Complex classes like Statement 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 Statement, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 19 | final class Statement |
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| 20 | { |
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| 21 | private $id; |
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| 22 | private $verb; |
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| 23 | private $actor; |
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| 24 | private $object; |
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| 25 | private $result; |
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| 26 | private $authority; |
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| 27 | private $created; |
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| 28 | private $stored; |
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| 29 | private $context; |
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| 30 | private $attachments; |
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| 31 | private $version; |
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| 32 | |||
| 33 | /** |
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| 34 | * @param Attachment[]|null $attachments |
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| 35 | */ |
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| 36 | public function __construct(StatementId $id = null, Actor $actor, Verb $verb, StatementObject $object, Result $result = null, Actor $authority = null, \DateTime $created = null, \DateTime $stored = null, Context $context = null, array $attachments = null, string $version = null) |
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| 50 | |||
| 51 | public function withId(StatementId $id = null): self |
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| 58 | |||
| 59 | public function withActor(Actor $actor): self |
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| 66 | 4 | ||
| 67 | 4 | public function withVerb(Verb $verb): self |
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| 74 | |||
| 75 | public function withObject(StatementObject $object): self |
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| 82 | |||
| 83 | public function withResult(Result $result = null): self |
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| 90 | 3 | ||
| 91 | /** |
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| 92 | * Creates a new Statement based on the current one containing an Authority |
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| 93 | * that asserts the Statement true. |
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| 94 | */ |
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| 95 | public function withAuthority(Actor $authority = null): self |
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| 102 | |||
| 103 | public function withCreated(\DateTime $created = null): self |
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| 110 | 3 | ||
| 111 | public function withStored(\DateTime $stored = null): self |
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| 118 | |||
| 119 | public function withContext(Context $context = null): self |
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| 126 | |||
| 127 | /** |
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| 128 | 2 | * @param Attachment[]|null $attachments |
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| 129 | */ |
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| 130 | 2 | public function withAttachments(array $attachments = null): self |
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| 137 | |||
| 138 | public function withVersion(string $version = null): self |
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| 145 | |||
| 146 | /** |
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| 147 | * Returns the Statement's unique identifier. |
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| 148 | */ |
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| 149 | public function getId(): ?StatementId |
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| 153 | |||
| 154 | /** |
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| 155 | * Returns the Statement's {@link Verb}. |
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| 156 | */ |
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| 157 | public function getVerb(): Verb |
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| 161 | |||
| 162 | /** |
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| 163 | * Returns the Statement's {@link Actor}. |
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| 164 | */ |
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| 165 | public function getActor(): Actor |
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| 169 | |||
| 170 | 2 | /** |
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| 171 | * Returns the Statement's {@link StatementObject}. |
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| 172 | 2 | */ |
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| 173 | public function getObject(): StatementObject |
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| 177 | |||
| 178 | /** |
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| 179 | * Returns the {@link Activity} {@link Result}. |
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| 180 | */ |
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| 181 | public function getResult(): ?Result |
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| 185 | |||
| 186 | 1 | /** |
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| 187 | 1 | * Returns the Authority that asserted the Statement true. |
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| 188 | */ |
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| 189 | 1 | public function getAuthority(): ?Actor |
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| 193 | |||
| 194 | /** |
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| 195 | * Returns the timestamp of when the events described in this statement |
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| 196 | * occurred. |
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| 197 | */ |
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| 198 | public function getCreated(): ?\DateTime |
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| 202 | 2 | ||
| 203 | /** |
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| 204 | 2 | * Returns the timestamp of when this statement was recorded by the LRS. |
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| 205 | */ |
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| 206 | public function getStored(): ?\DateTime |
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| 210 | |||
| 211 | /** |
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| 212 | * Returns the context that gives the statement more meaning. |
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| 213 | */ |
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| 214 | public function getContext(): ?Context |
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| 218 | 2 | ||
| 219 | /** |
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| 220 | * @return Attachment[]|null |
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| 221 | */ |
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| 222 | 2 | public function getAttachments(): ?array |
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| 226 | 2 | ||
| 227 | public function getVersion(): ?string |
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| 231 | |||
| 232 | /** |
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| 233 | * Tests whether or not this Statement is a void Statement (i.e. it voids |
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| 234 | 2 | * another Statement). |
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| 235 | */ |
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| 236 | public function isVoidStatement(): bool |
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| 240 | |||
| 241 | /** |
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| 242 | 2 | * Returns a {@link StatementReference} for the Statement. |
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| 243 | */ |
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| 244 | public function getStatementReference(): StatementReference |
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| 248 | |||
| 249 | /** |
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| 250 | 1 | * Returns a Statement that voids the current Statement. |
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| 251 | */ |
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| 252 | public function getVoidStatement(Actor $actor): self |
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| 261 | |||
| 262 | /** |
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| 263 | * Checks if another statement is equal. |
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| 264 | * |
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| 265 | * Two statements are equal if and only if all of their properties are equal. |
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| 266 | */ |
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| 267 | public function equals(Statement $statement): bool |
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| 343 | } |
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| 344 |
Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: