Complex classes like Frontmatter 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 Frontmatter, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
||
| 10 | class Frontmatter implements FilterInterface |
||
| 11 | { |
||
| 12 | /** |
||
| 13 | * @var array $config with options on how to parse text. |
||
| 14 | */ |
||
| 15 | protected $config; |
||
| 16 | |||
| 17 | |||
| 18 | |||
| 19 | /** |
||
| 20 | * @var array $lines text split into lines. |
||
| 21 | */ |
||
| 22 | protected $lines; |
||
| 23 | |||
| 24 | |||
| 25 | |||
| 26 | /** |
||
| 27 | * @var array $lineNumber current line number being parsed. |
||
| 28 | */ |
||
| 29 | protected $lineNumber; |
||
| 30 | |||
| 31 | |||
| 32 | |||
| 33 | /** |
||
| 34 | * @var integer $linesRemoved keep track on how many lines is removed. |
||
| 35 | */ |
||
| 36 | protected $linesRemoved; |
||
| 37 | |||
| 38 | |||
| 39 | |||
| 40 | /** |
||
| 41 | * @var array $frontmatter parsed as frontmatter, accumulated when parsing |
||
| 42 | * the text. |
||
| 43 | */ |
||
| 44 | protected $frontmatter; |
||
| 45 | |||
| 46 | |||
| 47 | |||
| 48 | /** |
||
| 49 | * @var array $blockTypes with details on block to detect. |
||
| 50 | */ |
||
| 51 | protected $blockTypes = [ |
||
| 52 | "#" => ["Include"], |
||
| 53 | "-" => ["YamlFrontmatter"], |
||
| 54 | "{" => ["JsonFrontmatter"], |
||
| 55 | ]; |
||
| 56 | |||
| 57 | |||
| 58 | |||
| 59 | /** |
||
| 60 | * Parse the text through the filter and do what the filter does, |
||
| 61 | * return the resulting text and with some optional additional details, |
||
| 62 | * all wrapped in an key-value array. |
||
| 63 | * |
||
| 64 | * @param string $text to parse. |
||
| 65 | * @param array $frontmatter optional to use while parsing. |
||
| 66 | * @param array $options custom options to use while parsing. |
||
| 67 | * |
||
| 68 | * @return array with the resulting text and frontmatter. |
||
| 69 | */ |
||
| 70 | 36 | public function parse($text, array $frontmatter, array $options = []) |
|
| 97 | |||
| 98 | |||
| 99 | |||
| 100 | // /** |
||
| 101 | // * Debugging and visualising parsing by printing information on current row. |
||
| 102 | // * |
||
| 103 | // * @param string $msg additional message to print. |
||
| 104 | // */ |
||
| 105 | // private function log($msg) |
||
| 106 | // { |
||
| 107 | // $lineNumber = $this->lineNumber + $this->linesRemoved; |
||
| 108 | // $line = $this->currentLine(); |
||
| 109 | // |
||
| 110 | // echo <<<EOD |
||
| 111 | // |
||
| 112 | // ***{$lineNumber}: $msg |
||
| 113 | // {$line} |
||
| 114 | // *** |
||
| 115 | // |
||
| 116 | // EOD; |
||
| 117 | // } |
||
| 118 | |||
| 119 | |||
| 120 | |||
| 121 | /** |
||
| 122 | * Parse each line and look into it to see whats need to be done. |
||
| 123 | * |
||
| 124 | * @return array with the resulting text and optional additional items. |
||
| 125 | */ |
||
| 126 | 34 | public function parseLines() |
|
| 163 | |||
| 164 | |||
| 165 | |||
| 166 | /** |
||
| 167 | * Get current line to parse. |
||
| 168 | * |
||
| 169 | * @return string|boolean containing text for current row or false when |
||
| 170 | * reached EOF. |
||
| 171 | */ |
||
| 172 | 34 | public function currentLine() |
|
| 178 | |||
| 179 | |||
| 180 | |||
| 181 | /** |
||
| 182 | * Get next line to parse and keep track on current line being parsed. |
||
| 183 | * |
||
| 184 | * @return string|boolean containing text for next row or false when |
||
| 185 | * reached EOF. |
||
| 186 | */ |
||
| 187 | 34 | public function nextLine() |
|
| 192 | |||
| 193 | |||
| 194 | |||
| 195 | /** |
||
| 196 | * Detect and include external file, add it to lines array and parse it. |
||
| 197 | * |
||
| 198 | * @param string $line to begin parsing. |
||
| 199 | * |
||
| 200 | * @return boolean|void true when block is found and parsed, else void. |
||
| 201 | */ |
||
| 202 | 7 | protected function blockInclude($line) |
|
| 227 | |||
| 228 | |||
| 229 | |||
| 230 | /** |
||
| 231 | * Detect and extract block with YAML frontmatter from the lines array. |
||
| 232 | * |
||
| 233 | * @param string $line to begin parsing. |
||
| 234 | * |
||
| 235 | * @return boolean|void true when block is found and parsed, else void. |
||
| 236 | * |
||
| 237 | * @SuppressWarnings(PHPMD.CyclomaticComplexity) |
||
| 238 | */ |
||
| 239 | 20 | protected function blockYamlFrontmatter($line) |
|
| 281 | |||
| 282 | |||
| 283 | |||
| 284 | /** |
||
| 285 | * Extract YAML frontmatter from text and merge into existing frontmatter. |
||
| 286 | * |
||
| 287 | * @param array $lines the YAML to parsed. |
||
| 288 | * |
||
| 289 | * @return void. |
||
| 290 | */ |
||
| 291 | 18 | protected function addYamlFrontmatter($lines) |
|
| 302 | |||
| 303 | |||
| 304 | |||
| 305 | /** |
||
| 306 | * Parse YAML front matter from text, use one of several available |
||
| 307 | * implementations of a YAML parser. |
||
| 308 | * |
||
| 309 | * @param string $text the YAML to parsed. |
||
| 310 | * |
||
| 311 | * @return void. |
||
| 312 | * |
||
| 313 | * @throws Exception when parsing frontmatter fails of is not installed. |
||
| 314 | */ |
||
| 315 | 18 | protected function parseYaml($text) |
|
| 347 | |||
| 348 | |||
| 349 | |||
| 350 | /** |
||
| 351 | * Detect and extract block with JSON frontmatter from the lines array. |
||
| 352 | * |
||
| 353 | * @param string $line to begin parsing. |
||
| 354 | * |
||
| 355 | * @return boolean|void true when block is found and parsed, else void. |
||
| 356 | * |
||
| 357 | * @SuppressWarnings(PHPMD.CyclomaticComplexity) |
||
| 358 | */ |
||
| 359 | 13 | protected function blockJsonFrontmatter($line) |
|
| 399 | |||
| 400 | |||
| 401 | |||
| 402 | /** |
||
| 403 | * Extract JSON frontmatter from text and merge into existing frontmatter. |
||
| 404 | * |
||
| 405 | * @param array $lines the JSON to parsed. |
||
| 406 | * |
||
| 407 | * @return void. |
||
| 408 | */ |
||
| 409 | 11 | protected function addJsonFrontmatter($lines) |
|
| 428 | } |
||
| 429 |
Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property.
Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property..