event "' . $this->currentEvent->getName() . '"';
            }
            throw new \RuntimeException($message, 0, $exception);
        }
    }

    /**
     * @return \MetaborStd\Statemachine\TransitionInterface
     */
    public function getSelectedTransition()
    {
        return $this->selectedTransition;
    }

    /**
     * is called after dispatcher was executed.
     */
    public function onDispatcherReady()
    {
        if ($this->dispatcher && $this->dispatcher->isReady()) {
            $context = $this->currentContext;
            $event = $this->currentEvent;
            $this->dispatcher = null;
            $this->currentContext = null;
            $this->currentEvent = null;
            $this->doCheckTransitions($context, $event);
            $this->mutex->releaseLock();
        }
    }

    /**
     * @param DispatcherInterface $dispatcher
     * @param string              $name
     * @param \ArrayAccess        $context
     *
     * @throws \RuntimeException
     */
    public function dispatchEvent(DispatcherInterface $dispatcher, $name, \ArrayAccess $context = null)
    {
        if ($this->dispatcher) {
            throw new \RuntimeException('Event dispatching is still running!');
        } else {
            if ($this->currentState->hasEvent($name)) {
                $this->acquireLockOrThrowException();
                $this->dispatcher = $dispatcher;

                if ($context) {
                    $this->currentContext = $context;
                } else {
                    $this->currentContext = new \ArrayIterator(array());
                }
                $this->currentEvent = $this->currentState->getEvent($name);

                $dispatcher->dispatch($this->currentEvent, array($this->subject, $this->currentContext), new Callback(array($this, 'onDispatcherReady')));
            } else {
                throw new WrongEventForStateException($this->currentState->getName(), $name);
            }
        }
    }

    /**
     * @param string $name
     * @param \ArrayAccess|null $context
     */
    public function triggerEvent($name, \ArrayAccess $context = null)
    {
        $dispatcher = new Dispatcher();
        $this->dispatchEvent($dispatcher, $name, $context);
        $dispatcher();
    }

    /**
     * @param \ArrayAccess|null $context
     */
    public function checkTransitions(\ArrayAccess $context = null)
    {
        $this->acquireLockOrThrowException();
        if (!$context) {
            $context = new \ArrayIterator(array());
        }
        $this->doCheckTransitions($context);
        $this->mutex->releaseLock();
    }

    /**
     * @see \MetaborStd\Statemachine\StatemachineInterface::getSubject()
     */
    public function getSubject()
    {
        return $this->subject;
    }

    /**
     * @return \ArrayAccess
     */
    public function getCurrentContext()
    {
        return $this->currentContext;
    }

    /**
     * @throws LockCanNotBeAcquiredException
     */
    protected function acquireLockOrThrowException()
    {
        if (!$this->acquireLock()) {
            throw new LockCanNotBeAcquiredException('Lock can not be acquired!');
        }
    }

    /**
     * Use this function if you want to aquire lock before calling triggerEvent or checkTransitions.
     * Lock is aquired automatically when calling dispatchEvent or checkTransitions.
     *
     * @return bool
     */
    public function acquireLock()
    {
        if ($this->mutex->isAcquired()) {
            return true;
        } else {
            return $this->mutex->acquireLock();
        }
    }
}


1		<?php
2
3		namespace Metabor\Statemachine;
4
5		use Metabor\Callback\Callback;
6		use Metabor\Event\Dispatcher;
7		use Metabor\Observer\Subject;
8		use Metabor\Semaphore\NullMutex;
9		use Metabor\Statemachine\Exception\LockCanNotBeAcquiredException;
10		use Metabor\Statemachine\Exception\WrongEventForStateException;
11		use Metabor\Statemachine\Factory\TransitionSelector\OneOrNoneActiveTransition;
12		use Metabor\Statemachine\Transition\ActiveTransitionFilter;
13		use MetaborStd\Event\DispatcherInterface;
14		use MetaborStd\Event\EventInterface;
15		use MetaborStd\NamedInterface;
16		use MetaborStd\Semaphore\MutexInterface;
17		use MetaborStd\Statemachine\Factory\TransitionSelectorInterface;
18		use MetaborStd\Statemachine\ProcessInterface;
19		use MetaborStd\Statemachine\StateInterface;
20		use MetaborStd\Statemachine\StatemachineInterface;
21		use MetaborStd\Statemachine\TransitionInterface;
22
23		/**
24		* @author Oliver Tischlinger
25		*/
26		class Statemachine extends Subject implements StatemachineInterface
27		{
28		/**
29		* @var object
30		*/
31		private $subject;
32
33		/**
34		* @var StateInterface
35		*/
36		private $currentState;
37
38		/**
39		* @var StateInterface
40		*/
41		private $lastState;
42
43		/**
44		* @var DispatcherInterface
45		*/
46		private $dispatcher;
47
48		/**
49		* @var EventInterface
50		*/
51		private $currentEvent;
52
53		/**
54		* @var \ArrayAccess
55		*/
56		private $currentContext;
57
58		/**
59		* @var TransitionSelectorInterface
60		*/
61		private $transitonSelector;
62
63		/**
64		* @var TransitionInterface
65		*/
66		private $selectedTransition;
67
68		/**
69		* @var ProcessInterface
70		*/
71		private $process;
72
73		/**
74		* @var MutexInterface
75		*/
76		private $mutex;
77
78		/**
79		* @param object $subject
80		* @param ProcessInterface $process
81		* @param string $stateName
82		* @param TransitionSelectorInterface $transitonSelector
83		* @param MutexInterface $mutex
84		*/
85	9	public function __construct(
86		$subject,
87		ProcessInterface $process,
88		$stateName = null,
89		TransitionSelectorInterface $transitonSelector = null,
90		MutexInterface $mutex = null
91		) {
92	9	parent::__construct();
93	9	$this->subject = $subject;
94	9	if ($stateName) {
		0 ignored issues – show Bug Best Practice introduced 2015-11-20 21:27 UTC by Report Bug Copy Issue Report The expression `$stateName` of type `string\|null` is loosely compared to `true`; this is ambiguous if the string can be empty. You might want to explicitly use `!== null` instead. In PHP, under loose comparison (like `==`, or `!=`, or `switch` conditions), values of different types might be equal. For `string` values, the empty string `''` is a special case, in particular the following results might be unexpected: '' == false // true '' == null // true 'ab' == false // false 'ab' == null // false // It is often better to use strict comparison '' === false // false '' === null // false Loading history...
95		$this->currentState = $process->getState($stateName);
96		} else {
97	9	$this->currentState = $process->getInitialState();
98		}
99	9	if ($transitonSelector) {
100		$this->transitonSelector = $transitonSelector;
101		} else {
102	9	$this->transitonSelector = new OneOrNoneActiveTransition();
103		}
104	9	$this->process = $process;
105	9	if ($mutex) {
106		$this->mutex = $mutex;
107		} else {
108	9	$this->mutex = new NullMutex();
109		}
110	9	}
111
112		/**
113		* @return ProcessInterface
114		*/
115		public function getProcess()
116		{
117		return $this->process;
118		}
119
120		/**
121		* @see MetaborStd\Statemachine.StatemachineInterface::getCurrentState()
122		*/
123	6	public function getCurrentState()
124		{
125	6	return $this->currentState;
126		}
127
128		/**
129		* @return StateInterface
130		*/
131	1	public function getLastState()
132		{
133	1	return $this->lastState;
134		}
135
136		/**
137		* @param \ArrayAccess $context
138		* @param EventInterface $event
139		*/
140	3	protected function doCheckTransitions(\ArrayAccess $context, EventInterface $event = null)
141		{
142		try {
143	3	$transitions = $this->currentState->getTransitions();
144	3	$activeTransitions = new ActiveTransitionFilter($transitions, $this->getSubject(), $context, $event);
145	3	$this->selectedTransition = $this->transitonSelector->selectTransition($activeTransitions);
146	3	if ($this->selectedTransition) {
147	3	$targetState = $this->selectedTransition->getTargetState();
148	3	if ($this->currentState != $targetState) {
149	3	$this->lastState = $this->currentState;
150	3	$this->currentState = $targetState;
151	3	$this->currentContext = $context;
152	3	$this->currentEvent = $event;
153	3	$this->notify();
154	3	$this->currentContext = null;
155	3	$this->currentEvent = null;
156	3	$this->selectedTransition = null;
157	3	$this->lastState = null;
158	3	}
159	3	$this->checkTransitions($context);
160	3	}
161	3	} catch (\Exception $exception) {
162		$message = 'Exception was thrown when doing a transition from current state "' . $this->currentState->getName() . '"';
163		if ($this->currentEvent instanceof NamedInterface) {
164		$message .= ' with event "' . $this->currentEvent->getName() . '"';
165		}
166		throw new \RuntimeException($message, 0, $exception);
167		}
168	3	}
169
170		/**
171		* @return \MetaborStd\Statemachine\TransitionInterface
172		*/
173	1	public function getSelectedTransition()
174		{
175	1	return $this->selectedTransition;
176		}
177
178		/**
179		* is called after dispatcher was executed.
180		*/
181	3	public function onDispatcherReady()
182		{
183	3	if ($this->dispatcher && $this->dispatcher->isReady()) {
184	3	$context = $this->currentContext;
185	3	$event = $this->currentEvent;
186	3	$this->dispatcher = null;
187	3	$this->currentContext = null;
188	3	$this->currentEvent = null;
189	3	$this->doCheckTransitions($context, $event);
190	3	$this->mutex->releaseLock();
191	3	}
192	3	}
193
194		/**
195		* @param DispatcherInterface $dispatcher
196		* @param string $name
197		* @param \ArrayAccess $context
198		*
199		* @throws \RuntimeException
200		*/
201	4	public function dispatchEvent(DispatcherInterface $dispatcher, $name, \ArrayAccess $context = null)
202		{
203	4	if ($this->dispatcher) {
204		throw new \RuntimeException('Event dispatching is still running!');
205		} else {
206	4	if ($this->currentState->hasEvent($name)) {
207	3	$this->acquireLockOrThrowException();
208	3	$this->dispatcher = $dispatcher;
209
210	3	if ($context) {
211	1	$this->currentContext = $context;
212	1	} else {
213	3	$this->currentContext = new \ArrayIterator(array());
214		}
215	3	$this->currentEvent = $this->currentState->getEvent($name);
216
217	3	$dispatcher->dispatch($this->currentEvent, array($this->subject, $this->currentContext), new Callback(array($this, 'onDispatcherReady')));
218	3	} else {
219	1	throw new WrongEventForStateException($this->currentState->getName(), $name);
220		}
221		}
222	3	}
223
224		/**
225		* @param string $name
226		* @param \ArrayAccess\|null $context
227		*/
228	4	public function triggerEvent($name, \ArrayAccess $context = null)
229		{
230	4	$dispatcher = new Dispatcher();
231	4	$this->dispatchEvent($dispatcher, $name, $context);
232	3	$dispatcher();
233	3	}
234
235		/**
236		* @param \ArrayAccess\|null $context
237		*/
238	3	public function checkTransitions(\ArrayAccess $context = null)
239		{
240	3	$this->acquireLockOrThrowException();
241	3	if (!$context) {
242	1	$context = new \ArrayIterator(array());
243	1	}
244	3	$this->doCheckTransitions($context);
245	3	$this->mutex->releaseLock();
246	3	}
247
248		/**
249		* @see \MetaborStd\Statemachine\StatemachineInterface::getSubject()
250		*/
251	6	public function getSubject()
252		{
253	6	return $this->subject;
254		}
255
256		/**
257		* @return \ArrayAccess
258		*/
259	1	public function getCurrentContext()
260		{
261	1	return $this->currentContext;
262		}
263
264		/**
265		* @throws LockCanNotBeAcquiredException
266		*/
267	3	protected function acquireLockOrThrowException()
268		{
269	3	if (!$this->acquireLock()) {
270		throw new LockCanNotBeAcquiredException('Lock can not be acquired!');
271		}
272	3	}
273
274		/**
275		* Use this function if you want to aquire lock before calling triggerEvent or checkTransitions.
276		* Lock is aquired automatically when calling dispatchEvent or checkTransitions.
277		*
278		* @return bool
279		*/
280	3	public function acquireLock()
281		{
282	3	if ($this->mutex->isAcquired()) {
283	3	return true;
284		} else {
285	3	return $this->mutex->acquireLock();
286		}
287		}
288		}
289

Metabor / Statemachine

Pull Request — master (#20)

Statemachine::checkTransitions() A

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