{"__v":4,"_id":"56740128f79ca90d00ad2f65","category":{"__v":7,"_id":"567400638565060d009a86fb","pages":["567400df22cd7e0d00fada7f","56740103f65d9c0d002e3d5e","5674010f47f7010d005bff1a","56740128f79ca90d00ad2f65","5674014947f7010d005bff1c","5674015622cd7e0d00fada81","5674016058c4890d00bb5558"],"project":"5672fc989996590d00c22c65","version":"5672fc989996590d00c22c68","sync":{"url":"","isSync":false},"reference":false,"createdAt":"2015-12-18T12:47:31.547Z","from_sync":false,"order":2,"slug":"available-operations","title":"Available Operations"},"project":"5672fc989996590d00c22c65","user":"5654ea8be0d82b0d00ab5747","version":{"__v":7,"_id":"5672fc989996590d00c22c68","project":"5672fc989996590d00c22c65","createdAt":"2015-12-17T18:19:04.699Z","releaseDate":"2015-12-17T18:19:04.699Z","categories":["5672fc999996590d00c22c69","567301169d4c060d009da8b3","56730183547bee0d00997d1a","5673018a06b19d0d0010691b","567301b53054630d00fe9288","567400638565060d009a86fb","5674017bf79ca90d00ad2f67"],"is_deprecated":false,"is_hidden":false,"is_beta":false,"is_stable":true,"codename":"","version_clean":"2.5.0","version":"2.5.0"},"updates":[],"next":{"pages":[],"description":""},"createdAt":"2015-12-18T12:50:48.095Z","link_external":false,"link_url":"","githubsync":"","sync_unique":"","hidden":false,"api":{"results":{"codes":[]},"settings":"","auth":"required","params":[],"url":""},"isReference":false,"order":4,"body":"`GroupOperation` can be used to execute multiple `NSOperation` instances on a private queue. This is a very powerful class and probably the second most commonly used after `BlockOperation`. Advanced techniques will be discussed in a later section, here we will cover the basics.\n[block:api-header]\n{\n  \"type\": \"basic\",\n  \"title\": \"Direct usage\"\n}\n[/block]\nInitialize a `GroupOperation` with an array of `NSOperation` instances. Dependencies set on the operations will also be respected.\n[block:code]\n{\n  \"codes\": [\n    {\n      \"code\": \"let group = GroupOperation(operations: opOne, opTwo, opThree)\\ngroup.addObserver(FinishedObserver { op in\\n    // the group has finished, meaning all operations have finsihed.\\n})\\nqueue.addOperation(group)\",\n      \"language\": \"swift\"\n    }\n  ]\n}\n[/block]\nOnce the group has started, but has not finished, it is possible to add more operations to the group.\n[block:code]\n{\n  \"codes\": [\n    {\n      \"code\": \"group.addOperation(opFour)\\ngroup.addOperations([opFive, opSix])\",\n      \"language\": \"swift\"\n    }\n  ]\n}\n[/block]\n\n[block:callout]\n{\n  \"type\": \"info\",\n  \"title\": \"Cancellation\",\n  \"body\": \"Cancelling the group will cancel all operations in the queue.\"\n}\n[/block]","excerpt":"","slug":"group-operation","type":"basic","title":"Group Operation"}
`GroupOperation` can be used to execute multiple `NSOperation` instances on a private queue. This is a very powerful class and probably the second most commonly used after `BlockOperation`. Advanced techniques will be discussed in a later section, here we will cover the basics. [block:api-header] { "type": "basic", "title": "Direct usage" } [/block] Initialize a `GroupOperation` with an array of `NSOperation` instances. Dependencies set on the operations will also be respected. [block:code] { "codes": [ { "code": "let group = GroupOperation(operations: opOne, opTwo, opThree)\ngroup.addObserver(FinishedObserver { op in\n // the group has finished, meaning all operations have finsihed.\n})\nqueue.addOperation(group)", "language": "swift" } ] } [/block] Once the group has started, but has not finished, it is possible to add more operations to the group. [block:code] { "codes": [ { "code": "group.addOperation(opFour)\ngroup.addOperations([opFive, opSix])", "language": "swift" } ] } [/block] [block:callout] { "type": "info", "title": "Cancellation", "body": "Cancelling the group will cancel all operations in the queue." } [/block]