Complex classes like Csv 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 Csv, and based on these observations, apply Extract Interface, too.
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18 | class Csv implements Iterator |
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19 | { |
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20 | |||
21 | /** |
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22 | * File handler |
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23 | * @var resource |
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24 | */ |
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25 | protected $handle; |
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26 | |||
27 | /** |
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28 | * Current CSV line |
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29 | * @var string |
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30 | */ |
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31 | protected $line; |
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32 | |||
33 | /** |
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34 | * @var int |
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35 | */ |
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36 | protected $key; |
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37 | |||
38 | /** |
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39 | * Current offset in bytes |
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40 | * @var integer |
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41 | */ |
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42 | protected $position; |
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43 | |||
44 | /** |
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45 | * Total CSV file size in bytes |
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46 | * @var integer |
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47 | */ |
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48 | protected $total; |
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49 | |||
50 | /** |
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51 | * Path to CSV file |
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52 | * @var string |
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53 | */ |
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54 | protected $file; |
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55 | |||
56 | /** |
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57 | * Max number of rows to parse |
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58 | * @var integer |
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59 | */ |
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60 | protected $limit; |
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61 | |||
62 | /** |
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63 | * Final offset in bytes |
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64 | * @var integer |
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65 | */ |
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66 | protected $last = 0; |
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67 | |||
68 | /** |
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69 | * Starting offset in bytes |
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70 | * @var integer |
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71 | */ |
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72 | protected $offset = 0; |
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73 | |||
74 | /** |
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75 | * Array of header names |
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76 | * @var array |
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77 | */ |
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78 | protected $header = array(); |
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79 | |||
80 | /** |
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81 | * Skip or not first line |
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82 | * @var boolean |
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83 | */ |
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84 | protected $skip_header = false; |
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85 | |||
86 | /** |
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87 | * CSV delimiter |
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88 | * @var string |
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89 | */ |
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90 | protected $delimiter = ","; |
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91 | |||
92 | /** |
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93 | * Constructor |
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94 | */ |
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95 | public function __construct() |
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99 | |||
100 | /** |
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101 | * Closes file handler |
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102 | */ |
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103 | public function __destruct() |
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109 | |||
110 | /** |
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111 | * Sets file to parse |
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112 | * @param string $file |
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113 | * @param integer $filesize |
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114 | * @return $this |
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115 | */ |
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116 | public function open($file, $filesize = null) |
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128 | |||
129 | /** |
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130 | * Sets max lines to parse |
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131 | * @param integer $limit |
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132 | * @return $this |
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133 | */ |
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134 | public function setLimit($limit) |
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139 | |||
140 | /** |
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141 | * Sets separator between columns |
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142 | * @param string $character |
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143 | * @return $this |
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144 | */ |
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145 | public function setDelimiter($character) |
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150 | |||
151 | /** |
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152 | * Get first line of CSV file |
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153 | * @return array |
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154 | */ |
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155 | public function getHeader() |
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162 | |||
163 | /** |
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164 | * Sets header (first line) |
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165 | * @param array $header |
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166 | * @return $this |
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167 | */ |
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168 | public function setHeader(array $header) |
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173 | |||
174 | /** |
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175 | * CSV reader |
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176 | * @return array |
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177 | */ |
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178 | public function read() |
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288 | |||
289 | /** |
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290 | * Moves pointer to a certain position |
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291 | * @param integer $position |
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292 | */ |
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293 | public function rewind($position = 0) |
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300 | |||
301 | /** |
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302 | * Sets current string and offset |
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303 | * @return null|integer |
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304 | */ |
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305 | public function next() |
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315 | |||
316 | /** |
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317 | * Determines if CSV line is valid |
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318 | * @return boolean |
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319 | */ |
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320 | public function valid() |
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324 | |||
325 | /** |
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326 | * Gets current CSV row |
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327 | * @return string |
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328 | */ |
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329 | public function current() |
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333 | |||
334 | /** |
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335 | * Row key |
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336 | * @return int |
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337 | */ |
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338 | public function key() |
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342 | |||
343 | /** |
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344 | * Gets current offset in bytes |
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345 | * @return integer |
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346 | */ |
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347 | public function getPosition() |
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351 | |||
352 | /** |
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353 | * Get latest file pointer offset in bytes |
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354 | * @return integer |
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355 | */ |
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356 | public function getOffset() |
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360 | |||
361 | /** |
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362 | * Sets initial file offset in bytes |
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363 | * @param integer $offset |
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364 | * @return $this |
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365 | */ |
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366 | public function setOffset($offset) |
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371 | |||
372 | /** |
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373 | * Force to skip first row (header) |
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374 | * @return $this |
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375 | */ |
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376 | public function skipHeader() |
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381 | |||
382 | /** |
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383 | * Parses CSV into multidimensional array |
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384 | * @return array |
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385 | */ |
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386 | public function parse() |
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394 | |||
395 | } |
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396 |