Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Client 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. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
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 Client, and based on these observations, apply Extract Interface, too.
1 | <?php |
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57 | 1 | final class Client implements IClient |
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58 | { |
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59 | /** |
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60 | * Implement nette smart magic |
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61 | */ |
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62 | 1 | use Nette\SmartObject; |
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63 | |||
64 | /** |
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65 | * @var Closure |
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66 | */ |
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67 | public $onStart = []; |
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68 | |||
69 | /** |
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70 | * @var Closure |
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71 | */ |
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72 | public $onOpen = []; |
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73 | |||
74 | /** |
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75 | * @var Closure |
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76 | */ |
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77 | public $onConnect = []; |
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78 | |||
79 | /** |
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80 | * @var Closure |
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81 | */ |
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82 | public $onDisconnect = []; |
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83 | |||
84 | /** |
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85 | * @var Closure |
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86 | */ |
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87 | public $onClose = []; |
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88 | |||
89 | /** |
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90 | * @var Closure |
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91 | */ |
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92 | public $onPing = []; |
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93 | |||
94 | /** |
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95 | * @var Closure |
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96 | */ |
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97 | public $onPong = []; |
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98 | |||
99 | /** |
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100 | * @var Closure |
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101 | */ |
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102 | public $onPublish = []; |
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103 | |||
104 | /** |
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105 | * @var Closure |
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106 | */ |
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107 | public $onSubscribe = []; |
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108 | |||
109 | /** |
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110 | * @var Closure |
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111 | */ |
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112 | public $onUnsubscribe = []; |
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113 | |||
114 | /** |
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115 | * @var Closure |
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116 | */ |
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117 | public $onMessage = []; |
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118 | |||
119 | /** |
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120 | * @var Closure |
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121 | */ |
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122 | public $onWarning = []; |
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123 | |||
124 | /** |
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125 | * @var Closure |
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126 | */ |
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127 | public $onError = []; |
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128 | |||
129 | /** |
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130 | * @var EventLoop\LoopInterface |
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131 | */ |
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132 | private $loop; |
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133 | |||
134 | /** |
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135 | * @var Configuration\Broker |
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136 | */ |
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137 | private $configuration; |
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138 | |||
139 | /** |
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140 | * @var Socket\ConnectorInterface |
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141 | */ |
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142 | private $connector; |
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143 | |||
144 | /** |
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145 | * @var Socket\ConnectionInterface|NULL |
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146 | */ |
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147 | private $stream = NULL; |
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148 | |||
149 | /** |
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150 | * @var Mqtt\Connection |
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151 | */ |
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152 | private $connection; |
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153 | |||
154 | /** |
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155 | * @var Mqtt\StreamParser |
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156 | */ |
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157 | private $parser; |
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158 | |||
159 | /** |
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160 | * @var Mqtt\IdentifierGenerator |
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161 | */ |
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162 | private $identifierGenerator; |
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163 | |||
164 | /** |
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165 | * @var bool |
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166 | */ |
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167 | private $isConnected = FALSE; |
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168 | |||
169 | /** |
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170 | * @var bool |
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171 | */ |
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172 | private $isConnecting = FALSE; |
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173 | |||
174 | /** |
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175 | * @var bool |
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176 | */ |
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177 | private $isDisconnecting = FALSE; |
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178 | |||
179 | /** |
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180 | * @var string |
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181 | */ |
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182 | private $host; |
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183 | |||
184 | /** |
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185 | * @var int |
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186 | */ |
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187 | private $port; |
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188 | |||
189 | /** |
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190 | * @var int |
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191 | */ |
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192 | private $timeout = 5; |
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193 | |||
194 | /** |
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195 | * @var Flow\Envelope[] |
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196 | */ |
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197 | private $receivingFlows = []; |
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198 | |||
199 | /** |
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200 | * @var Flow\Envelope[] |
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201 | */ |
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202 | private $sendingFlows = []; |
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203 | |||
204 | /** |
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205 | * @var Flow\Envelope |
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206 | */ |
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207 | private $writtenFlow; |
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208 | |||
209 | /** |
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210 | * @var EventLoop\TimerInterface[] |
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211 | */ |
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212 | private $timer = []; |
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213 | |||
214 | /** |
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215 | * @var Mqtt\Message|NULL |
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216 | */ |
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217 | private $lastMessage = NULL; |
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218 | |||
219 | /** |
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220 | * @param EventLoop\LoopInterface $eventLoop |
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221 | * @param Configuration\Broker $configuration |
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222 | * @param Mqtt\IdentifierGenerator|NULL $identifierGenerator |
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223 | * @param Mqtt\StreamParser|NULL $parser |
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224 | */ |
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225 | public function __construct( |
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252 | |||
253 | /** |
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254 | * {@inheritdoc} |
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255 | */ |
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256 | public function setLoop(EventLoop\LoopInterface $loop) : void |
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267 | |||
268 | /** |
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269 | * {@inheritdoc} |
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270 | */ |
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271 | public function getLoop() : EventLoop\LoopInterface |
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275 | |||
276 | /** |
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277 | * {@inheritdoc} |
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278 | * |
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279 | * @throws Exceptions\InvalidStateException |
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280 | */ |
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281 | public function setConfiguration(Configuration\Broker $configuration) : void |
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289 | |||
290 | /** |
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291 | * {@inheritdoc} |
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292 | * |
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293 | * @throws Exceptions\InvalidStateException |
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294 | */ |
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295 | public function getUri() : string |
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299 | |||
300 | /** |
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301 | * {@inheritdoc} |
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302 | */ |
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303 | public function getPort() : int |
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307 | |||
308 | /** |
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309 | * {@inheritdoc} |
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310 | */ |
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311 | public function isConnected() : bool |
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315 | |||
316 | /** |
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317 | * {@inheritdoc} |
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318 | */ |
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319 | public function connect() : Promise\ExtendedPromiseInterface |
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379 | |||
380 | /** |
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381 | * {@inheritdoc} |
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382 | */ |
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383 | public function disconnect() : Promise\ExtendedPromiseInterface |
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413 | |||
414 | /** |
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415 | * {@inheritdoc} |
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416 | */ |
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417 | View Code Duplication | public function subscribe(Mqtt\Subscription $subscription) : Promise\ExtendedPromiseInterface |
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425 | |||
426 | /** |
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427 | * {@inheritdoc} |
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428 | */ |
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429 | View Code Duplication | public function unsubscribe(Mqtt\Subscription $subscription) : Promise\ExtendedPromiseInterface |
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437 | |||
438 | /** |
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439 | * {@inheritdoc} |
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440 | */ |
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441 | public function publish(Mqtt\Message $message) : Promise\ExtendedPromiseInterface |
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449 | |||
450 | /** |
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451 | * {@inheritdoc} |
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452 | */ |
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453 | public function publishPeriodically( |
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478 | |||
479 | /** |
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480 | * Establishes a network connection to a server |
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481 | * |
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482 | * @return Promise\ExtendedPromiseInterface |
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483 | * |
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484 | * @throws Exceptions\InvalidStateException |
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485 | */ |
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486 | private function establishConnection() : Promise\ExtendedPromiseInterface |
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521 | |||
522 | /** |
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523 | * Registers a new client with the broker |
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524 | * |
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525 | * @param Mqtt\Connection $connection |
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526 | * |
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527 | * @return Promise\ExtendedPromiseInterface |
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528 | */ |
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529 | private function registerClient(Mqtt\Connection $connection) : Promise\ExtendedPromiseInterface |
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556 | |||
557 | /** |
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558 | * Handles incoming data |
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559 | * |
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560 | * @param string $data |
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561 | * |
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562 | * @return void |
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563 | */ |
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564 | private function handleReceive(string $data) : void |
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582 | |||
583 | /** |
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584 | * Handles an incoming packet |
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585 | * |
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586 | * @param Mqtt\Packet $packet |
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587 | * |
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588 | * @return void |
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589 | */ |
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590 | private function handlePacket(Mqtt\Packet $packet) : void |
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640 | |||
641 | /** |
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642 | * Handles outgoing packets |
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643 | * |
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644 | * @return void |
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645 | */ |
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646 | private function handleSend() : void |
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671 | |||
672 | /** |
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673 | * Handles closing of the stream |
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674 | * |
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675 | * @return void |
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676 | */ |
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677 | private function handleClose() : void |
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695 | |||
696 | /** |
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697 | * Handles errors of the stream |
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698 | * |
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699 | * @param \Exception $ex |
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700 | * |
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701 | * @return void |
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702 | */ |
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703 | private function handleError(\Exception $ex) : void |
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707 | |||
708 | /** |
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709 | * Starts the given flow |
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710 | * |
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711 | * @param Mqtt\Flow $flow |
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712 | * @param bool $isSilent |
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713 | * |
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714 | * @return Promise\ExtendedPromiseInterface |
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715 | */ |
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716 | private function startFlow(Mqtt\Flow $flow, bool $isSilent = FALSE) : Promise\ExtendedPromiseInterface |
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749 | |||
750 | /** |
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751 | * Continues the given flow |
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752 | * |
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753 | * @param Flow\Envelope $flow |
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754 | * @param Mqtt\Packet $packet |
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755 | * |
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756 | * @return void |
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757 | */ |
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758 | private function continueFlow(Flow\Envelope $flow, Mqtt\Packet $packet) : void |
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786 | |||
787 | /** |
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788 | * Finishes the given flow |
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789 | * |
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790 | * @param Flow\Envelope $flow |
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791 | * |
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792 | * @return void |
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793 | */ |
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794 | private function finishFlow(Flow\Envelope $flow) : void |
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857 | |||
858 | /** |
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859 | * @return void |
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860 | */ |
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861 | private function createConnector() : void |
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875 | } |
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876 |
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: