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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| 41 | class Reader extends AbstractCsv implements TabularDataReader, JsonSerializable |
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| 42 | { |
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| 43 | /** |
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| 44 | * header offset. |
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| 45 | * |
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| 46 | * @var int|null |
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| 47 | */ |
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| 48 | protected $header_offset; |
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| 49 | |||
| 50 | /** |
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| 51 | * header record. |
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| 52 | * |
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| 53 | * @var string[] |
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| 54 | */ |
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| 55 | protected $header = []; |
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| 56 | |||
| 57 | /** |
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| 58 | * records count. |
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| 59 | * |
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| 60 | * @var int |
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| 61 | */ |
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| 62 | protected $nb_records = -1; |
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| 63 | |||
| 64 | /** |
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| 65 | * {@inheritdoc} |
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| 66 | */ |
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| 67 | protected $stream_filter_mode = STREAM_FILTER_READ; |
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| 68 | |||
| 69 | /** |
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| 70 | * @var bool |
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| 71 | */ |
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| 72 | protected $is_empty_records_included = false; |
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| 73 | |||
| 74 | /** |
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| 75 | * {@inheritdoc} |
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| 76 | */ |
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| 77 | 3 | public static function createFromPath(string $path, string $open_mode = 'r', $context = null) |
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| 78 | { |
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| 79 | 3 | return parent::createFromPath($path, $open_mode, $context); |
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| 80 | } |
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| 81 | |||
| 82 | /** |
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| 83 | * {@inheritdoc} |
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| 84 | */ |
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| 85 | 30 | protected function resetProperties(): void |
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| 86 | { |
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| 87 | 30 | parent::resetProperties(); |
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| 88 | 30 | $this->nb_records = -1; |
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| 89 | 30 | $this->header = []; |
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| 90 | 30 | } |
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| 91 | |||
| 92 | /** |
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| 93 | * Returns the header offset. |
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| 94 | * |
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| 95 | * If no CSV header offset is set this method MUST return null |
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| 96 | * |
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| 97 | */ |
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| 98 | 21 | public function getHeaderOffset(): ?int |
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| 99 | { |
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| 100 | 21 | return $this->header_offset; |
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| 101 | } |
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| 102 | |||
| 103 | /** |
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| 104 | * {@inheritDoc} |
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| 105 | */ |
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| 106 | 24 | public function getHeader(): array |
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| 107 | { |
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| 108 | 24 | if (null === $this->header_offset) { |
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| 109 | 18 | return $this->header; |
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| 110 | } |
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| 111 | |||
| 112 | 9 | if ([] !== $this->header) { |
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| 113 | 3 | return $this->header; |
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| 114 | } |
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| 115 | |||
| 116 | 9 | $this->header = $this->setHeader($this->header_offset); |
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| 117 | |||
| 118 | 6 | return $this->header; |
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| 119 | } |
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| 120 | |||
| 121 | /** |
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| 122 | * Determine the CSV record header. |
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| 123 | * |
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| 124 | * @throws Exception If the header offset is set and no record is found or is the empty array |
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| 125 | * |
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| 126 | * @return string[] |
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| 127 | */ |
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| 128 | 12 | protected function setHeader(int $offset): array |
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| 129 | { |
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| 130 | 12 | $header = $this->seekRow($offset); |
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| 131 | 12 | if (in_array($header, [[], [null]], true)) { |
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| 132 | 6 | throw new SyntaxError(sprintf('The header record does not exist or is empty at offset: `%s`', $offset)); |
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| 133 | } |
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| 134 | |||
| 135 | 6 | if (0 === $offset) { |
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| 136 | 3 | return $this->removeBOM($header, mb_strlen($this->getInputBOM()), $this->enclosure); |
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| 137 | } |
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| 138 | |||
| 139 | 3 | return $header; |
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| 140 | } |
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| 141 | |||
| 142 | /** |
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| 143 | * Returns the row at a given offset. |
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| 144 | */ |
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| 145 | 12 | protected function seekRow(int $offset): array |
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| 146 | { |
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| 147 | 12 | foreach ($this->getDocument() as $index => $record) { |
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| 148 | 12 | if ($offset === $index) { |
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| 149 | 6 | return $record; |
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| 150 | } |
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| 151 | } |
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| 152 | |||
| 153 | 6 | return []; |
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| 154 | } |
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| 155 | |||
| 156 | /** |
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| 157 | * Returns the document as an Iterator. |
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| 158 | */ |
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| 159 | 21 | protected function getDocument(): Iterator |
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| 160 | { |
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| 161 | 21 | if (70400 > PHP_VERSION_ID && '' === $this->escape) { |
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| 162 | 6 | $this->document->setCsvControl($this->delimiter, $this->enclosure); |
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| 163 | |||
| 164 | 6 | return EmptyEscapeParser::parse($this->document); |
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| 165 | } |
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| 166 | |||
| 167 | 15 | $this->document->setFlags(SplFileObject::READ_CSV | SplFileObject::READ_AHEAD); |
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| 168 | 15 | $this->document->setCsvControl($this->delimiter, $this->enclosure, $this->escape); |
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| 169 | 15 | $this->document->rewind(); |
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| 170 | |||
| 171 | 15 | return $this->document; |
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| 172 | } |
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| 173 | |||
| 174 | /** |
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| 175 | * Strip the BOM sequence from a record. |
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| 176 | * |
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| 177 | * @param string[] $record |
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| 178 | * |
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| 179 | * @return string[] |
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| 180 | */ |
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| 181 | 12 | protected function removeBOM(array $record, int $bom_length, string $enclosure): array |
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| 182 | { |
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| 183 | 12 | if (0 === $bom_length) { |
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| 184 | 3 | return $record; |
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| 185 | } |
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| 186 | |||
| 187 | 9 | $record[0] = mb_substr($record[0], $bom_length); |
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| 188 | 9 | if ($enclosure.$enclosure != substr($record[0].$record[0], strlen($record[0]) - 1, 2)) { |
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| 189 | 6 | return $record; |
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| 190 | } |
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| 191 | |||
| 192 | 3 | $record[0] = substr($record[0], 1, -1); |
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| 193 | |||
| 194 | 3 | return $record; |
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| 195 | } |
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| 196 | |||
| 197 | /** |
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| 198 | * {@inheritdoc} |
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| 199 | */ |
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| 200 | 3 | public function fetchColumn($index = 0): Iterator |
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| 201 | { |
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| 202 | 3 | $tabular_data = new ResultSet($this->getRecords(), $this->getHeader()); |
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| 203 | |||
| 204 | 3 | return $tabular_data->fetchColumn($index); |
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| 205 | } |
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| 206 | |||
| 207 | /** |
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| 208 | * {@inheritdoc} |
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| 209 | */ |
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| 210 | 3 | public function fetchOne(int $nth_record = 0): array |
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| 211 | { |
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| 212 | 3 | $tabular_data = new ResultSet($this->getRecords(), $this->getHeader()); |
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| 213 | |||
| 214 | 3 | return $tabular_data->fetchOne($nth_record); |
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| 215 | } |
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| 216 | |||
| 217 | /** |
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| 218 | * {@inheritdoc} |
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| 219 | */ |
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| 220 | 3 | public function fetchPairs($offset_index = 0, $value_index = 1): Iterator |
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| 221 | { |
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| 222 | 3 | $tabular_data = new ResultSet($this->getRecords(), $this->getHeader()); |
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| 223 | |||
| 224 | 3 | return $tabular_data->fetchPairs($offset_index, $value_index); |
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| 225 | } |
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| 226 | |||
| 227 | /** |
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| 228 | * {@inheritdoc} |
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| 229 | */ |
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| 230 | 3 | public function count(): int |
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| 238 | |||
| 239 | /** |
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| 240 | * {@inheritdoc} |
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| 241 | */ |
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| 242 | 6 | public function getIterator(): Iterator |
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| 246 | |||
| 247 | /** |
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| 248 | * {@inheritdoc} |
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| 249 | */ |
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| 250 | 3 | public function jsonSerialize(): array |
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| 254 | |||
| 255 | /** |
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| 256 | * Returns the CSV records as an iterator object. |
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| 257 | * |
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| 258 | * Each CSV record is represented as a simple array containing strings or null values. |
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| 259 | * |
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| 260 | * If the CSV document has a header record then each record is combined |
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| 261 | * to the header record and the header record is removed from the iterator. |
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| 262 | * |
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| 263 | * If the CSV document is inconsistent. Missing record fields are |
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| 264 | * filled with null values while extra record fields are strip from |
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| 265 | * the returned object. |
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| 266 | * |
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| 267 | * @param string[] $header an optional header to use instead of the CSV document header |
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| 268 | */ |
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| 269 | 36 | public function getRecords(array $header = []): Iterator |
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| 270 | { |
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| 271 | 36 | $header = $this->computeHeader($header); |
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| 272 | $normalized = function ($record): bool { |
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| 273 | 33 | return is_array($record) && ($this->is_empty_records_included || $record != [null]); |
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| 274 | 33 | }; |
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| 275 | |||
| 276 | 33 | $bom = ''; |
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| 277 | 33 | if (!$this->is_input_bom_included) { |
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| 278 | 30 | $bom = $this->getInputBOM(); |
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| 279 | } |
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| 280 | |||
| 281 | 33 | $document = $this->getDocument(); |
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| 282 | 33 | $records = $this->stripBOM(new CallbackFilterIterator($document, $normalized), $bom); |
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| 283 | 33 | if (null !== $this->header_offset) { |
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| 284 | $records = new CallbackFilterIterator($records, function (array $record, int $offset): bool { |
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| 285 | 18 | return $offset !== $this->header_offset; |
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| 286 | 18 | }); |
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| 287 | } |
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| 288 | |||
| 289 | 33 | if ($this->is_empty_records_included) { |
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| 290 | $normalized_empty_records = static function (array $record): array { |
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| 291 | 12 | if ([null] === $record) { |
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| 292 | 12 | return []; |
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| 293 | } |
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| 294 | |||
| 295 | 12 | return $record; |
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| 296 | 12 | }; |
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| 297 | |||
| 298 | 12 | return $this->combineHeader(new MapIterator($records, $normalized_empty_records), $header); |
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| 299 | } |
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| 300 | |||
| 301 | 33 | return $this->combineHeader($records, $header); |
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| 302 | } |
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| 303 | |||
| 304 | /** |
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| 305 | * Returns the header to be used for iteration. |
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| 306 | * |
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| 307 | * @param string[] $header |
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| 308 | * |
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| 309 | * @throws Exception If the header contains non unique column name |
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| 310 | * |
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| 311 | * @return string[] |
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| 312 | */ |
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| 313 | 30 | protected function computeHeader(array $header) |
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| 325 | |||
| 326 | /** |
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| 327 | * Combine the CSV header to each record if present. |
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| 328 | * |
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| 329 | * @param string[] $header |
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| 330 | */ |
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| 331 | 36 | protected function combineHeader(Iterator $iterator, array $header): Iterator |
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| 332 | { |
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| 333 | 36 | if ([] === $header) { |
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| 334 | 27 | return $iterator; |
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| 335 | } |
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| 336 | |||
| 337 | 12 | $field_count = count($header); |
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| 351 | |||
| 352 | /** |
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| 353 | * Strip the BOM sequence from the returned records if necessary. |
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| 354 | */ |
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| 355 | 30 | protected function stripBOM(Iterator $iterator, string $bom): Iterator |
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| 372 | |||
| 373 | /** |
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| 374 | * Selects the record to be used as the CSV header. |
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| 375 | * |
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| 376 | * Because the header is represented as an array, to be valid |
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| 377 | * a header MUST contain only unique string value. |
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| 378 | * |
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| 379 | * @param int|null $offset the header record offset |
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| 380 | * |
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| 381 | * @throws Exception if the offset is a negative integer |
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| 382 | * |
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| 383 | * @return static |
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| 384 | */ |
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| 385 | 27 | public function setHeaderOffset(?int $offset): self |
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| 400 | |||
| 401 | /** |
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| 402 | * Enable skipping empty records. |
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| 403 | */ |
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| 404 | 12 | public function skipEmptyRecords(): self |
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| 413 | |||
| 414 | /** |
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| 415 | * Disable skipping empty records. |
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| 416 | */ |
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| 417 | 12 | public function includeEmptyRecords(): self |
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| 426 | |||
| 427 | /** |
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| 428 | * Tells whether empty records are skipped by the instance. |
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| 429 | */ |
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| 430 | 12 | public function isEmptyRecordsIncluded(): bool |
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| 434 | } |
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| 435 |