Complex classes like Reader 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 Reader, and based on these observations, apply Extract Interface, too.
1 | <?php |
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50 | class Reader extends AbstractCsv implements Countable, IteratorAggregate, JsonSerializable |
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51 | { |
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52 | /** |
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53 | * header offset. |
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54 | * |
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55 | * @var int|null |
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56 | */ |
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57 | protected $header_offset; |
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58 | |||
59 | /** |
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60 | * header record. |
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61 | * |
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62 | * @var string[] |
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63 | */ |
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64 | protected $header = []; |
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65 | |||
66 | /** |
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67 | * records count. |
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68 | * |
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69 | * @var int |
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70 | */ |
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71 | protected $nb_records = -1; |
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72 | |||
73 | /** |
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74 | * {@inheritdoc} |
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75 | */ |
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76 | protected $stream_filter_mode = STREAM_FILTER_READ; |
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77 | |||
78 | /** |
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79 | * {@inheritdoc} |
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80 | */ |
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81 | 3 | public static function createFromPath(string $path, string $open_mode = 'r', $context = null) |
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82 | { |
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83 | 3 | return parent::createFromPath($path, $open_mode, $context); |
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84 | } |
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85 | |||
86 | /** |
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87 | * {@inheritdoc} |
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88 | */ |
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89 | 27 | protected function resetProperties() |
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90 | { |
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91 | 27 | parent::resetProperties(); |
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92 | 27 | $this->nb_records = -1; |
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93 | 27 | $this->header = []; |
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94 | 27 | } |
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95 | |||
96 | /** |
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97 | * Returns the header offset. |
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98 | * |
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99 | * If no CSV header offset is set this method MUST return null |
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100 | * |
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101 | * @return int|null |
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102 | */ |
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103 | 15 | public function getHeaderOffset() |
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104 | { |
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105 | 15 | return $this->header_offset; |
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106 | } |
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107 | |||
108 | /** |
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109 | * Returns the CSV record used as header. |
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110 | * |
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111 | * The returned header is represented as an array of string values |
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112 | * |
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113 | * @return string[] |
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114 | */ |
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115 | 21 | public function getHeader(): array |
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116 | { |
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117 | 21 | if (null === $this->header_offset) { |
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118 | 15 | return $this->header; |
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119 | } |
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120 | |||
121 | 9 | if ([] !== $this->header) { |
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122 | 3 | return $this->header; |
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123 | } |
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124 | |||
125 | 9 | $this->header = $this->setHeader($this->header_offset); |
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126 | |||
127 | 6 | return $this->header; |
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128 | } |
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129 | |||
130 | /** |
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131 | * Determine the CSV record header. |
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132 | * |
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133 | * @throws Exception If the header offset is set and no record is found or is the empty array |
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134 | * |
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135 | * @return string[] |
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136 | */ |
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137 | 12 | protected function setHeader(int $offset): array |
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138 | { |
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139 | 12 | $header = $this->seekRow($offset); |
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140 | 12 | if (false === $header || [] === $header) { |
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141 | 6 | throw new Exception(sprintf('The header record does not exist or is empty at offset: `%s`', $offset)); |
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142 | } |
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143 | |||
144 | 6 | if (0 === $offset) { |
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145 | 3 | return $this->removeBOM($header, mb_strlen($this->getInputBOM()), $this->enclosure); |
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146 | } |
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147 | |||
148 | 3 | return $header; |
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149 | } |
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150 | |||
151 | /** |
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152 | * Returns the row at a given offset. |
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153 | * |
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154 | * @return array|false |
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155 | */ |
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156 | 12 | protected function seekRow(int $offset) |
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157 | { |
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158 | 12 | foreach ($this->getDocument() as $index => $record) { |
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159 | 12 | if ($offset === $index) { |
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160 | 9 | return $record; |
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161 | } |
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162 | } |
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163 | |||
164 | 9 | return false; |
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165 | } |
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166 | |||
167 | /** |
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168 | * Returns the document as an Iterator. |
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169 | */ |
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170 | 18 | protected function getDocument(): Iterator |
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171 | { |
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172 | 18 | if (70400 > PHP_VERSION_ID && '' === $this->escape) { |
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173 | 6 | $this->document->setCsvControl($this->delimiter, $this->enclosure); |
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174 | |||
175 | 6 | return EmptyEscapeParser::parse($this->document); |
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176 | } |
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177 | |||
178 | 12 | $this->document->setFlags(SplFileObject::READ_CSV | SplFileObject::READ_AHEAD | SplFileObject::SKIP_EMPTY); |
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179 | 12 | $this->document->setCsvControl($this->delimiter, $this->enclosure, $this->escape); |
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180 | 12 | $this->document->rewind(); |
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181 | |||
182 | 12 | return $this->document; |
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183 | } |
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184 | |||
185 | /** |
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186 | * Strip the BOM sequence from a record. |
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187 | * |
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188 | * @param string[] $record |
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189 | * |
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190 | * @return string[] |
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191 | */ |
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192 | 12 | protected function removeBOM(array $record, int $bom_length, string $enclosure): array |
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193 | { |
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194 | 12 | if (0 === $bom_length) { |
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195 | 3 | return $record; |
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196 | } |
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197 | |||
198 | 9 | $record[0] = mb_substr($record[0], $bom_length); |
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199 | 9 | if ($enclosure.$enclosure != substr($record[0].$record[0], strlen($record[0]) - 1, 2)) { |
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200 | 6 | return $record; |
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201 | } |
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202 | |||
203 | 3 | $record[0] = substr($record[0], 1, -1); |
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204 | |||
205 | 3 | return $record; |
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206 | } |
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207 | |||
208 | /** |
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209 | * {@inheritdoc} |
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210 | */ |
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211 | 9 | public function __call($method, array $arguments) |
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212 | { |
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213 | 9 | static $whitelisted = ['fetchColumn' => 1, 'fetchOne' => 1, 'fetchPairs' => 1]; |
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214 | 9 | if (isset($whitelisted[$method])) { |
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215 | 3 | return (new ResultSet($this->getRecords(), $this->getHeader()))->$method(...$arguments); |
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216 | } |
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217 | |||
218 | 6 | throw new BadMethodCallException(sprintf('%s::%s() method does not exist', static::class, $method)); |
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219 | } |
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220 | |||
221 | /** |
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222 | * {@inheritdoc} |
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223 | */ |
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224 | 3 | public function count(): int |
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225 | { |
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226 | 3 | if (-1 === $this->nb_records) { |
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227 | 3 | $this->nb_records = iterator_count($this->getRecords()); |
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228 | } |
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229 | |||
230 | 3 | return $this->nb_records; |
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231 | } |
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232 | |||
233 | /** |
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234 | * {@inheritdoc} |
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235 | */ |
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236 | 6 | public function getIterator(): Iterator |
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237 | { |
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238 | 6 | return $this->getRecords(); |
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239 | } |
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240 | |||
241 | /** |
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242 | * {@inheritdoc} |
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243 | */ |
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244 | 3 | public function jsonSerialize(): array |
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245 | { |
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246 | 3 | return iterator_to_array($this->getRecords(), false); |
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247 | } |
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248 | |||
249 | /** |
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250 | * Returns the CSV records as an iterator object. |
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251 | * |
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252 | * Each CSV record is represented as a simple array containing strings or null values. |
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253 | * |
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254 | * If the CSV document has a header record then each record is combined |
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255 | * to the header record and the header record is removed from the iterator. |
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256 | * |
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257 | * If the CSV document is inconsistent. Missing record fields are |
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258 | * filled with null values while extra record fields are strip from |
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259 | * the returned object. |
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260 | * |
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261 | * @param string[] $header an optional header to use instead of the CSV document header |
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262 | */ |
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263 | 21 | public function getRecords(array $header = []): Iterator |
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264 | { |
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265 | 21 | $header = $this->computeHeader($header); |
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266 | 18 | $normalized = static function ($record): bool { |
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267 | 18 | return is_array($record) && $record != [null]; |
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268 | 18 | }; |
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269 | |||
270 | 18 | $bom = ''; |
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271 | 18 | if ($this->is_enable_BOM_stripping) { |
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272 | 15 | $bom = $this->getInputBOM(); |
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273 | } |
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274 | |||
275 | 18 | $document = $this->getDocument(); |
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276 | 18 | $records = $this->stripBOM(new CallbackFilterIterator($document, $normalized), $bom); |
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277 | 18 | if (null !== $this->header_offset) { |
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278 | 6 | $records = new CallbackFilterIterator($records, function (array $record, int $offset): bool { |
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279 | 6 | return $offset !== $this->header_offset; |
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280 | 6 | }); |
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281 | } |
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282 | |||
283 | 18 | return $this->combineHeader($records, $header); |
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284 | } |
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285 | |||
286 | /** |
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287 | * Returns the header to be used for iteration. |
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288 | * |
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289 | * @param string[] $header |
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290 | * |
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291 | * @throws Exception If the header contains non unique column name |
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292 | * |
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293 | * @return string[] |
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294 | */ |
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295 | 27 | protected function computeHeader(array $header) |
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307 | |||
308 | /** |
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309 | * Combine the CSV header to each record if present. |
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310 | * |
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311 | * @param string[] $header |
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312 | */ |
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313 | 33 | protected function combineHeader(Iterator $iterator, array $header): Iterator |
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330 | |||
331 | /** |
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332 | * Strip the BOM sequence from the returned records if necessary. |
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333 | */ |
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334 | 27 | protected function stripBOM(Iterator $iterator, string $bom): Iterator |
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351 | |||
352 | /** |
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353 | * Selects the record to be used as the CSV header. |
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354 | * |
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355 | * Because the header is represented as an array, to be valid |
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356 | * a header MUST contain only unique string value. |
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357 | * |
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358 | * @param int|null $offset the header record offset |
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359 | * |
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360 | * @throws Exception if the offset is a negative integer |
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361 | * |
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362 | * @return static |
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363 | */ |
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364 | 24 | public function setHeaderOffset($offset): self |
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383 | } |
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384 |