Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php  | 
            ||
| 46 | class FederatedService { | 
            ||
| 47 | |||
| 48 | |||
| 49 | /** @var string */  | 
            ||
| 50 | private $userId;  | 
            ||
| 51 | |||
| 52 | /** @var IL10N */  | 
            ||
| 53 | private $l10n;  | 
            ||
| 54 | |||
| 55 | /** @var ConfigService */  | 
            ||
| 56 | private $configService;  | 
            ||
| 57 | |||
| 58 | /** @var CirclesService */  | 
            ||
| 59 | private $circlesService;  | 
            ||
| 60 | |||
| 61 | /** @var FederatedLinksRequest */  | 
            ||
| 62 | private $federatedLinksRequest;  | 
            ||
| 63 | |||
| 64 | /** @var CirclesMapper */  | 
            ||
| 65 | private $dbCircles;  | 
            ||
| 66 | |||
| 67 | /** @var MembersMapper */  | 
            ||
| 68 | private $dbMembers;  | 
            ||
| 69 | |||
| 70 | /** @var ClientService */  | 
            ||
| 71 | private $clientService;  | 
            ||
| 72 | |||
| 73 | /** @var MiscService */  | 
            ||
| 74 | private $miscService;  | 
            ||
| 75 | |||
| 76 | |||
| 77 | /**  | 
            ||
| 78 | * CirclesService constructor.  | 
            ||
| 79 | *  | 
            ||
| 80 | * @param $userId  | 
            ||
| 81 | * @param IL10N $l10n  | 
            ||
| 82 | * @param ConfigService $configService  | 
            ||
| 83 | * @param DatabaseService $databaseService  | 
            ||
| 84 | * @param CirclesService $circlesService  | 
            ||
| 85 | * @param FederatedLinksRequest $federatedLinksRequest  | 
            ||
| 86 | * @param string $serverHost  | 
            ||
| 87 | * @param ClientService $clientService  | 
            ||
| 88 | * @param MiscService $miscService  | 
            ||
| 89 | */  | 
            ||
| 90 | public function __construct(  | 
            ||
| 114 | |||
| 115 | |||
| 116 | /**  | 
            ||
| 117 | * linkCircle()  | 
            ||
| 118 | *  | 
            ||
| 119 | * link to a circle.  | 
            ||
| 120 | * Function will check if settings allow Federated links between circles, and the format of  | 
            ||
| 121 | * the link ($remote). If no exception, a request to the remote circle will be initiated  | 
            ||
| 122 | * using requestLinkWithCircle()  | 
            ||
| 123 | *  | 
            ||
| 124 | * $remote format: <circle_name>@<remote_host>  | 
            ||
| 125 | *  | 
            ||
| 126 | * @param int $circleId  | 
            ||
| 127 | * @param string $remote  | 
            ||
| 128 | *  | 
            ||
| 129 | * @throws Exception  | 
            ||
| 130 | * @throws FederatedCircleLinkFormatException  | 
            ||
| 131 | * @throws CircleTypeNotValid  | 
            ||
| 132 | * @throws MemberIsNotAdminException  | 
            ||
| 133 | *  | 
            ||
| 134 | * @return FederatedLink  | 
            ||
| 135 | */  | 
            ||
| 136 | 	public function linkCircle($circleId, $remote) { | 
            ||
| 156 | |||
| 157 | |||
| 158 | /**  | 
            ||
| 159 | * requestLinkWithCircle()  | 
            ||
| 160 | *  | 
            ||
| 161 | * Using CircleId, function will get more infos from the database.  | 
            ||
| 162 | * Will check if author is not admin and initiate a FederatedLink, save it  | 
            ||
| 163 | * in the database and send a request to the remote circle using requestLink()  | 
            ||
| 164 | * If any issue, entry is removed from the database.  | 
            ||
| 165 | *  | 
            ||
| 166 | * @param $circleId  | 
            ||
| 167 | * @param $remote  | 
            ||
| 168 | *  | 
            ||
| 169 | * @return FederatedLink  | 
            ||
| 170 | * @throws Exception  | 
            ||
| 171 | */  | 
            ||
| 172 | 	private function requestLinkWithCircle($circleId, $remote) { | 
            ||
| 201 | |||
| 202 | |||
| 203 | /**  | 
            ||
| 204 | * @param string $remote  | 
            ||
| 205 | *  | 
            ||
| 206 | * @return string  | 
            ||
| 207 | */  | 
            ||
| 208 | View Code Duplication | 	private function generateLinkRemoteURL($remote) { | 
            |
| 215 | |||
| 216 | /**  | 
            ||
| 217 | * @param string $remote  | 
            ||
| 218 | *  | 
            ||
| 219 | * @return string  | 
            ||
| 220 | */  | 
            ||
| 221 | View Code Duplication | 	private function generatePayloadDeliveryURL($remote) { | 
            |
| 228 | |||
| 229 | |||
| 230 | /**  | 
            ||
| 231 | * requestLink()  | 
            ||
| 232 | *  | 
            ||
| 233 | *  | 
            ||
| 234 | * @param Circle $circle  | 
            ||
| 235 | * @param FederatedLink $link  | 
            ||
| 236 | *  | 
            ||
| 237 | * @return int  | 
            ||
| 238 | * @throws Exception  | 
            ||
| 239 | */  | 
            ||
| 240 | 	private function requestLink(Circle $circle, FederatedLink &$link) { | 
            ||
| 276 | |||
| 277 | |||
| 278 | 	private function parsingRequestLinkResult($result) { | 
            ||
| 306 | |||
| 307 | |||
| 308 | /**  | 
            ||
| 309 | * Create a new link into database and assign the correct status.  | 
            ||
| 310 | *  | 
            ||
| 311 | * @param Circle $circle  | 
            ||
| 312 | * @param FederatedLink $link  | 
            ||
| 313 | *  | 
            ||
| 314 | * @return bool  | 
            ||
| 315 | */  | 
            ||
| 316 | 	public function initiateLink(Circle $circle, FederatedLink &$link) { | 
            ||
| 328 | |||
| 329 | |||
| 330 | /**  | 
            ||
| 331 | * @param $circleId  | 
            ||
| 332 | * @param $uniqueId  | 
            ||
| 333 | *  | 
            ||
| 334 | * @return FederatedLink  | 
            ||
| 335 | */  | 
            ||
| 336 | 	public function getLink($circleId, $uniqueId) { | 
            ||
| 339 | |||
| 340 | |||
| 341 | 	public function initiateRemoteShare($uniqueId) { | 
            ||
| 364 | |||
| 365 | }  | 
            
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: