Complex classes like Element 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 Element, and based on these observations, apply Extract Interface, too.
1 | <?php |
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5 | class Element implements ElementInterface |
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6 | { |
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7 | /** |
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8 | * @var \DOMNode |
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9 | */ |
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10 | protected $node; |
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11 | |||
12 | /** |
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13 | * @var ElementInterface|null |
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14 | */ |
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15 | private $nextCached; |
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16 | |||
17 | 90 | /** |
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18 | * @var DOMNode|null |
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19 | 90 | */ |
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20 | 90 | private $previousSiblingCached; |
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21 | |||
22 | public function __construct(\DOMNode $node) |
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23 | { |
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24 | $this->node = $node; |
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25 | 15 | $this->previousSiblingCached = $this->node->previousSibling; |
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26 | } |
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27 | 15 | ||
28 | 15 | /** |
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29 | 15 | * @return bool |
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30 | 15 | */ |
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31 | 15 | public function isBlock() |
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32 | 15 | { |
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33 | 15 | switch ($this->getTagName()) { |
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34 | 15 | case 'blockquote': |
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35 | 15 | case 'body': |
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36 | 15 | case 'div': |
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37 | 15 | case 'h1': |
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38 | 15 | case 'h2': |
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39 | 15 | case 'h3': |
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40 | 12 | case 'h4': |
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41 | 12 | case 'h5': |
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42 | 12 | case 'h6': |
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43 | 3 | case 'hr': |
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44 | case 'html': |
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45 | 12 | case 'li': |
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46 | case 'p': |
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47 | case 'ol': |
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48 | case 'ul': |
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49 | return true; |
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50 | default: |
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51 | return false; |
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52 | 3 | } |
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53 | } |
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54 | 3 | ||
55 | /** |
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56 | * @return bool |
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57 | */ |
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58 | public function isText() |
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59 | { |
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60 | 6 | return $this->getTagName() === '#text'; |
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61 | } |
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62 | 6 | ||
63 | /** |
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64 | * @return bool |
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65 | */ |
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66 | public function isWhitespace() |
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67 | { |
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68 | 90 | return $this->getTagName() === '#text' && trim($this->getValue()) === ''; |
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69 | } |
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70 | 90 | ||
71 | /** |
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72 | * @return string |
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73 | */ |
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74 | public function getTagName() |
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75 | { |
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76 | 78 | return $this->node->nodeName; |
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77 | } |
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78 | 78 | ||
79 | /** |
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80 | * @return string |
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81 | */ |
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82 | public function getValue() |
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83 | { |
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84 | 75 | return $this->node->nodeValue; |
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85 | } |
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86 | 75 | ||
87 | /** |
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88 | * @return ElementInterface|null |
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89 | */ |
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90 | public function getParent() |
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91 | { |
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92 | 90 | return new static($this->node->parentNode) ?: null; |
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93 | } |
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94 | 90 | ||
95 | /** |
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96 | * @return ElementInterface|null |
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97 | */ |
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98 | public function getNextSibling() |
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99 | { |
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100 | 90 | return $this->node->nextSibling !== null ? new static($this->node->nextSibling) : null; |
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101 | } |
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102 | 90 | ||
103 | /** |
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104 | 90 | * @return ElementInterface|null |
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105 | 90 | */ |
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106 | public function getPreviousSibling() |
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107 | { |
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108 | 90 | return $this->previousSiblingCached !== null ? new static($this->previousSiblingCached) : null; |
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109 | } |
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110 | |||
111 | /** |
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112 | * @return bool |
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113 | */ |
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114 | 21 | public function hasChildren() |
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115 | { |
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116 | 21 | return $this->node->hasChildNodes(); |
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117 | 21 | } |
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118 | 21 | ||
119 | 21 | /** |
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120 | * @return ElementInterface[] |
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121 | */ |
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122 | public function getChildren() |
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123 | 21 | { |
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124 | $ret = array(); |
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125 | /** @var \DOMNode $node */ |
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126 | foreach ($this->node->childNodes as $node) { |
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127 | $ret[] = new static($node); |
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128 | } |
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129 | |||
130 | return $ret; |
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131 | } |
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132 | 21 | ||
133 | /** |
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134 | 21 | * @return ElementInterface|null |
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135 | */ |
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136 | public function getNext() |
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137 | { |
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138 | 21 | if ($this->nextCached === null) { |
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139 | 21 | $nextNode = $this->getNextNode($this->node); |
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140 | if ($nextNode !== null) { |
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141 | $this->nextCached = new static($nextNode); |
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142 | 6 | } |
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143 | 6 | } |
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144 | |||
145 | return $this->nextCached; |
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146 | } |
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147 | |||
148 | /** |
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149 | * @param \DomNode $node |
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150 | * @param bool $checkChildren |
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151 | * |
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152 | 90 | * @return \DomNode|null |
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153 | */ |
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154 | 90 | private function getNextNode($node, $checkChildren = true) |
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155 | 3 | { |
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156 | if ($checkChildren && $node->firstChild) { |
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157 | return $node->firstChild; |
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158 | 90 | } |
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159 | 90 | ||
160 | 90 | if ($node->nextSibling) { |
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161 | return $node->nextSibling; |
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162 | } |
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163 | 90 | ||
164 | 24 | if ($node->parentNode) { |
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165 | return $this->getNextNode($node->parentNode, false); |
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166 | } |
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167 | } |
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168 | |||
169 | /** |
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170 | * @param string[]|string $tagNames |
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171 | * |
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172 | * @return bool |
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173 | */ |
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174 | 90 | public function isDescendantOf($tagNames) |
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175 | { |
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176 | 90 | if (!is_array($tagNames)) { |
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177 | 90 | $tagNames = array($tagNames); |
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178 | 90 | } |
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179 | |||
180 | for ($p = $this->node->parentNode; $p !== false; $p = $p->parentNode) { |
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181 | if (is_null($p)) { |
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182 | return false; |
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183 | 81 | } |
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184 | |||
185 | 81 | if (in_array($p->nodeName, $tagNames)) { |
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186 | return true; |
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187 | } |
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188 | } |
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189 | |||
190 | return false; |
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191 | 6 | } |
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192 | |||
193 | 6 | /** |
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194 | * @param string $markdown |
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195 | */ |
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196 | 6 | public function setFinalMarkdown($markdown) |
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197 | 6 | { |
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198 | 6 | $markdown_node = $this->node->ownerDocument->createTextNode($markdown); |
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199 | $this->node->parentNode->replaceChild($markdown_node, $this->node); |
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200 | } |
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201 | |||
202 | /** |
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203 | 6 | * @return string |
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204 | 6 | */ |
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205 | public function getChildrenAsString() |
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206 | { |
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207 | return $this->node->C14N(); |
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208 | 6 | } |
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209 | |||
210 | /** |
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211 | * @return int |
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212 | */ |
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213 | public function getSiblingPosition() |
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232 | |||
233 | /** |
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234 | 30 | * @return int |
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235 | */ |
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236 | 30 | public function getListItemLevel() |
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237 | 30 | { |
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238 | $level = 0; |
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239 | $parent = $this->getParent(); |
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240 | |||
241 | while ($parent !== null && $parent->node->parentNode) { |
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242 | if ($parent->getTagName() === 'li') { |
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243 | $level++; |
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244 | } |
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245 | $parent = $parent->getParent(); |
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246 | } |
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247 | |||
248 | 6 | return $level; |
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250 | 6 | ||
251 | 6 | /** |
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252 | * @param string $name |
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253 | * |
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254 | * @return string |
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255 | */ |
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256 | public function getAttribute($name) |
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264 | |||
265 | /** |
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266 | * @param ElementInterface $element |
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267 | * |
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268 | * @return bool |
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269 | */ |
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270 | public function equals(ElementInterface $element) |
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278 | } |
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279 |
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..