{"action":"closed","issue":{"url":"https://api.github.com/repos/ReactiveCocoa/ReactiveCocoa/issues/2321","labels_url":"https://api.github.com/repos/ReactiveCocoa/ReactiveCocoa/issues/2321/labels{/name}","comments_url":"https://api.github.com/repos/ReactiveCocoa/ReactiveCocoa/issues/2321/comments","events_url":"https://api.github.com/repos/ReactiveCocoa/ReactiveCocoa/issues/2321/events","html_url":"https://github.com/ReactiveCocoa/ReactiveCocoa/issues/2321","id":105308576,"number":2321,"title":"[Question] Chain two operation Best Practice ?","user":{"login":"yiplee","id":1432077,"avatar_url":"https://avatars.githubusercontent.com/u/1432077?v=3","gravatar_id":"","url":"https://api.github.com/users/yiplee","html_url":"https://github.com/yiplee","followers_url":"https://api.github.com/users/yiplee/followers","following_url":"https://api.github.com/users/yiplee/following{/other_user}","gists_url":"https://api.github.com/users/yiplee/gists{/gist_id}","starred_url":"https://api.github.com/users/yiplee/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/yiplee/subscriptions","organizations_url":"https://api.github.com/users/yiplee/orgs","repos_url":"https://api.github.com/users/yiplee/repos","events_url":"https://api.github.com/users/yiplee/events{/privacy}","received_events_url":"https://api.github.com/users/yiplee/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-09-08T06:05:23Z","updated_at":"2015-09-16T13:35:37Z","closed_at":"2015-09-16T13:35:37Z","body":"Hello , \r\n\r\nI have a viewController that has two type of async tasks :\r\n\r\n\r\n1, upload image picked from imagePickerController \r\n```objc\r\n- (RACSignal* ) uploadImage:(UIImage:)image\r\n// send a url when completed\r\n```\r\n- whenever a new image picked , upload the new one and cancle the last uncompleted `upload image task`.\r\n\r\n2, update user profile by touching a button\r\n```objc\r\n- (RACSignal*) updateProfile\r\n```\r\n- if there is a running `uploading image task` , wait for the `upload image task's` complete event. \r\n\r\nAny suggestion?\r\nThanks very much!\r\n"}}