| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  | declare(strict_types=1); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | namespace TYPO3Fluid\Fluid\Core\Parser\SyntaxTree; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | /* | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  |  * This file belongs to the package "TYPO3 Fluid". | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  |  * See LICENSE.txt that was shipped with this package. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | use TYPO3Fluid\Fluid\Component\AbstractComponent; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  | use TYPO3Fluid\Fluid\Component\ComponentInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  | use TYPO3Fluid\Fluid\Core\Rendering\RenderingContextInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  |  * A node which is used inside boolean arguments | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  | class BooleanNode extends AbstractComponent | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  |     protected $escapeOutput = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |     protected $combiners = ['&&', '||', 'AND', 'OR', 'and', 'or', '&', '|', 'xor', 'XOR']; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |      * @var mixed | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |     protected $value; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |      * @param mixed $input NodeInterface, array (of nodes or expression parts) or a simple type that can be evaluated to boolean | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |     public function __construct($input = null) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |         // First, evaluate everything that is not an ObjectAccessorNode, ArrayNode | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 |  |  |         // or ViewHelper so we get all text, numbers, comparators and | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 |  |  |         // groupers from the text parts of the expression. All other nodes | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |         // we leave intact for later processing | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |         if ($input !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |             $this->value = is_string($input) ? trim($input) : $input; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |     public function addChild(ComponentInterface $component): ComponentInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |         if ($component instanceof TextNode || $component instanceof RootNode && $component->isQuoted()) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |             $this->children[] = $component; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |             parent::addChild($component); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |         return $this; | 
                            
                    |  |  |  | 
                                                                                        
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                | 50 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 51 |  |  |  | 
            
                                                                        
                            
            
                                    
            
            
                | 52 |  |  |     public function flatten(bool $extractNode = false) | 
            
                                                                        
                            
            
                                    
            
            
                | 53 |  |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 54 |  |  |         if ($extractNode && $this->children[0] instanceof TextNode && count($this->children) === 1) { | 
            
                                                                        
                            
            
                                    
            
            
                | 55 |  |  |             return $this->convertToBoolean($this->children[0]->getText()); | 
                            
                    |  |  |  | 
                                                                                        
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                | 56 |  |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 57 |  |  |         return $this; | 
            
                                                                        
                            
            
                                    
            
            
                | 58 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |     public function evaluate(RenderingContextInterface $renderingContext): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |         $combiner = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |         $x = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |         $parts = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |         $negated = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |         foreach ($this->getChildren() as $part) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 |  |  |             $quoted = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |             if ($part instanceof RootNode) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |                 $quoted = $part->isQuoted(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |                 $part = $part->flatten(true); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |             if ($part instanceof TextNode) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |                 $part = $part->getText(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |             if ($part === '!') { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 |  |  |                 $negated = true; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 |  |  |                 continue; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 |  |  |             if ($quoted) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |                 // Quoted expression parts must always be cast to string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |                 $part = (string) $part; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |             } elseif (is_string($part)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |                 // If not quoted the value may be numeric or a hardcoded true/false (not quoted string) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |                 $lowered = strtolower($part); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 |  |  |                 if ($lowered === 'true') { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |                     $part = true; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |                 } elseif ($lowered === 'false') { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 |  |  |                     $part = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 |  |  |                 } elseif (is_numeric($lowered)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 |  |  |                     $part = $part + 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 |  |  |                 } elseif (in_array($part, $this->combiners, true)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 |  |  |                     // And/or encountered. Evaluate parts so far and assign left value. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 |  |  |                     $evaluatedParts = $this->evaluateParts($parts, $renderingContext); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 |  |  |                     $parts = []; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 |  |  |                     if ($combiner !== null && $x !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 |  |  |                         // We must evaluate any parts collected so var | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 |  |  |                         $x = $this->evaluateAndOr($x, $evaluatedParts, $combiner); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |                         $combiner = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 |  |  |                     } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 |  |  |                         $x = $evaluatedParts; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 |  |  |                         $combiner = $part; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |                     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 |  |  |                     if ($negated) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |                         $x = !$x; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |                         $negated = false; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 113 |  |  |                     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |                     if (($x === false && ($part === '&&' || $part === 'AND' || $part === 'and')) || ($x === true && ($part === '||' || $part === 'OR' || $part === 'or'))) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 116 |  |  |                         // If $x is false and condition is AND, or $x is true and condition is OR, then no more | 
            
                                                                                                            
                            
            
                                    
            
            
                | 117 |  |  |                         // evaluation is required and we can return $x now. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 118 |  |  |                         return $x; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 119 |  |  |                     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 120 |  |  |                     continue; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 121 |  |  |                 } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 122 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 123 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 124 |  |  |             $parts[] = $part; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 125 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 126 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 127 |  |  |         if (!empty($parts)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 128 |  |  |             $evaluatedParts = $this->evaluateParts($parts, $renderingContext); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 129 |  |  |             if ($combiner !== null) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 130 |  |  |                 return $this->evaluateAndOr($x, $evaluatedParts, $combiner); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 131 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 132 |  |  |             return $negated ? !$evaluatedParts : $evaluatedParts; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 133 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 134 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 135 |  |  |         $value = $this->value instanceof ComponentInterface ? $this->value->evaluate($renderingContext) : $this->value; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 136 |  |  |         return $this->convertToBoolean($value); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 137 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 138 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 139 |  |  |     protected function evaluateAndOr($x, $y, string $combiner): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 140 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 141 |  |  |         switch ($combiner) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 142 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 143 |  |  |             case '||'; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 144 |  |  |             case 'or': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 145 |  |  |             case 'OR': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 146 |  |  |                 return $x || $y; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 147 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 148 |  |  |             case '&': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 149 |  |  |                 return (bool) ((int) $x & (int) $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 150 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 151 |  |  |             case '|': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 152 |  |  |                 return (bool) ((int) $x | (int) $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 153 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 154 |  |  |             case 'xor': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 155 |  |  |             case 'XOR': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 156 |  |  |                 return (bool) ((int) $x XOR (int) $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 157 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 158 |  |  |             case '&&': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 159 |  |  |             case 'and': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 160 |  |  |             case 'AND': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 161 |  |  |             default: | 
            
                                                                                                            
                            
            
                                    
            
            
                | 162 |  |  |                 return $x && $y; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 163 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 164 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 165 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 166 |  |  |     protected function evaluateParts(array $parts, RenderingContextInterface $renderingContext): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 167 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 168 |  |  |         $numberOfParts = count($parts); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 169 |  |  |         $x = null; | 
                            
                    |  |  |  | 
                                                                                        
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                | 170 |  |  |         if ($numberOfParts === 3) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 171 |  |  |             // Reduce the verdict to one entry in $parts if we've collected enough to evaluate. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 172 |  |  |             // Future loops may re- | 
            
                                                                                                            
                            
            
                                    
            
            
                | 173 |  |  |             $x = $parts[0] instanceof ComponentInterface ? $parts[0]->evaluate($renderingContext) : $parts[0]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 174 |  |  |             $y = $parts[2] instanceof ComponentInterface ? $parts[2]->evaluate($renderingContext) : $parts[2]; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 175 |  |  |             $comparator = (string) ($parts[1] instanceof ComponentInterface ? $parts[1]->evaluate($renderingContext) : $parts[1]); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 176 |  |  |             return $this->evaluateCompare($x, $y, $comparator); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 177 |  |  |         } elseif ($numberOfParts === 1) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 178 |  |  |             return $this->convertToBoolean( | 
            
                                                                                                            
                            
            
                                    
            
            
                | 179 |  |  |                 $parts[0] instanceof ComponentInterface ? $parts[0]->evaluate($renderingContext) : $parts[0] | 
            
                                                                                                            
                            
            
                                    
            
            
                | 180 |  |  |             ); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 181 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 182 |  |  |         return !empty($parts); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 183 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 184 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 185 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 186 |  |  |      * Compare two variables based on a specified comparator | 
            
                                                                                                            
                            
            
                                    
            
            
                | 187 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 188 |  |  |      * @param mixed $x | 
            
                                                                                                            
                            
            
                                    
            
            
                | 189 |  |  |      * @param mixed $y | 
            
                                                                                                            
                            
            
                                    
            
            
                | 190 |  |  |      * @param string $comparator | 
            
                                                                                                            
                            
            
                                    
            
            
                | 191 |  |  |      * @return bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 192 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 193 |  |  |     protected function evaluateCompare($x, $y, string $comparator): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 194 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 195 |  |  |         // enforce strong comparison for comparing two objects | 
            
                                                                                                            
                            
            
                                    
            
            
                | 196 |  |  |         if ($comparator === '==' && is_object($x) && is_object($y)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 197 |  |  |             $comparator = '==='; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 198 |  |  |         } elseif ($comparator === '!=' && is_object($x) && is_object($y)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 199 |  |  |             $comparator = '!=='; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 200 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 201 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 202 |  |  |         switch ($comparator) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 203 |  |  |             case '==': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 204 |  |  |                 $x = ($x == $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 205 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 206 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 207 |  |  |             case '===': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 208 |  |  |                 $x = ($x === $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 209 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 210 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 211 |  |  |             case '!=': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 212 |  |  |                 $x = ($x != $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 213 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 214 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 215 |  |  |             case '!==': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 216 |  |  |                 $x = ($x !== $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 217 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 218 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 219 |  |  |             case '<=': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 220 |  |  |                 $x = ($x <= $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 221 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 222 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 223 |  |  |             case '>=': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 224 |  |  |                 $x = ($x >= $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 225 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 226 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 227 |  |  |             case '<': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 228 |  |  |                 $x = ($x < $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 229 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 230 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 231 |  |  |             case '>': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 232 |  |  |                 $x = ($x > $y); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 233 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 234 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 235 |  |  |             case '%': | 
            
                                                                                                            
                            
            
                                    
            
            
                | 236 |  |  |                 if (!is_numeric($x) || !is_numeric($y)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 237 |  |  |                     $x = 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 238 |  |  |                 } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 239 |  |  |                     $x = (($x + 0) % ($y + 0)); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 240 |  |  |                 } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 241 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 242 |  |  |                 break; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 243 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 244 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 245 |  |  |         return (bool) $x; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 246 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 247 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 248 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 249 |  |  |      * Convert argument strings to their equivalents. Needed to handle strings with a boolean meaning. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 250 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 251 |  |  |      * Must be public and static as it is used from inside cached templates. | 
            
                                                                                                            
                            
            
                                    
            
            
                | 252 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 253 |  |  |      * @param mixed $value Value to be converted to boolean | 
            
                                                                                                            
                            
            
                                    
            
            
                | 254 |  |  |      * @return boolean | 
            
                                                                                                            
                            
            
                                    
            
            
                | 255 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 256 |  |  |     protected function convertToBoolean($value): bool | 
            
                                                                                                            
                            
            
                                    
            
            
                | 257 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 258 |  |  |         if (is_string($value)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 259 |  |  |             return (strtolower($value) !== 'false' && !empty($value)); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 260 |  |  |         } elseif (is_array($value)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 261 |  |  |             return !empty($value); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 262 |  |  |         } elseif ($value instanceof \Countable) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 263 |  |  |             return count($value) > 0; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 264 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 265 |  |  |         return (bool) $value; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 266 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 267 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 268 |  |  |  | 
            
                        
If you return a value from a function or method, it should be a sub-type of the type that is given by the parent type f.e. an interface, or abstract method. This is more formally defined by the Lizkov substitution principle, and guarantees that classes that depend on the parent type can use any instance of a child type interchangably. This principle also belongs to the SOLID principles for object oriented design.
Let’s take a look at an example:
Our function
my_functionexpects aPostobject, and outputs the author of the post. The base classPostreturns a simple string and outputting a simple string will work just fine. However, the child classBlogPostwhich is a sub-type ofPostinstead decided to return anobject, and is therefore violating the SOLID principles. If aBlogPostwere passed tomy_function, PHP would not complain, but ultimately fail when executing thestrtouppercall in its body.