Complex classes like Page 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 Page, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 21 | class Page extends Item  | 
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| 22 | { | 
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| 23 | use VariableTrait;  | 
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| 24 | |||
| 25 | const SLUGIFY_PATTERN = '/(^\/|[^a-z0-9\/]|-)+/';  | 
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| 26 | // https://regex101.com/r/tJWUrd/1  | 
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| 27 |     const PREFIX_PATTERN = '^(.*?)(([0-9]{4})-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])|[0-9]+)(-|_|\.)(.*)$'; | 
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| 28 | |||
| 29 | /**  | 
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| 30 | * @var SplFileInfo  | 
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| 31 | */  | 
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| 32 | protected $file;  | 
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| 33 | /**  | 
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| 34 | * @var string  | 
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| 35 | */  | 
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| 36 | protected $fileExtension;  | 
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| 37 | /**  | 
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| 38 | * @var string  | 
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| 39 | */  | 
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| 40 | protected $filePath;  | 
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| 41 | /**  | 
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| 42 | * @var string  | 
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| 43 | */  | 
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| 44 | protected $fileName;  | 
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| 45 | /**  | 
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| 46 | * @var string  | 
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| 47 | */  | 
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| 48 | protected $fileId;  | 
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| 49 | /**  | 
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| 50 | * @var bool  | 
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| 51 | */  | 
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| 52 | protected $virtual = false;  | 
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| 53 | /**  | 
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| 54 | * @var string  | 
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| 55 | */  | 
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| 56 | protected $nodeType;  | 
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| 57 | /**  | 
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| 58 | * @var string  | 
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| 59 | */  | 
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| 60 | protected $id;  | 
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| 61 | /**  | 
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| 62 | * @var string  | 
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| 63 | */  | 
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| 64 | protected $pathname;  | 
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| 65 | /**  | 
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| 66 | * @var string  | 
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| 67 | */  | 
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| 68 | protected $path;  | 
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| 69 | /**  | 
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| 70 | * @var string  | 
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| 71 | */  | 
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| 72 | protected $name;  | 
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| 73 | /**  | 
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| 74 | * @var string  | 
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| 75 | */  | 
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| 76 | protected $frontmatter;  | 
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| 77 | /**  | 
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| 78 | * @var string  | 
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| 79 | */  | 
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| 80 | protected $body;  | 
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| 81 | /**  | 
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| 82 | * @var string  | 
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| 83 | */  | 
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| 84 | protected $html;  | 
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| 85 | |||
| 86 | /**  | 
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| 87 | * Constructor.  | 
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| 88 | *  | 
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| 89 | * @param SplFileInfo|null $file  | 
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| 90 | */  | 
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| 91 | public function __construct(SplFileInfo $file = null)  | 
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| 92 |     { | 
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| 93 | $this->file = $file;  | 
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| 94 | |||
| 95 |         if ($this->file instanceof SplFileInfo) { | 
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| 96 | // file extension: "md"  | 
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| 97 | $this->fileExtension = pathinfo($this->file, PATHINFO_EXTENSION);  | 
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| 98 | // file path: "Blog"  | 
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| 99 | $this->filePath = str_replace(DIRECTORY_SEPARATOR, '/', $this->file->getRelativePath());  | 
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| 100 | // file name: "Post 1"  | 
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| 101 | $this->fileName = basename($this->file->getBasename(), '.'.$this->fileExtension);  | 
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| 102 | // file id: "Blog/Post 1"  | 
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| 103 | $this->fileId = ($this->filePath ? $this->filePath.'/' : '')  | 
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| 104 | .($this->filePath && $this->fileName == 'index' ? '' : $this->fileName);  | 
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| 105 | /*  | 
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| 106 | * variables default values  | 
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| 107 | */  | 
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| 108 | // id - ie: "blog/post-1"  | 
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| 109 | $this->id = $this->urlize(self::subPrefix($this->fileId));  | 
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| 110 | // pathname - ie: "blog/post-1"  | 
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| 111 | $this->pathname = $this->urlize(self::subPrefix($this->fileId));  | 
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| 112 | // path - ie: "blog"  | 
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| 113 | $this->path = $this->urlize($this->filePath);  | 
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| 114 | // name - ie: "post-1"  | 
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| 115 | $this->name = $this->urlize(self::subPrefix($this->fileName));  | 
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| 116 | /*  | 
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| 117 | * front matter default values  | 
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| 118 | */  | 
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| 119 | // title - ie: "Post 1"  | 
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| 120 | $this->setTitle(self::subPrefix($this->fileName));  | 
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| 121 | // section - ie: "blog"  | 
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| 122 |             $this->setSection(explode('/', $this->path)[0]); | 
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| 123 | // date from file meta  | 
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| 124 | $this->setDate(filemtime($this->file->getPathname()));  | 
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| 125 | // file as a prefix?  | 
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| 126 |             if (false !== self::getPrefix($this->fileId)) { | 
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| 127 | // prefix is a valid date?  | 
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| 128 |                 $isValidDate = function ($date, $format = 'Y-m-d') { | 
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| 129 | $d = \DateTime::createFromFormat($format, $date);  | 
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| 130 | |||
| 131 | return $d && $d->format($format) === $date;  | 
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| 132 | };  | 
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| 133 |                 if ($isValidDate(self::getPrefix($this->fileId))) { | 
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| 134 | $this->setDate(self::getPrefix($this->fileId));  | 
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| 
                                                                                                    
                        
                         | 
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| 135 |                 } else { | 
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| 136 | // prefix is an integer  | 
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| 137 | $this->setWeight(self::getPrefix($this->fileId));  | 
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| 138 | }  | 
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| 139 | }  | 
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| 140 | // permalink  | 
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| 141 | $this->setPermalink($this->pathname);  | 
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| 142 | |||
| 143 | parent::__construct($this->id);  | 
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| 144 |         } else { | 
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| 145 | $this->virtual = true;  | 
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| 146 | |||
| 147 | parent::__construct();  | 
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| 148 | }  | 
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| 149 |         $this->setVariable('virtual', $this->virtual); | 
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| 150 |         $this->setVariable('published', true); | 
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| 151 |         $this->setVariable('content_template', 'page.content.twig'); | 
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| 152 | }  | 
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| 153 | |||
| 154 | /**  | 
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| 155 | * Return matches array if prefix exist or false.  | 
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| 156 | *  | 
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| 157 | * @param string $string  | 
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| 158 | *  | 
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| 159 | * @return string[]|false  | 
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| 160 | */  | 
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| 161 | public static function hasPrefix(string $string)  | 
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| 162 |     { | 
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| 163 |         if (preg_match('/'.self::PREFIX_PATTERN.'/', $string, $matches)) { | 
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| 164 | return $matches;  | 
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| 165 |         } else { | 
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| 166 | return false;  | 
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| 167 | }  | 
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| 168 | }  | 
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| 169 | |||
| 170 | /**  | 
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| 171 | * Return prefix if prefix or false.  | 
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| 172 | *  | 
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| 173 | * @param string $string  | 
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| 174 | *  | 
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| 175 | * @return string[]|false  | 
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| 176 | */  | 
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| 177 | public static function getPrefix(string $string)  | 
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| 178 |     { | 
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| 179 |         if (false !== ($matches = self::hasPrefix($string))) { | 
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| 180 | return $matches[2];  | 
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| 181 | }  | 
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| 182 | |||
| 183 | return false;  | 
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| 184 | }  | 
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| 185 | |||
| 186 | /**  | 
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| 187 | * Return string without prefix (if exist).  | 
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| 188 | *  | 
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| 189 | * @param string $string  | 
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| 190 | *  | 
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| 191 | * @return string  | 
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| 192 | */  | 
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| 193 | public static function subPrefix(string $string): string  | 
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| 194 |     { | 
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| 195 |         if (false !== ($matches = self::hasPrefix($string))) { | 
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| 196 | return $matches[1].$matches[7];  | 
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| 197 | }  | 
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| 198 | |||
| 199 | return $string;  | 
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| 200 | }  | 
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| 201 | |||
| 202 | /**  | 
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| 203 | * Format string into URL.  | 
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| 204 | *  | 
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| 205 | * @param string $string  | 
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| 206 | *  | 
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| 207 | * @return string  | 
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| 208 | */  | 
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| 209 | public static function urlize(string $string): string  | 
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| 210 |     { | 
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| 211 | return Slugify::create([  | 
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| 212 | 'regexp' => self::SLUGIFY_PATTERN,  | 
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| 213 | ])->slugify($string);  | 
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| 214 | }  | 
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| 215 | |||
| 216 | /**  | 
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| 217 | * Is current page is virtual?  | 
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| 218 | *  | 
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| 219 | * @return bool  | 
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| 220 | */  | 
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| 221 | public function isVirtual(): bool  | 
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| 222 |     { | 
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| 223 | return $this->virtual;  | 
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| 224 | }  | 
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| 225 | |||
| 226 | /**  | 
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| 227 | * Set node type.  | 
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| 228 | *  | 
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| 229 | * @param string $nodeType  | 
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| 230 | *  | 
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| 231 | * @return self  | 
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| 232 | */  | 
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| 233 | public function setNodeType(string $nodeType): self  | 
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| 234 |     { | 
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| 235 | $this->nodeType = new NodeType($nodeType);  | 
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| 236 | |||
| 237 | return $this;  | 
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| 238 | }  | 
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| 239 | |||
| 240 | /**  | 
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| 241 | * Get node type.  | 
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| 242 | *  | 
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| 243 | * @return string|null  | 
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| 244 | */  | 
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| 245 | public function getNodeType(): ?string  | 
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| 246 |     { | 
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| 247 | return $this->nodeType;  | 
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| 248 | }  | 
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| 249 | |||
| 250 | /**  | 
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| 251 | * Parse file content.  | 
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| 252 | *  | 
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| 253 | * @return self  | 
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| 254 | */  | 
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| 255 | public function parse(): self  | 
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| 256 |     { | 
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| 257 | $parser = new Parser($this->file);  | 
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| 258 | $parsed = $parser->parse();  | 
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| 259 | $this->frontmatter = $parsed->getFrontmatter();  | 
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| 260 | $this->body = $parsed->getBody();  | 
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| 261 | |||
| 262 | return $this;  | 
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| 263 | }  | 
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| 264 | |||
| 265 | /**  | 
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| 266 | * Set name.  | 
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| 267 | *  | 
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| 268 | * @param string $name  | 
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| 269 | *  | 
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| 270 | * @return self  | 
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| 271 | */  | 
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| 272 | public function setName(string $name): self  | 
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| 273 |     { | 
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| 274 | $this->name = $name;  | 
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| 275 | |||
| 276 | return $this;  | 
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| 277 | }  | 
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| 278 | |||
| 279 | /**  | 
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| 280 | * Get name.  | 
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| 281 | *  | 
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| 282 | * @return string|null  | 
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| 283 | */  | 
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| 284 | public function getName(): ?string  | 
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| 285 |     { | 
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| 286 | return $this->name;  | 
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| 287 | }  | 
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| 288 | |||
| 289 | /**  | 
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| 290 | * Set path.  | 
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| 291 | *  | 
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| 292 | * @param $path  | 
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| 293 | *  | 
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| 294 | * @return self  | 
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| 295 | */  | 
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| 296 | public function setPath(string $path): self  | 
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| 297 |     { | 
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| 298 | $this->path = $path;  | 
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| 299 | |||
| 300 | return $this;  | 
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| 301 | }  | 
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| 302 | |||
| 303 | /**  | 
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| 304 | * Get path.  | 
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| 305 | *  | 
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| 306 | * @return string  | 
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| 307 | */  | 
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| 308 | public function getPath(): string  | 
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| 309 |     { | 
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| 310 | return $this->path;  | 
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| 311 | }  | 
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| 312 | |||
| 313 | /**  | 
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| 314 | * Set path name.  | 
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| 315 | *  | 
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| 316 | * @param string $pathname  | 
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| 317 | *  | 
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| 318 | * @return self  | 
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| 319 | */  | 
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| 320 | public function setPathname(string $pathname): self  | 
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| 321 |     { | 
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| 322 | $this->pathname = $pathname;  | 
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| 323 | |||
| 324 | return $this;  | 
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| 325 | }  | 
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| 326 | |||
| 327 | /**  | 
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| 328 | * Get path name.  | 
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| 329 | *  | 
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| 330 | * @return string  | 
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| 331 | */  | 
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| 332 | public function getPathname(): string  | 
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| 333 |     { | 
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| 334 | return $this->pathname;  | 
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| 335 | }  | 
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| 336 | |||
| 337 | /**  | 
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| 338 | * Set section.  | 
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| 339 | *  | 
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| 340 | * @param string $section  | 
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| 341 | *  | 
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| 342 | * @return self  | 
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| 343 | */  | 
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| 344 | public function setSection(string $section): self  | 
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| 345 |     { | 
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| 346 |         $this->setVariable('section', $section); | 
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| 347 | |||
| 348 | return $this;  | 
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| 349 | }  | 
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| 350 | |||
| 351 | /**  | 
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| 352 | * Get section.  | 
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| 353 | *  | 
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| 354 | * @return string|false  | 
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| 355 | */  | 
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| 356 | public function getSection(): ?string  | 
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| 357 |     { | 
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| 358 |         if (empty($this->getVariable('section')) && !empty($this->path)) { | 
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| 359 |             $this->setSection(explode('/', $this->path)[0]); | 
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| 360 | }  | 
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| 361 | |||
| 362 |         return $this->getVariable('section'); | 
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| 363 | }  | 
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| 364 | |||
| 365 | /**  | 
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| 366 | * Set title.  | 
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| 367 | *  | 
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| 368 | * @param string $title  | 
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| 369 | *  | 
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| 370 | * @return self  | 
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| 371 | */  | 
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| 372 | public function setTitle(string $title): self  | 
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| 373 |     { | 
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| 374 |         $this->setVariable('title', $title); | 
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| 375 | |||
| 376 | return $this;  | 
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| 377 | }  | 
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| 378 | |||
| 379 | /**  | 
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| 380 | * Get title.  | 
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| 381 | *  | 
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| 382 | * @return string|false  | 
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| 383 | */  | 
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| 384 | public function getTitle(): ?string  | 
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| 385 |     { | 
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| 386 |         return $this->getVariable('title'); | 
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| 387 | }  | 
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| 388 | |||
| 389 | /**  | 
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| 390 | * Set date.  | 
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| 391 | *  | 
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| 392 | * @param string|\DateTime $date  | 
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| 393 | *  | 
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| 394 | * @return self  | 
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| 395 | */  | 
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| 396 | public function setDate($date): self  | 
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| 397 |     { | 
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| 398 |         $this->setVariable('date', $date); | 
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| 399 | |||
| 400 | return $this;  | 
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| 401 | }  | 
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| 402 | |||
| 403 | /**  | 
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| 404 | * Get Date.  | 
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| 405 | *  | 
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| 406 | * @return \DateTime|false  | 
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| 407 | */  | 
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| 408 | public function getDate(): ?\DateTime  | 
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| 409 |     { | 
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| 410 |         return $this->getVariable('date'); | 
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| 411 | }  | 
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| 412 | |||
| 413 | /**  | 
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| 414 | * Set weight.  | 
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| 415 | *  | 
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| 416 | * @param int $weight  | 
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| 417 | *  | 
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| 418 | * @return self  | 
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| 419 | */  | 
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| 420 | public function setWeight(int $weight): self  | 
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| 421 |     { | 
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| 422 |         $this->setVariable('weight', $weight); | 
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| 423 | |||
| 424 | return $this;  | 
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| 425 | }  | 
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| 426 | |||
| 427 | /**  | 
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| 428 | * Get weight.  | 
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| 429 | *  | 
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| 430 | * @return int|null  | 
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| 431 | */  | 
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| 432 | public function getWeight(): ?int  | 
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| 433 |     { | 
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| 434 |         return $this->getVariable('weight'); | 
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| 435 | }  | 
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| 436 | |||
| 437 | /**  | 
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| 438 | * Set permalink.  | 
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| 439 | *  | 
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| 440 | * @param string $permalink  | 
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| 441 | *  | 
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| 442 | * @return self  | 
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| 443 | */  | 
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| 444 | public function setPermalink(string $permalink): self  | 
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| 445 |     { | 
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| 446 | // https://regex101.com/r/45oTKm/1  | 
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| 447 |         $permalink = preg_replace('/index$/i', '', $permalink); | 
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| 448 | |||
| 449 |         $this->setVariable('permalink', $permalink); | 
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| 450 | |||
| 451 | return $this;  | 
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| 452 | }  | 
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| 453 | |||
| 454 | /**  | 
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| 455 | * Get permalink.  | 
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| 456 | *  | 
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| 457 | * @return string|false  | 
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| 458 | */  | 
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| 459 | public function getPermalink(): ?string  | 
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| 467 | |||
| 468 | /**  | 
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| 469 | * Get frontmatter.  | 
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| 470 | *  | 
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| 471 | * @return string|null  | 
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| 472 | */  | 
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| 473 | public function getFrontmatter(): ?string  | 
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| 477 | |||
| 478 | /**  | 
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| 479 | * Get body.  | 
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| 480 | *  | 
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| 481 | * @return string  | 
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| 482 | */  | 
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| 483 | public function getBody(): string  | 
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| 487 | |||
| 488 | /**  | 
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| 489 | * Set HTML.  | 
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| 490 | *  | 
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| 491 | * @param string $html  | 
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| 492 | *  | 
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| 493 | * @return self  | 
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| 494 | */  | 
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| 495 | public function setHtml(string $html): self  | 
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| 501 | |||
| 502 | /**  | 
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| 503 | * Get HTML alias.  | 
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| 504 | *  | 
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| 505 | * @return string|null  | 
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| 506 | */  | 
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| 507 | public function getContent(): ?string  | 
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| 511 | |||
| 512 | /**  | 
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| 513 | * Set layout.  | 
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| 514 | *  | 
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| 515 | * @param string $layout  | 
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| 516 | *  | 
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| 517 | * @return self  | 
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| 518 | */  | 
            ||
| 519 | public function setLayout(string $layout): self  | 
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| 525 | |||
| 526 | /**  | 
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| 527 | * Get layout.  | 
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| 528 | *  | 
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| 529 | * @return string|false  | 
            ||
| 530 | */  | 
            ||
| 531 | public function getLayout(): ?string  | 
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| 535 | }  | 
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| 536 |