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 QRCode 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 QRCode, and based on these observations, apply Extract Interface, too.
1 | <?php |
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25 | class QRCode{ |
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26 | |||
27 | /** |
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28 | * API constants |
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29 | */ |
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30 | const OUTPUT_STRING_TEXT = 0; |
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31 | const OUTPUT_STRING_JSON = 1; |
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32 | const OUTPUT_STRING_HTML = 2; |
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33 | |||
34 | const OUTPUT_IMAGE_PNG = 'png'; |
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35 | const OUTPUT_IMAGE_JPG = 'jpg'; |
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36 | const OUTPUT_IMAGE_GIF = 'gif'; |
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37 | |||
38 | const ERROR_CORRECT_LEVEL_L = 1; // 7%. |
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39 | const ERROR_CORRECT_LEVEL_M = 0; // 15%. |
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40 | const ERROR_CORRECT_LEVEL_Q = 3; // 25%. |
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41 | const ERROR_CORRECT_LEVEL_H = 2; // 30%. |
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42 | |||
43 | // max bits @ ec level L:07 M:15 Q:25 H:30 % |
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44 | const TYPE_01 = 1; // 152 128 104 72 |
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45 | const TYPE_02 = 2; // 272 224 176 128 |
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46 | const TYPE_03 = 3; // 440 352 272 208 |
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47 | const TYPE_04 = 4; // 640 512 384 288 |
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48 | const TYPE_05 = 5; // 864 688 496 368 |
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49 | const TYPE_06 = 6; // 1088 864 608 480 |
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50 | const TYPE_07 = 7; // 1248 992 704 528 |
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51 | const TYPE_08 = 8; // 1552 1232 880 688 |
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52 | const TYPE_09 = 9; // 1856 1456 1056 800 |
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53 | const TYPE_10 = 10; // 2192 1728 1232 976 |
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54 | |||
55 | /** |
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56 | * @var array |
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57 | */ |
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58 | protected $matrix = []; |
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59 | |||
60 | /** |
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61 | * @var int |
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62 | */ |
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63 | protected $pixelCount = 0; |
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64 | |||
65 | /** |
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66 | * @var int |
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67 | */ |
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68 | protected $typeNumber; |
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69 | |||
70 | /** |
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71 | * @var int |
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72 | */ |
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73 | protected $errorCorrectLevel; |
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74 | |||
75 | /** |
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76 | * @var \chillerlan\QRCode\BitBuffer |
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77 | */ |
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78 | protected $bitBuffer; |
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79 | |||
80 | /** |
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81 | * @var \chillerlan\QRCode\Data\QRDataInterface |
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82 | */ |
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83 | protected $qrDataInterface; |
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84 | |||
85 | /** |
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86 | * @var \chillerlan\QRCode\Output\QROutputInterface |
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87 | */ |
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88 | protected $qrOutputInterface; |
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89 | |||
90 | /** |
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91 | * QRCode constructor. |
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92 | * |
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93 | * @param string $data |
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94 | * @param \chillerlan\QRCode\Output\QROutputInterface $output |
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95 | * @param \chillerlan\QRCode\QROptions|null $options |
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96 | */ |
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97 | public function __construct($data, QROutputInterface $output, QROptions $options = null){ |
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102 | |||
103 | /** |
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104 | * @param string $data |
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105 | * @param \chillerlan\QRCode\QROptions|null $options |
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106 | * |
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107 | * @return $this |
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108 | * @throws \chillerlan\QRCode\QRCodeException |
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109 | */ |
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110 | public function setData($data, QROptions $options = null){ |
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111 | $data = trim($data); |
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112 | |||
113 | if(empty($data)){ |
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114 | throw new QRCodeException('No data given.'); |
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115 | } |
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116 | |||
117 | if(!$options instanceof QROptions){ |
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118 | $options = new QROptions; |
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119 | } |
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120 | |||
121 | if(!in_array($options->errorCorrectLevel, QRConst::RSBLOCK, true)){ |
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122 | throw new QRCodeException('Invalid error correct level: '.$options->errorCorrectLevel); |
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123 | } |
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124 | |||
125 | $this->errorCorrectLevel = $options->errorCorrectLevel; |
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126 | |||
127 | switch(true){ |
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128 | case Util::isAlphaNum($data): |
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129 | $mode = Util::isNumber($data) ? QRConst::MODE_NUMBER : QRConst::MODE_ALPHANUM; |
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130 | break; |
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131 | case Util::isKanji($data): |
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132 | $mode = QRConst::MODE_KANJI; |
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133 | break; |
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134 | default: |
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135 | $mode = QRConst::MODE_BYTE; |
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136 | break; |
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137 | } |
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138 | |||
139 | $qrDataInterface = [ |
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140 | QRConst::MODE_ALPHANUM => AlphaNum::class, |
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141 | QRConst::MODE_BYTE => Byte::class, |
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142 | QRConst::MODE_KANJI => Kanji::class, |
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143 | QRConst::MODE_NUMBER => Number::class, |
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144 | ][$mode]; |
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145 | |||
146 | $this->qrDataInterface = new $qrDataInterface($data); |
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147 | $this->typeNumber = intval($options->typeNumber); |
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148 | |||
149 | if($this->typeNumber < 1 || $this->typeNumber > 10){ |
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150 | $this->typeNumber = $this->getTypeNumber($mode); |
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151 | } |
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152 | |||
153 | return $this; |
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154 | } |
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155 | |||
156 | /** |
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157 | * @param $mode |
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158 | * |
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159 | * @return int |
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160 | * @throws \chillerlan\QRCode\QRCodeException |
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161 | */ |
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162 | protected function getTypeNumber($mode){ |
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163 | $length = $this->qrDataInterface->dataLength; |
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164 | |||
165 | if($this->qrDataInterface->mode === QRConst::MODE_KANJI){ |
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166 | $length = floor($this->qrDataInterface->dataLength / 2); |
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167 | } |
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168 | |||
169 | foreach(range(1, 10) as $type){ |
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170 | if($length <= Util::getMaxLength($type, $mode, $this->errorCorrectLevel)){ |
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171 | return $type; |
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172 | } |
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173 | } |
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174 | |||
175 | throw new QRCodeException('Unable to determine type number.'); // @codeCoverageIgnore |
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176 | } |
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177 | |||
178 | /** |
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179 | * @return mixed |
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180 | */ |
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181 | public function output(){ |
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185 | |||
186 | /** |
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187 | * @return array |
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188 | */ |
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189 | public function getRawData(){ |
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305 | |||
306 | /** |
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307 | * @param bool $test |
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308 | */ |
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309 | protected function setTypeNumber($test){ |
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320 | |||
321 | /** |
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322 | * @param bool $test |
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323 | * @param int $pattern |
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324 | */ |
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325 | protected function setTypeInfo($test, $pattern){ |
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350 | |||
351 | /** |
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352 | * @throws \chillerlan\QRCode\QRCodeException |
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353 | */ |
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354 | protected function createData(){ |
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399 | |||
400 | /** |
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401 | * @return array |
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402 | * @throws \chillerlan\QRCode\QRCodeException |
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403 | */ |
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404 | protected function createBytes(){ |
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474 | |||
475 | /** |
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476 | * @param int $pattern |
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477 | * |
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478 | * @throws \chillerlan\QRCode\QRCodeException |
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479 | */ |
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480 | protected function mapData($pattern){ |
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544 | |||
545 | /** |
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546 | * @throws \chillerlan\QRCode\QRCodeException |
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547 | */ |
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548 | protected function setPattern(){ |
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606 | |||
607 | /** |
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608 | * @param bool $test |
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609 | * @param int $maskPattern |
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610 | * |
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611 | * @throws \chillerlan\QRCode\QRCodeException |
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612 | */ |
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613 | protected function getMatrix($test, $maskPattern){ |
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624 | |||
625 | } |
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626 |
If you access a property on an interface, you most likely code against a concrete implementation of the interface.
Available Fixes
Adding an additional type check:
Changing the type hint: