Complex classes like ByPropertyIdArray 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 ByPropertyIdArray, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 46 | class ByPropertyIdArray extends ArrayObject { |
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| 47 | |||
| 48 | /** |
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| 49 | * @var array[]|null |
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| 50 | */ |
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| 51 | private $byId = null; |
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| 52 | |||
| 53 | /** |
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| 54 | * @see ArrayObject::__construct |
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| 55 | * |
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| 56 | * @param PropertyIdProvider[]|Traversable|null $input |
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| 57 | */ |
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| 58 | public function __construct( $input = null ) { |
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| 59 | parent::__construct( (array)$input ); |
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| 60 | } |
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| 61 | |||
| 62 | /** |
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| 63 | * Builds the index for doing look-ups by property id. |
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| 64 | * |
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| 65 | * @since 0.2 |
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| 66 | */ |
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| 67 | public function buildIndex() { |
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| 81 | |||
| 82 | /** |
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| 83 | * Checks whether id indexed array has been generated. |
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| 84 | * |
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| 85 | * @throws RuntimeException |
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| 86 | */ |
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| 87 | private function assertIndexIsBuild() { |
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| 88 | if ( $this->byId === null ) { |
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| 89 | throw new RuntimeException( 'Index not build, call buildIndex first' ); |
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| 90 | } |
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| 91 | } |
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| 92 | |||
| 93 | /** |
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| 94 | * Returns the property ids used for indexing. |
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| 95 | * |
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| 96 | * @since 0.2 |
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| 97 | * |
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| 98 | * @return PropertyId[] |
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| 99 | * @throws RuntimeException |
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| 100 | */ |
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| 101 | public function getPropertyIds() { |
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| 102 | $this->assertIndexIsBuild(); |
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| 103 | |||
| 104 | return array_map( |
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| 105 | function( $serializedPropertyId ) { |
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| 106 | return new PropertyId( $serializedPropertyId ); |
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| 107 | }, |
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| 108 | array_keys( $this->byId ) |
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| 109 | ); |
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| 110 | } |
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| 111 | |||
| 112 | /** |
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| 113 | * Returns the objects featuring the provided property id in the index. |
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| 114 | * |
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| 115 | * @since 0.2 |
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| 116 | * |
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| 117 | * @param PropertyId $propertyId |
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| 118 | * |
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| 119 | * @throws OutOfBoundsException |
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| 120 | * @throws RuntimeException |
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| 121 | * @return PropertyIdProvider[] |
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| 122 | */ |
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| 123 | public function getByPropertyId( PropertyId $propertyId ) { |
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| 124 | $this->assertIndexIsBuild(); |
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| 125 | |||
| 126 | if ( !( array_key_exists( $propertyId->getSerialization(), $this->byId ) ) ) { |
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| 127 | throw new OutOfBoundsException( "Object with propertyId \"$propertyId\" not found" ); |
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| 128 | } |
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| 129 | |||
| 130 | return $this->byId[$propertyId->getSerialization()]; |
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| 131 | } |
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| 132 | |||
| 133 | /** |
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| 134 | * Returns the absolute index of an object or false if the object could not be found. |
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| 135 | * @since 0.5 |
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| 136 | * |
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| 137 | * @param PropertyIdProvider $object |
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| 138 | * |
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| 139 | * @return bool|int |
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| 140 | * @throws RuntimeException |
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| 141 | */ |
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| 142 | public function getFlatArrayIndexOfObject( $object ) { |
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| 143 | $this->assertIndexIsBuild(); |
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| 144 | |||
| 145 | $i = 0; |
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| 146 | foreach ( $this as $o ) { |
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| 147 | if ( $o === $object ) { |
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| 148 | return $i; |
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| 149 | } |
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| 150 | $i++; |
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| 151 | } |
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| 152 | return false; |
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| 153 | } |
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| 154 | |||
| 155 | /** |
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| 156 | * Returns the objects in a flat array (using the indexed form for generating the array). |
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| 157 | * @since 0.5 |
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| 158 | * |
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| 159 | * @return PropertyIdProvider[] |
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| 160 | * @throws RuntimeException |
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| 161 | */ |
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| 162 | public function toFlatArray() { |
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| 163 | $this->assertIndexIsBuild(); |
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| 164 | |||
| 165 | $array = array(); |
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| 166 | foreach ( $this->byId as $objects ) { |
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| 167 | $array = array_merge( $array, $objects ); |
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| 168 | } |
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| 169 | return $array; |
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| 170 | } |
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| 171 | |||
| 172 | /** |
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| 173 | * Returns the absolute numeric indices of objects featuring the same property id. |
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| 174 | * |
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| 175 | * @param PropertyId $propertyId |
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| 176 | * |
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| 177 | * @throws RuntimeException |
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| 178 | * @return int[] |
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| 179 | */ |
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| 180 | private function getFlatArrayIndices( PropertyId $propertyId ) { |
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| 181 | $this->assertIndexIsBuild(); |
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| 182 | |||
| 183 | $propertyIndices = array(); |
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| 184 | $i = 0; |
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| 185 | |||
| 186 | foreach ( $this->byId as $serializedPropertyId => $objects ) { |
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| 187 | if ( $serializedPropertyId === $propertyId->getSerialization() ) { |
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| 188 | $propertyIndices = range( $i, $i + count( $objects ) - 1 ); |
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| 189 | break; |
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| 190 | } else { |
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| 191 | $i += count( $objects ); |
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| 192 | } |
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| 193 | } |
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| 194 | |||
| 195 | return $propertyIndices; |
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| 196 | } |
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| 197 | |||
| 198 | /** |
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| 199 | * Moves an object within its "property group". |
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| 200 | * |
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| 201 | * @param PropertyIdProvider $object |
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| 202 | * @param int $toIndex Absolute index within a "property group". |
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| 203 | * |
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| 204 | * @throws OutOfBoundsException |
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| 205 | */ |
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| 206 | private function moveObjectInPropertyGroup( $object, $toIndex ) { |
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| 207 | $currentIndex = $this->getFlatArrayIndexOfObject( $object ); |
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| 208 | |||
| 209 | if ( $toIndex === $currentIndex ) { |
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| 210 | return; |
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| 211 | } |
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| 212 | |||
| 213 | $propertyId = $object->getPropertyId(); |
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| 214 | |||
| 215 | $numericIndices = $this->getFlatArrayIndices( $propertyId ); |
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| 216 | $lastIndex = $numericIndices[count( $numericIndices ) - 1]; |
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| 217 | |||
| 218 | if ( $toIndex > $lastIndex + 1 || $toIndex < $numericIndices[0] ) { |
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| 219 | throw new OutOfBoundsException( 'Object cannot be moved to ' . $toIndex ); |
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| 220 | } |
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| 221 | |||
| 222 | if ( $toIndex >= $lastIndex ) { |
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| 223 | $this->moveObjectToEndOfPropertyGroup( $object ); |
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| 224 | } else { |
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| 225 | $this->removeObject( $object ); |
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| 226 | |||
| 227 | $propertyGroup = array_combine( |
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| 228 | $this->getFlatArrayIndices( $propertyId ), |
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| 229 | $this->getByPropertyId( $propertyId ) |
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| 230 | ); |
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| 231 | |||
| 232 | $insertBefore = $propertyGroup[$toIndex]; |
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| 233 | $this->insertObjectAtIndex( $object, $this->getFlatArrayIndexOfObject( $insertBefore ) ); |
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| 234 | } |
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| 235 | } |
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| 236 | |||
| 237 | /** |
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| 238 | * Moves an object to the end of its "property group". |
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| 239 | * |
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| 240 | * @param PropertyIdProvider $object |
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| 241 | */ |
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| 242 | private function moveObjectToEndOfPropertyGroup( $object ) { |
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| 257 | |||
| 258 | /** |
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| 259 | * Removes an object from the array structures. |
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| 260 | * |
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| 261 | * @param PropertyIdProvider $object |
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| 262 | */ |
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| 263 | private function removeObject( $object ) { |
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| 264 | $flatArray = $this->toFlatArray(); |
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| 265 | $this->exchangeArray( $flatArray ); |
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| 266 | $this->offsetUnset( array_search( $object, $flatArray ) ); |
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| 267 | $this->buildIndex(); |
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| 268 | } |
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| 269 | |||
| 270 | /** |
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| 271 | * Inserts an object at a specific index. |
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| 272 | * |
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| 273 | * @param PropertyIdProvider $object |
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| 274 | * @param int $index Absolute index within the flat list of objects. |
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| 275 | */ |
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| 276 | private function insertObjectAtIndex( $object, $index ) { |
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| 277 | $flatArray = $this->toFlatArray(); |
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| 278 | |||
| 279 | $this->exchangeArray( array_merge( |
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| 280 | array_slice( $flatArray, 0, $index ), |
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| 281 | array( $object ), |
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| 282 | array_slice( $flatArray, $index ) |
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| 283 | ) ); |
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| 284 | |||
| 285 | $this->buildIndex(); |
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| 286 | } |
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| 287 | |||
| 288 | /** |
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| 289 | * @param PropertyId $propertyId |
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| 290 | * @param int $toIndex |
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| 291 | */ |
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| 292 | private function movePropertyGroup( PropertyId $propertyId, $toIndex ) { |
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| 293 | if ( $this->getPropertyGroupIndex( $propertyId ) === $toIndex ) { |
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| 294 | return; |
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| 295 | } |
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| 296 | |||
| 297 | $insertBefore = null; |
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| 298 | |||
| 299 | $oldIndex = $this->getPropertyGroupIndex( $propertyId ); |
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| 300 | $byIdClone = $this->byId; |
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| 301 | |||
| 302 | // Remove "property group" to calculate the groups new index: |
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| 303 | unset( $this->byId[$propertyId->getSerialization()] ); |
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| 304 | |||
| 305 | if ( $toIndex > $oldIndex ) { |
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| 306 | // If the group shall be moved towards the bottom, the number of objects within the |
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| 307 | // group needs to be subtracted from the absolute toIndex: |
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| 308 | $toIndex -= count( $byIdClone[$propertyId->getSerialization()] ); |
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| 309 | } |
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| 310 | |||
| 311 | foreach ( $this->getPropertyIds() as $pId ) { |
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| 312 | // Accepting other than the exact index by using <= letting the "property group" "latch" |
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| 313 | // in the next slot. |
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| 314 | if ( $toIndex <= $this->getPropertyGroupIndex( $pId ) ) { |
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| 315 | $insertBefore = $pId; |
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| 316 | break; |
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| 317 | } |
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| 318 | } |
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| 319 | |||
| 320 | $serializedPropertyId = $propertyId->getSerialization(); |
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| 321 | $this->byId = array(); |
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| 322 | |||
| 323 | foreach ( $byIdClone as $serializedPId => $objects ) { |
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| 324 | $pId = new PropertyId( $serializedPId ); |
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| 325 | if ( $pId->equals( $propertyId ) ) { |
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| 326 | continue; |
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| 327 | } elseif ( $pId->equals( $insertBefore ) ) { |
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| 328 | $this->byId[$serializedPropertyId] = $byIdClone[$serializedPropertyId]; |
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| 329 | } |
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| 330 | $this->byId[$serializedPId] = $objects; |
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| 331 | } |
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| 332 | |||
| 333 | if ( $insertBefore === null ) { |
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| 334 | $this->byId[$serializedPropertyId] = $byIdClone[$serializedPropertyId]; |
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| 335 | } |
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| 336 | |||
| 337 | $this->exchangeArray( $this->toFlatArray() ); |
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| 338 | } |
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| 339 | |||
| 340 | /** |
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| 341 | * Returns the index of a "property group" (the first object in the flat array that features |
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| 342 | * the specified property). Returns false if property id could not be found. |
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| 343 | * |
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| 344 | * @param PropertyId $propertyId |
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| 345 | * |
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| 346 | * @return bool|int |
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| 347 | */ |
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| 348 | private function getPropertyGroupIndex( PropertyId $propertyId ) { |
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| 349 | $i = 0; |
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| 350 | |||
| 351 | foreach ( $this->byId as $serializedPropertyId => $objects ) { |
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| 352 | $pId = new PropertyId( $serializedPropertyId ); |
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| 353 | if ( $pId->equals( $propertyId ) ) { |
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| 354 | return $i; |
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| 355 | } |
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| 356 | $i += count( $objects ); |
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| 357 | } |
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| 358 | |||
| 359 | return false; |
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| 360 | } |
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| 361 | |||
| 362 | /** |
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| 363 | * Moves an existing object to a new index. Specifying an index outside the object's "property |
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| 364 | * group" will move the object to the edge of the "property group" and shift the whole group |
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| 365 | * to achieve the designated index for the object to move. |
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| 366 | * @since 0.5 |
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| 367 | * |
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| 368 | * @param PropertyIdProvider $object |
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| 369 | * @param int $toIndex Absolute index where to move the object to. |
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| 370 | * |
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| 371 | * @throws OutOfBoundsException |
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| 372 | * @throws RuntimeException |
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| 373 | */ |
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| 374 | public function moveObjectToIndex( $object, $toIndex ) { |
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| 375 | $this->assertIndexIsBuild(); |
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| 376 | |||
| 377 | if ( !in_array( $object, $this->toFlatArray() ) ) { |
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| 378 | throw new OutOfBoundsException( 'Object not present in array' ); |
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| 379 | } elseif ( $toIndex < 0 || $toIndex > count( $this ) ) { |
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| 380 | throw new OutOfBoundsException( 'Specified index is out of bounds' ); |
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| 381 | } elseif ( $this->getFlatArrayIndexOfObject( $object ) === $toIndex ) { |
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| 382 | return; |
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| 383 | } |
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| 384 | |||
| 385 | // Determine whether to simply reindex the object within its "property group": |
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| 386 | $propertyIndices = $this->getFlatArrayIndices( $object->getPropertyId() ); |
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| 387 | |||
| 388 | if ( in_array( $toIndex, $propertyIndices ) ) { |
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| 389 | $this->moveObjectInPropertyGroup( $object, $toIndex ); |
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| 390 | } else { |
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| 391 | $edgeIndex = ( $toIndex <= $propertyIndices[0] ) |
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| 392 | ? $propertyIndices[0] |
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| 393 | : $propertyIndices[count( $propertyIndices ) - 1]; |
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| 394 | |||
| 395 | $this->moveObjectInPropertyGroup( $object, $edgeIndex ); |
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| 396 | $this->movePropertyGroup( $object->getPropertyId(), $toIndex ); |
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| 397 | } |
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| 398 | |||
| 399 | $this->exchangeArray( $this->toFlatArray() ); |
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| 400 | } |
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| 401 | |||
| 402 | /** |
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| 403 | * Adds an object at a specific index. If no index is specified, the object will be append to |
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| 404 | * the end of its "property group" or - if no objects featuring the same property exist - to the |
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| 405 | * absolute end of the array. |
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| 406 | * Specifying an index outside a "property group" will place the new object at the specified |
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| 407 | * index with the existing "property group" objects being shifted towards the new object. |
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| 408 | * |
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| 409 | * @since 0.5 |
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| 410 | * |
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| 411 | * @param PropertyIdProvider $object |
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| 412 | * @param int|null $index Absolute index where to place the new object. |
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| 413 | * |
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| 414 | * @throws RuntimeException |
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| 415 | */ |
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| 416 | public function addObjectAtIndex( $object, $index = null ) { |
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| 417 | $this->assertIndexIsBuild(); |
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| 418 | |||
| 419 | $propertyId = $object->getPropertyId(); |
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| 420 | $validIndices = $this->getFlatArrayIndices( $propertyId ); |
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| 421 | |||
| 422 | if ( count( $this ) === 0 ) { |
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| 423 | // Array is empty, just append object. |
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| 424 | $this->append( $object ); |
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| 425 | } elseif ( empty( $validIndices ) ) { |
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| 426 | // No objects featuring that property exist. The object may be inserted at a place |
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| 427 | // between existing "property groups". |
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| 428 | $this->append( $object ); |
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| 429 | if ( $index !== null ) { |
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| 430 | $this->buildIndex(); |
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| 431 | $this->moveObjectToIndex( $object, $index ); |
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| 432 | } |
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| 433 | } else { |
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| 434 | // Objects featuring the same property as the object which is about to be added already |
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| 435 | // exist in the array. |
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| 436 | $this->addObjectToPropertyGroup( $object, $index ); |
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| 437 | } |
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| 438 | |||
| 439 | $this->buildIndex(); |
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| 440 | } |
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| 441 | |||
| 442 | /** |
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| 443 | * Adds an object to an existing property group at the specified absolute index. |
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| 444 | * |
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| 445 | * @param PropertyIdProvider $object |
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| 446 | * @param int|null $index |
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| 447 | * |
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| 448 | * @throws OutOfBoundsException |
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| 449 | */ |
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| 450 | private function addObjectToPropertyGroup( $object, $index = null ) { |
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| 487 | |||
| 488 | } |
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| 489 |
There are different options of fixing this problem.
If you want to be on the safe side, you can add an additional type-check:
If you are sure that the expression is traversable, you might want to add a doc comment cast to improve IDE auto-completion and static analysis:
Mark the issue as a false-positive: Just hover the remove button, in the top-right corner of this issue for more options.