Complex classes like StateMachine often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use StateMachine, and based on these observations, apply Extract Interface, too.
1 | <?php |
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23 | class StateMachine implements StateMachineInterface |
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24 | { |
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25 | /** |
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26 | * The stateful object. |
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27 | * |
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28 | * @var object |
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29 | */ |
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30 | protected $object; |
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31 | |||
32 | /** |
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33 | * The available states. |
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34 | * |
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35 | * @var array |
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36 | */ |
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37 | protected $states = array(); |
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38 | |||
39 | /** |
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40 | * The available transitions. |
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41 | * |
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42 | * @var array |
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43 | */ |
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44 | protected $transitions = array(); |
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45 | |||
46 | /** |
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47 | * The current state. |
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48 | * |
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49 | * @var StateInterface |
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50 | */ |
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51 | protected $currentState; |
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52 | |||
53 | /** |
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54 | * @var EventDispatcherInterface |
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55 | */ |
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56 | protected $dispatcher; |
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57 | |||
58 | /** |
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59 | * @var StateAccessorInterface |
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60 | */ |
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61 | protected $stateAccessor; |
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62 | |||
63 | /** |
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64 | * @var string |
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65 | */ |
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66 | protected $graph; |
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67 | |||
68 | /** |
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69 | * @param object $object |
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70 | * @param EventDispatcherInterface $dispatcher |
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71 | * @param StateAccessorInterface $stateAccessor |
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72 | */ |
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73 | 220 | public function __construct( |
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74 | $object = null, |
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75 | EventDispatcherInterface $dispatcher = null, |
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76 | StateAccessorInterface $stateAccessor = null |
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77 | ) { |
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78 | 220 | $this->object = $object; |
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79 | 220 | $this->dispatcher = $dispatcher ?: new EventDispatcher(); |
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80 | 220 | $this->stateAccessor = $stateAccessor ?: new PropertyPathStateAccessor(); |
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81 | 220 | } |
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82 | |||
83 | /** |
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84 | * {@inheritdoc} |
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85 | */ |
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86 | 160 | public function initialize() |
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87 | { |
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88 | 160 | if (null === $this->object) { |
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89 | throw new Exception\ObjectException('No object bound to the State Machine'); |
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90 | } |
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91 | |||
92 | try { |
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93 | 160 | $initialState = $this->stateAccessor->getState($this->object); |
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94 | 64 | } catch (Exception\NoSuchPropertyException $e) { |
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95 | throw new Exception\ObjectException(sprintf( |
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96 | 'StateMachine can\'t be initialized because the defined property_path of object "%s" does not exist.', |
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97 | $this->getObject() ? get_class($this->getObject()) : null, |
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98 | ), $e->getCode(), $e); |
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99 | } |
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100 | |||
101 | 160 | if (null === $initialState) { |
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102 | 20 | $initialState = $this->findInitialState(); |
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103 | 20 | $this->stateAccessor->setState($this->object, $initialState); |
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104 | |||
105 | 20 | $this->dispatcher->dispatch(FiniteEvents::SET_INITIAL_STATE, new StateMachineEvent($this)); |
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106 | 8 | } |
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107 | |||
108 | 160 | $this->currentState = $this->getState($initialState); |
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109 | |||
110 | 160 | $this->dispatcher->dispatch(FiniteEvents::INITIALIZE, new StateMachineEvent($this)); |
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111 | 160 | } |
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112 | |||
113 | /** |
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114 | * {@inheritdoc} |
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115 | * |
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116 | * @throws Exception\StateException |
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117 | */ |
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118 | 20 | public function apply($transitionName, array $parameters = array()) |
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119 | { |
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120 | 20 | $transition = $this->getTransition($transitionName); |
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121 | 20 | $event = new TransitionEvent($this->getCurrentState(), $transition, $this, $parameters); |
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122 | 20 | if (!$this->can($transition, $parameters)) { |
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123 | 5 | throw new Exception\StateException(sprintf( |
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124 | 5 | 'The "%s" transition can not be applied to the "%s" state of object "%s" with graph "%s".', |
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125 | 5 | $transition->getName(), |
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126 | 5 | $this->currentState->getName(), |
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127 | 5 | $this->getObject() ? get_class($this->getObject()) : null, |
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128 | 5 | $this->getGraph() |
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129 | 2 | )); |
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130 | } |
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131 | |||
132 | 20 | $this->dispatchTransitionEvent($transition, $event, FiniteEvents::PRE_TRANSITION); |
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133 | |||
134 | 20 | $returnValue = $transition->process($this); |
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135 | 20 | $this->stateAccessor->setState($this->object, $transition->getState()); |
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136 | 20 | $this->currentState = $this->getState($transition->getState()); |
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137 | |||
138 | 20 | $this->dispatchTransitionEvent($transition, $event, FiniteEvents::POST_TRANSITION); |
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139 | |||
140 | 20 | return $returnValue; |
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141 | } |
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142 | |||
143 | /** |
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144 | * {@inheritdoc} |
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145 | */ |
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146 | 55 | public function can($transition, array $parameters = array()) |
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147 | { |
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148 | 55 | $transition = $transition instanceof TransitionInterface ? $transition : $this->getTransition($transition); |
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149 | |||
150 | 55 | if (null !== $transition->getGuard() && !call_user_func($transition->getGuard(), $this)) { |
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151 | 5 | return false; |
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152 | } |
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153 | |||
154 | 50 | if (!in_array($transition->getName(), $this->getCurrentState()->getTransitions())) { |
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155 | 30 | return false; |
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156 | } |
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157 | |||
158 | 50 | $event = new TransitionEvent($this->getCurrentState(), $transition, $this, $parameters); |
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159 | 50 | $this->dispatchTransitionEvent($transition, $event, FiniteEvents::TEST_TRANSITION); |
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160 | |||
161 | 50 | return !$event->isRejected(); |
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162 | } |
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163 | |||
164 | /** |
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165 | * {@inheritdoc} |
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166 | */ |
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167 | 185 | public function addState($state) |
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168 | { |
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169 | 185 | if (!$state instanceof StateInterface) { |
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170 | 175 | $state = new State($state); |
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171 | 70 | } |
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172 | |||
173 | 185 | $this->states[$state->getName()] = $state; |
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174 | 185 | } |
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175 | |||
176 | /** |
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177 | * {@inheritdoc} |
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178 | */ |
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179 | 180 | public function addTransition($transition, $initialState = null, $finalState = null) |
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180 | { |
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181 | 180 | if ((null === $initialState || null === $finalState) && !$transition instanceof TransitionInterface) { |
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182 | throw new \InvalidArgumentException( |
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183 | 'You must provide a TransitionInterface instance or the $transition, '. |
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184 | '$initialState and $finalState parameters' |
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185 | ); |
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186 | } |
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187 | // If transition isn't a TransitionInterface instance, we create one from the states date |
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188 | 180 | if (!$transition instanceof TransitionInterface) { |
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189 | try { |
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190 | 155 | $transition = $this->getTransition($transition); |
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191 | 155 | } catch (Exception\TransitionException $e) { |
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192 | 155 | $transition = new Transition($transition, $initialState, $finalState); |
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193 | } |
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194 | 62 | } |
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195 | |||
196 | 180 | $this->transitions[$transition->getName()] = $transition; |
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197 | |||
198 | // We add missings states to the State Machine |
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199 | try { |
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200 | 180 | $this->getState($transition->getState()); |
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201 | 126 | } catch (Exception\StateException $e) { |
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202 | 90 | $this->addState($transition->getState()); |
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203 | } |
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204 | 180 | foreach ($transition->getInitialStates() as $state) { |
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205 | try { |
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206 | 180 | $this->getState($state); |
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207 | 93 | } catch (Exception\StateException $e) { |
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208 | 35 | $this->addState($state); |
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209 | } |
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210 | 180 | $state = $this->getState($state); |
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211 | 180 | if ($state instanceof State) { |
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212 | 180 | $state->addTransition($transition); |
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213 | 72 | } |
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214 | 72 | } |
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215 | 180 | } |
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216 | |||
217 | /** |
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218 | * {@inheritdoc} |
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219 | */ |
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220 | 160 | public function getTransition($name) |
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221 | { |
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222 | 160 | if (!isset($this->transitions[$name])) { |
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223 | 155 | throw new Exception\TransitionException(sprintf( |
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224 | 155 | 'Unable to find a transition called "%s" on object "%s" with graph "%s".', |
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225 | 155 | $name, |
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226 | 155 | $this->getObject() ? get_class($this->getObject()) : null, |
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227 | 155 | $this->getGraph() |
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228 | 62 | )); |
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229 | } |
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230 | |||
231 | 55 | return $this->transitions[$name]; |
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232 | } |
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233 | |||
234 | /** |
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235 | * {@inheritdoc} |
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236 | */ |
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237 | 185 | public function getState($name) |
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238 | { |
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239 | 185 | $name = (string) $name; |
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240 | |||
241 | 185 | if (!isset($this->states[$name])) { |
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242 | 95 | throw new Exception\StateException(sprintf( |
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243 | 95 | 'Unable to find a state called "%s" on object "%s" with graph "%s".', |
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244 | 95 | $name, |
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245 | 95 | $this->getObject() ? get_class($this->getObject()) : null, |
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246 | 95 | $this->getGraph() |
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247 | 38 | )); |
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248 | } |
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249 | |||
250 | 185 | return $this->states[$name]; |
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251 | } |
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252 | |||
253 | /** |
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254 | * {@inheritdoc} |
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255 | */ |
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256 | 5 | public function getTransitions() |
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257 | { |
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258 | 5 | return array_keys($this->transitions); |
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259 | } |
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260 | |||
261 | /** |
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262 | * {@inheritdoc} |
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263 | */ |
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264 | 5 | public function getStates() |
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265 | { |
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266 | 5 | return array_keys($this->states); |
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267 | } |
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268 | |||
269 | /** |
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270 | * {@inheritdoc} |
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271 | */ |
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272 | 150 | public function setObject($object) |
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273 | { |
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274 | 150 | $this->object = $object; |
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275 | 150 | } |
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276 | |||
277 | /** |
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278 | * {@inheritdoc} |
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279 | */ |
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280 | 175 | public function getObject() |
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281 | { |
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282 | 175 | return $this->object; |
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283 | } |
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284 | |||
285 | /** |
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286 | * {@inheritdoc} |
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287 | */ |
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288 | 115 | public function getCurrentState() |
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289 | { |
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290 | 115 | return $this->currentState; |
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291 | } |
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292 | |||
293 | /** |
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294 | * Find and return the Initial state if exists. |
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295 | * |
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296 | * @return string |
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297 | * |
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298 | * @throws Exception\StateException |
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299 | */ |
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300 | 20 | protected function findInitialState() |
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301 | { |
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302 | 20 | foreach ($this->states as $state) { |
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303 | 20 | if (State::TYPE_INITIAL === $state->getType()) { |
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304 | 20 | return $state->getName(); |
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305 | } |
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306 | } |
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307 | |||
308 | throw new Exception\StateException(sprintf( |
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309 | 'No initial state found on object "%s" with graph "%s".', |
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310 | $this->getObject() ? get_class($this->getObject()) : null, |
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311 | $this->getGraph() |
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312 | )); |
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313 | } |
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314 | |||
315 | /** |
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316 | * @param EventDispatcherInterface $dispatcher |
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317 | */ |
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318 | public function setDispatcher(EventDispatcherInterface $dispatcher) |
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319 | { |
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320 | $this->dispatcher = $dispatcher; |
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321 | } |
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322 | |||
323 | /** |
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324 | * @return EventDispatcherInterface |
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325 | */ |
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326 | 5 | public function getDispatcher() |
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327 | { |
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328 | 5 | return $this->dispatcher; |
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329 | } |
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330 | |||
331 | /** |
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332 | * @param StateAccessorInterface $stateAccessor |
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333 | */ |
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334 | 5 | public function setStateAccessor(StateAccessorInterface $stateAccessor) |
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335 | { |
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336 | 5 | $this->stateAccessor = $stateAccessor; |
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337 | 5 | } |
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338 | |||
339 | /** |
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340 | * {@inheritdoc} |
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341 | */ |
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342 | 15 | public function hasStateAccessor() |
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343 | { |
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344 | 15 | return null !== $this->stateAccessor; |
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345 | } |
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346 | |||
347 | /** |
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348 | * {@inheritdoc} |
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349 | */ |
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350 | 20 | public function setGraph($graph) |
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351 | { |
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352 | 20 | $this->graph = $graph; |
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353 | 20 | } |
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354 | |||
355 | /** |
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356 | * {@inheritdoc} |
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357 | */ |
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358 | 175 | public function getGraph() |
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359 | { |
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360 | 175 | return $this->graph; |
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361 | } |
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362 | |||
363 | /** |
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364 | * {@inheritDoc} |
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365 | */ |
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366 | 10 | public function findStateWithProperty($property, $value = null) |
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367 | { |
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368 | 10 | return array_keys( |
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369 | 10 | array_map( |
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370 | 2 | function (State $state) { |
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371 | 10 | return $state->getName(); |
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372 | 10 | }, |
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373 | 10 | array_filter( |
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374 | 10 | $this->states, |
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375 | 10 | function (State $state) use ($property, $value) { |
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376 | 10 | if (!$state->has($property)) { |
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377 | 10 | return false; |
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378 | } |
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379 | |||
380 | 10 | if (null !== $value && $state->get($property) !== $value) { |
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381 | 5 | return false; |
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382 | } |
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383 | |||
384 | 10 | return true; |
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385 | 6 | } |
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386 | 4 | ) |
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387 | 4 | ) |
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388 | 4 | ); |
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389 | } |
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390 | |||
391 | /** |
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392 | * Dispatches event for the transition |
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393 | * |
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394 | * @param TransitionInterface $transition |
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395 | * @param TransitionEvent $event |
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396 | * @param type $transitionState |
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397 | */ |
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398 | 50 | private function dispatchTransitionEvent(TransitionInterface $transition, TransitionEvent $event, $transitionState) |
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399 | { |
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400 | 50 | $this->dispatcher->dispatch($transitionState, $event); |
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401 | 50 | $this->dispatcher->dispatch($transitionState.'.'.$transition->getName(), $event); |
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402 | 50 | if (null !== $this->getGraph()) { |
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403 | 10 | $this->dispatcher->dispatch($transitionState.'.'.$this->getGraph().'.'.$transition->getName(), $event); |
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404 | 4 | } |
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405 | 50 | } |
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406 | } |
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407 |