Complex classes like Parser 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 Parser, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 45 | class Parser |
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| 46 | { |
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| 47 | /** @var SourceHandler */ |
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| 48 | protected $sourceHandler; |
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| 49 | |||
| 50 | /** @var int */ |
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| 51 | protected $lineNumber; |
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| 52 | |||
| 53 | /** @var string */ |
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| 54 | protected $property; |
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| 55 | |||
| 56 | /** |
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| 57 | * Reads and parses a string |
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| 58 | * |
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| 59 | * @param string $string po content |
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| 60 | * |
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| 61 | * @throws \Exception. |
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| 62 | * @return Parser |
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| 63 | */ |
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| 64 | public static function parseString($string) |
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| 71 | |||
| 72 | /** |
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| 73 | * Reads and parses a file |
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| 74 | * |
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| 75 | * @param string $filePath |
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| 76 | * |
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| 77 | * @throws \Exception. |
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| 78 | * @return Catalog |
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| 79 | */ |
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| 80 | public static function parseFile($filePath) |
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| 86 | |||
| 87 | public function __construct(SourceHandler $sourceHandler) |
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| 91 | |||
| 92 | /** |
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| 93 | * Reads and parses strings of a .po file. |
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| 94 | * |
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| 95 | * @param SourceHandler . Optional |
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| 96 | * |
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| 97 | * @throws \Exception, \InvalidArgumentException, ParseException |
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| 98 | * @return Catalog |
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| 99 | */ |
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| 100 | public function parse() |
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| 101 | { |
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| 102 | $catalog = new Catalog(); |
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| 103 | $this->lineNumber = 0; |
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| 104 | $entry = array(); |
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| 105 | $this->mode = null; // current mode |
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| 106 | $this->property = null; // current property |
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| 107 | |||
| 108 | // Flags |
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| 109 | $headersFound = false; |
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| 110 | |||
| 111 | while (!$this->sourceHandler->ended()) { |
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| 112 | |||
| 113 | $line = trim($this->sourceHandler->getNextLine()); |
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| 114 | |||
| 115 | if ($this->shouldIgnoreLine($line, $entry)) { |
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| 116 | $this->lineNumber++; |
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| 117 | continue; |
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| 118 | } |
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| 119 | |||
| 120 | if ($this->shouldCloseEntry($line, $entry)) { |
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| 121 | if (!$headersFound && $this->isHeader($entry)) { |
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| 122 | $headersFound = true; |
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| 123 | $catalog->addHeaders( |
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| 124 | $this->parseHeaders($entry['msgstr']) |
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| 125 | ); |
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| 126 | } else { |
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| 127 | $catalog->addEntry(EntryFactory::createFromArray($entry)); |
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| 128 | } |
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| 129 | |||
| 130 | $entry = array(); |
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| 131 | $this->property = null; |
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| 132 | |||
| 133 | if (empty($line)) { |
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| 134 | $this->lineNumber++; |
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| 135 | continue; |
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| 136 | } |
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| 137 | } |
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| 138 | |||
| 139 | $entry = $this->parseLine($line, $entry); |
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| 140 | |||
| 141 | $this->lineNumber++; |
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| 142 | continue; |
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| 143 | } |
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| 144 | $this->sourceHandler->close(); |
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| 145 | |||
| 146 | // add final entry |
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| 147 | if (count($entry)) { |
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| 148 | $catalog->addEntry(EntryFactory::createFromArray($entry)); |
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| 149 | } |
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| 150 | |||
| 151 | return $catalog; |
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| 152 | } |
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| 153 | |||
| 154 | /** |
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| 155 | * @param string $line |
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| 156 | * @param array $entry |
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| 157 | * |
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| 158 | * @return array |
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| 159 | * @throws ParseException |
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| 160 | */ |
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| 161 | protected function parseLine($line, $entry) |
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| 162 | { |
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| 163 | $firstChar = strlen($line) > 0 ? $line[0] : ''; |
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| 164 | |||
| 165 | switch ($firstChar) { |
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| 166 | case '#': |
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| 167 | $entry = $this->parseComment($line, $entry); |
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| 168 | break; |
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| 169 | |||
| 170 | case 'm': |
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| 171 | $entry = $this->parseProperty($line, $entry); |
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| 172 | break; |
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| 173 | |||
| 174 | case '"': |
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| 175 | $entry = $this->parseMultiline($line, $entry); |
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| 176 | break; |
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| 177 | } |
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| 178 | |||
| 179 | return $entry; |
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| 180 | } |
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| 181 | |||
| 182 | /** |
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| 183 | * @param string $line |
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| 184 | * @param array $entry |
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| 185 | * |
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| 186 | * @return array |
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| 187 | * @throws ParseException |
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| 188 | */ |
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| 189 | protected function parseProperty($line, array $entry) |
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| 190 | { |
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| 191 | list($key, $value) = $this->getProperty($line); |
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| 192 | |||
| 193 | if (!isset($entry[$key])) { |
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| 194 | $entry[$key] = ''; |
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| 195 | } |
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| 196 | |||
| 197 | switch (true) { |
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| 198 | case $key === 'msgctxt': |
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| 199 | case $key === 'msgid': |
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| 200 | case $key === 'msgid_plural': |
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| 201 | case $key === 'msgstr': |
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| 202 | $entry[$key] .= $this->unquote($value); |
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| 203 | $this->property = $key; |
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| 204 | break; |
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| 205 | |||
| 206 | case strpos($key, 'msgstr[') !== false: |
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| 207 | $entry[$key] .= $this->unquote($value); |
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| 208 | $this->property = $key; |
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| 209 | break; |
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| 210 | |||
| 211 | default: |
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| 212 | throw new ParseException(sprintf('Could not parse %s at line %d', $key, $this->lineNumber)); |
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| 213 | } |
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| 214 | |||
| 215 | return $entry; |
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| 216 | } |
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| 217 | |||
| 218 | /** |
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| 219 | * @param string $line |
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| 220 | * @param array $entry |
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| 221 | * |
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| 222 | * @return array |
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| 223 | * @throws ParseException |
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| 224 | */ |
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| 225 | protected function parseMultiline($line, $entry) |
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| 226 | { |
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| 227 | switch (true) { |
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| 228 | case $this->property === 'msgctxt': |
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| 229 | case $this->property === 'msgid': |
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| 230 | case $this->property === 'msgid_plural': |
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| 231 | case $this->property === 'msgstr': |
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| 232 | case strpos($this->property, 'msgstr[') !== false: |
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| 233 | $entry[$this->property] .= $this->unquote($line); |
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| 234 | break; |
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| 235 | |||
| 236 | default: |
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| 237 | throw new ParseException( |
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| 238 | sprintf('Error parsing property %s as multiline.', $this->property) |
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| 239 | ); |
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| 240 | } |
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| 241 | |||
| 242 | return $entry; |
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| 243 | } |
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| 244 | |||
| 245 | /** |
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| 246 | * @param string $line |
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| 247 | * @param array $entry |
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| 248 | * |
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| 249 | * @return array |
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| 250 | * @throws ParseException |
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| 251 | */ |
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| 252 | protected function parseComment($line, $entry) |
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| 253 | { |
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| 254 | $comment = trim(substr($line, 0, 2)); |
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| 255 | |||
| 256 | switch ($comment) { |
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| 257 | case '#,': |
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| 258 | $line = trim(substr($line, 2)); |
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| 259 | $entry['flags'] = preg_split('/,\s*/', $line); |
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| 260 | break; |
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| 261 | |||
| 262 | case '#.': |
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| 263 | $entry['ccomment'] = !isset($entry['ccomment']) ? array() : $entry['ccomment']; |
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| 264 | $entry['ccomment'][] = trim(substr($line, 2)); |
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| 265 | break; |
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| 266 | |||
| 267 | |||
| 268 | case '#|': // Previous string |
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| 269 | case '#~': // Old entry |
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| 270 | case '#~|': // Previous string old |
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| 271 | $mode = array( |
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| 272 | '#|' => 'previous', |
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| 273 | '#~' => 'obsolete', |
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| 274 | '#~|' => 'previous-obsolete' |
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| 275 | ); |
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| 276 | |||
| 277 | $line = trim(substr($line, 2)); |
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| 278 | $property = $mode[$comment]; |
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| 279 | if (!isset($entry[$property])) { |
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| 280 | $subEntry = array(); |
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| 281 | } else { |
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| 282 | $subEntry = $entry[$property]; |
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| 283 | } |
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| 284 | |||
| 285 | $subEntry = $this->parseLine($line, $subEntry); |
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| 286 | //$subEntry = $this->parseProperty($line, $subEntry); |
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| 287 | $entry[$property] = $subEntry; |
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| 288 | break; |
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| 289 | |||
| 290 | |||
| 291 | case '#': |
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| 292 | default: |
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| 293 | $entry['tcomment'] = !isset($entry['tcomment']) ? array() : $entry['tcomment']; |
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| 294 | $entry['tcomment'][] = trim(substr($line, 1)); |
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| 295 | break; |
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| 296 | } |
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| 297 | |||
| 298 | return $entry; |
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| 299 | } |
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| 300 | |||
| 301 | /** |
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| 302 | * @param string $msgstr |
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| 303 | * |
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| 304 | * @return array |
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| 305 | */ |
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| 306 | protected function parseHeaders($msgstr) |
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| 307 | { |
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| 308 | $headers = array_filter(explode('\\n', $msgstr)); |
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| 309 | |||
| 310 | return $headers; |
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| 311 | } |
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| 312 | |||
| 313 | /** |
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| 314 | * @param string $line |
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| 315 | * @param array $entry |
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| 316 | * |
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| 317 | * @return bool |
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| 318 | */ |
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| 319 | protected function shouldIgnoreLine($line, array $entry) |
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| 320 | { |
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| 321 | return empty($line) && count($entry) === 0; |
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| 322 | } |
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| 323 | |||
| 324 | /** |
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| 325 | * @param string $line |
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| 326 | * @param array $entry |
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| 327 | * |
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| 328 | * @return bool |
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| 329 | */ |
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| 330 | protected function shouldCloseEntry($line, array $entry) |
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| 331 | { |
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| 332 | $tokens = $this->getProperty($line); |
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| 333 | $property = $tokens[0]; |
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| 334 | |||
| 335 | return ($line === '' || ($property === 'msgid' && isset($entry['msgid']))); |
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| 336 | } |
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| 337 | |||
| 338 | /** |
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| 339 | * @param string $value |
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| 340 | * @return string |
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| 341 | */ |
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| 342 | protected function unquote($value) |
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| 346 | |||
| 347 | /** |
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| 348 | * Checks if entry is a header by |
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| 349 | * |
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| 350 | * @param array $entry |
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| 351 | * |
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| 352 | * @return bool |
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| 353 | */ |
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| 354 | protected function isHeader(array $entry) |
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| 403 | |||
| 404 | /** |
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| 405 | * @param string $line |
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| 406 | * |
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| 407 | * @return array |
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| 408 | */ |
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| 409 | protected function getProperty($line) |
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| 415 | } |
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| 416 |
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: