| Total Complexity | 40 |
| Total Lines | 238 |
| Duplicated Lines | 0 % |
| Changes | 1 | ||
| Bugs | 0 | Features | 0 |
Complex classes like Node 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.
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 Node, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 21 | abstract class Node |
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| 22 | { |
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| 23 | /** @psalm-readonly */ |
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| 24 | public Data $data; |
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| 25 | |||
| 26 | /** @psalm-readonly-allow-private-mutation */ |
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| 27 | protected int $depth = 0; |
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| 28 | |||
| 29 | /** @psalm-readonly-allow-private-mutation */ |
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| 30 | protected ?Node $parent = null; |
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| 31 | |||
| 32 | /** @psalm-readonly-allow-private-mutation */ |
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| 33 | protected ?Node $previous = null; |
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| 34 | |||
| 35 | /** @psalm-readonly-allow-private-mutation */ |
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| 36 | protected ?Node $next = null; |
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| 37 | |||
| 38 | /** @psalm-readonly-allow-private-mutation */ |
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| 39 | protected ?Node $firstChild = null; |
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| 40 | |||
| 41 | /** @psalm-readonly-allow-private-mutation */ |
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| 42 | protected ?Node $lastChild = null; |
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| 43 | |||
| 44 | public function __construct() |
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| 45 | { |
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| 46 | $this->data = new Data([ |
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| 47 | 'attributes' => [], |
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| 48 | ]); |
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| 49 | } |
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| 50 | |||
| 51 | public function previous(): ?Node |
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| 52 | { |
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| 53 | return $this->previous; |
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| 54 | } |
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| 55 | |||
| 56 | public function next(): ?Node |
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| 57 | { |
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| 58 | return $this->next; |
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| 59 | } |
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| 60 | |||
| 61 | public function parent(): ?Node |
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| 62 | { |
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| 63 | return $this->parent; |
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| 64 | } |
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| 65 | |||
| 66 | protected function setParent(?Node $node = null): void |
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| 67 | { |
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| 68 | $this->parent = $node; |
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| 69 | $this->depth = $node === null ? 0 : $node->depth + 1; |
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| 70 | } |
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| 71 | |||
| 72 | /** |
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| 73 | * Inserts the $sibling node after $this |
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| 74 | */ |
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| 75 | public function insertAfter(Node $sibling): void |
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| 76 | { |
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| 77 | $sibling->detach(); |
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| 78 | $sibling->next = $this->next; |
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| 79 | |||
| 80 | if ($sibling->next) { |
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| 81 | $sibling->next->previous = $sibling; |
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| 82 | } |
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| 83 | |||
| 84 | $sibling->previous = $this; |
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| 85 | $this->next = $sibling; |
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| 86 | $sibling->setParent($this->parent); |
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| 87 | |||
| 88 | if (! $sibling->next && $sibling->parent) { |
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| 89 | $sibling->parent->lastChild = $sibling; |
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| 90 | } |
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| 91 | } |
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| 92 | |||
| 93 | /** |
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| 94 | * Inserts the $sibling node before $this |
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| 95 | */ |
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| 96 | public function insertBefore(Node $sibling): void |
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| 97 | { |
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| 98 | $sibling->detach(); |
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| 99 | $sibling->previous = $this->previous; |
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| 100 | |||
| 101 | if ($sibling->previous) { |
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| 102 | $sibling->previous->next = $sibling; |
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| 103 | } |
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| 104 | |||
| 105 | $sibling->next = $this; |
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| 106 | $this->previous = $sibling; |
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| 107 | $sibling->setParent($this->parent); |
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| 108 | |||
| 109 | if (! $sibling->previous && $sibling->parent) { |
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| 110 | $sibling->parent->firstChild = $sibling; |
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| 111 | } |
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| 112 | } |
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| 113 | |||
| 114 | public function replaceWith(Node $replacement): void |
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| 115 | { |
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| 116 | $replacement->detach(); |
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| 117 | $this->insertAfter($replacement); |
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| 118 | $this->detach(); |
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| 119 | } |
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| 120 | |||
| 121 | public function detach(): void |
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| 122 | { |
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| 123 | if ($this->previous) { |
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| 124 | $this->previous->next = $this->next; |
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| 125 | } elseif ($this->parent) { |
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| 126 | $this->parent->firstChild = $this->next; |
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| 127 | } |
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| 128 | |||
| 129 | if ($this->next) { |
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| 130 | $this->next->previous = $this->previous; |
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| 131 | } elseif ($this->parent) { |
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| 132 | $this->parent->lastChild = $this->previous; |
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| 133 | } |
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| 134 | |||
| 135 | $this->parent = null; |
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| 136 | $this->next = null; |
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| 137 | $this->previous = null; |
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| 138 | $this->depth = 0; |
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| 139 | } |
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| 140 | |||
| 141 | public function hasChildren(): bool |
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| 142 | { |
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| 143 | return $this->firstChild !== null; |
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| 144 | } |
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| 145 | |||
| 146 | public function firstChild(): ?Node |
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| 149 | } |
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| 150 | |||
| 151 | public function lastChild(): ?Node |
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| 152 | { |
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| 153 | return $this->lastChild; |
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| 154 | } |
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| 155 | |||
| 156 | /** |
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| 157 | * @return Node[] |
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| 158 | */ |
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| 159 | public function children(): iterable |
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| 160 | { |
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| 161 | $children = []; |
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| 162 | for ($current = $this->firstChild; $current !== null; $current = $current->next) { |
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| 163 | $children[] = $current; |
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| 164 | } |
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| 165 | |||
| 166 | return $children; |
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| 167 | } |
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| 168 | |||
| 169 | public function appendChild(Node $child): void |
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| 170 | { |
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| 171 | if ($this->lastChild) { |
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| 172 | $this->lastChild->insertAfter($child); |
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| 173 | } else { |
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| 174 | $child->detach(); |
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| 175 | $child->setParent($this); |
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| 176 | $this->lastChild = $this->firstChild = $child; |
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| 177 | } |
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| 178 | } |
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| 179 | |||
| 180 | /** |
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| 181 | * Adds $child as the very first child of $this |
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| 182 | */ |
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| 183 | public function prependChild(Node $child): void |
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| 184 | { |
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| 185 | if ($this->firstChild) { |
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| 186 | $this->firstChild->insertBefore($child); |
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| 187 | } else { |
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| 188 | $child->detach(); |
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| 189 | $child->setParent($this); |
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| 190 | $this->lastChild = $this->firstChild = $child; |
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| 191 | } |
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| 192 | } |
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| 193 | |||
| 194 | /** |
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| 195 | * Detaches all child nodes of given node |
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| 196 | */ |
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| 197 | public function detachChildren(): void |
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| 198 | { |
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| 199 | foreach ($this->children() as $children) { |
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| 200 | $children->setParent(null); |
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| 201 | } |
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| 202 | |||
| 203 | $this->firstChild = $this->lastChild = null; |
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| 204 | } |
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| 205 | |||
| 206 | /** |
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| 207 | * Replace all children of given node with collection of another |
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| 208 | * |
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| 209 | * @param iterable<Node> $children |
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| 210 | */ |
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| 211 | public function replaceChildren(iterable $children): void |
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| 212 | { |
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| 213 | $this->detachChildren(); |
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| 214 | foreach ($children as $item) { |
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| 215 | $this->appendChild($item); |
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| 216 | } |
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| 217 | } |
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| 218 | |||
| 219 | public function getDepth(): int |
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| 220 | { |
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| 221 | return $this->depth; |
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| 222 | } |
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| 223 | |||
| 224 | public function walker(): NodeWalker |
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| 225 | { |
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| 226 | return new NodeWalker($this); |
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| 227 | } |
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| 228 | |||
| 229 | public function iterator(int $flags = 0): NodeIterator |
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| 232 | } |
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| 233 | |||
| 234 | /** |
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| 235 | * Clone the current node and its children |
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| 236 | * |
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| 237 | * WARNING: This is a recursive function and should not be called on deeply-nested node trees! |
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| 238 | */ |
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| 239 | public function __clone() |
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| 240 | { |
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| 241 | // Cloned nodes are detached from their parents, siblings, and children |
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| 242 | $this->parent = null; |
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| 243 | $this->previous = null; |
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| 244 | $this->next = null; |
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| 245 | // But save a copy of the children since we'll need that in a moment |
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| 246 | $children = $this->children(); |
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| 247 | $this->detachChildren(); |
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| 248 | |||
| 249 | // The original children get cloned and re-added |
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| 250 | foreach ($children as $child) { |
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| 251 | $this->appendChild(clone $child); |
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| 252 | } |
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| 253 | } |
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| 254 | |||
| 255 | public static function assertInstanceOf(Node $node): void |
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| 259 | } |
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| 260 | } |
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| 261 | } |
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| 262 |