Complex classes like Migrator 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 Migrator, and based on these observations, apply Extract Interface, too.
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18 | class Migrator |
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19 | { |
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20 | /** |
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21 | * @const string |
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22 | */ |
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23 | const DIRECTION_UP = 'up'; |
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24 | |||
25 | /** |
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26 | * @const string |
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27 | */ |
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28 | const DIRECTION_DOWN = 'down'; |
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29 | |||
30 | /** |
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31 | * @var string |
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32 | */ |
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33 | protected $migrationsTableName = 'migrations'; |
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34 | |||
35 | /** |
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36 | * @var string |
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37 | */ |
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38 | protected $migrationsDirectory; |
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39 | |||
40 | /** |
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41 | * @var Db |
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42 | */ |
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43 | protected $db; |
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44 | |||
45 | /** |
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46 | * @var callable |
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47 | */ |
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48 | protected $infoCallback; |
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49 | |||
50 | /** |
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51 | * @var AbstractMigration[] |
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52 | */ |
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53 | protected $migrations; |
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54 | |||
55 | /** |
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56 | * @var int[] |
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57 | */ |
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58 | protected $migratedNumbers; |
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59 | |||
60 | /** |
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61 | * @var bool |
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62 | */ |
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63 | private $hasMigrationsTable; |
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64 | |||
65 | /** |
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66 | * @param string $migrationsDirectory |
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67 | * @param Db $db |
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68 | * @param callable $infoCallback |
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69 | */ |
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70 | 10 | public function __construct( |
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79 | |||
80 | /** |
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81 | * @return \SplFileInfo[] |
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82 | */ |
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83 | 8 | protected function findMigrationFiles() |
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95 | |||
96 | /** |
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97 | * @return AbstractMigration[] |
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98 | */ |
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99 | 8 | protected function loadMigrations() |
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115 | |||
116 | /** |
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117 | * @return AbstractMigration[] |
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118 | */ |
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119 | 8 | public function getMigrations() |
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127 | |||
128 | /** |
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129 | * @return int |
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130 | */ |
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131 | 8 | public function getLatestNumber() |
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139 | |||
140 | /** |
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141 | * @return bool |
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142 | */ |
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143 | 8 | private function hasMigrationsTable() |
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152 | |||
153 | /** |
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154 | */ |
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155 | 8 | protected function createMigrationsTable() |
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168 | |||
169 | /** |
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170 | * @return array |
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171 | */ |
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172 | 8 | protected function getMigratedNumbers() |
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187 | |||
188 | /** |
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189 | * @return int |
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190 | */ |
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191 | 8 | public function getCurrentNumber() |
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198 | |||
199 | /** |
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200 | * @param int $toNumber |
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201 | * @return string |
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202 | */ |
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203 | 4 | protected function getDirection($toNumber) |
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207 | |||
208 | /** |
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209 | * @param int $to |
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210 | * @return AbstractMigration[] |
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211 | */ |
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212 | 4 | public function getMigrationsTo($to = null) |
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230 | |||
231 | /** |
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232 | * @param AbstractMigration $migration |
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233 | * @param int $toNumber |
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234 | * @param string $direction |
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235 | * @return bool |
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236 | */ |
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237 | 4 | private function shouldMigrationBeMigrated(AbstractMigration $migration, $toNumber, $direction) |
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251 | |||
252 | /** |
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253 | * @param AbstractMigration $migration |
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254 | */ |
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255 | 2 | protected function addMigratedMigration(AbstractMigration $migration) |
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266 | |||
267 | /** |
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268 | * @param AbstractMigration $migration |
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269 | */ |
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270 | 1 | protected function deleteMigratedMigration(AbstractMigration $migration) |
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283 | |||
284 | /** |
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285 | * Empty database. |
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286 | */ |
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287 | 1 | public function emptyDb() |
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297 | |||
298 | /** |
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299 | * @param int|null $to |
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300 | * @return int |
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301 | * @throws \InvalidArgumentException |
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302 | */ |
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303 | 6 | protected function getToNumber($to = null) |
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319 | |||
320 | /** |
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321 | * @param int|null $to A migration number to migrate to (if not provided, latest migration number will be used) |
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322 | * @return bool Returns true if any action was performed |
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323 | * @throws \InvalidArgumentException |
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324 | * @throws \RuntimeException |
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325 | */ |
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326 | 7 | public function migrate($to = null) |
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362 | |||
363 | /** |
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364 | * @param AbstractMigration[] $migrations |
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365 | * @param string $direction |
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366 | */ |
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367 | 3 | protected function runMigrations(array $migrations, $direction) |
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383 | |||
384 | /** |
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385 | * @param string $info |
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386 | */ |
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387 | 4 | protected function addInfo($info) |
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394 | } |
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395 |