How do I use RxSwift with AlamoFire and SwiftyJSON? - swift

Question

I'm trying to learn RxSwift and currently I'm trying to use it in relation to AlamoFire and SwiftyJSON, that is, to observe when JSON has been downloaded so that I can parse it. I have working code for getting JSON:
guard let myURL = URL(string: "https://api.myjson.com/bins/e5gjk") else { return }
var myArray = [People]()
let myObserver = Observable.from(myArray)
Alamofire.request(myURL, method: .get)
.validate()
.responseJSON{ response in
guard response.result.isSuccess else {
print("Error")
return
}
let json = JSON(response.result.value)
for i in 0...json["employees"].count {
let people = People()
people.name = json["employees"][i]["firstName"].stringValue
people.job = json["employees"][i]["job"].stringValue
myArray.append(people)
}
for i in myArray {
print(i.name)
print(i.job)
}
}
myObserver.subscribe(onNext: {
print($0)
}, onError: { error in
print(error)
}, onCompleted: {
print("completed")
}, onDisposed: {
print("disposed")
}).disposed(by: DisposeBag())
As you can see, I have parsed the JSON as well. I guess that the point of RX here would be to use the data in onNext once it has been parsed, correct? Or have I misunderstood its purpose?
Anyway, I have an observer on myArray: let myObserver = Observable.from(myArray). In my head, subscribe onNext should be triggered as soon as myArray gets data, but that's not happening. What happens is that completed is run immediately, then the JSON networking and parsing takes place. The subscription is not triggered when myArray gets new data. Have I missed something or misunderstood RX's purpose?
EDIT
Or wait, should the whole JSON handling and parsing be in the onNext?

Answer 1

you need to create your observer. This should work :
let observer = Observable<People>.create { (observer) -> Disposable in
Alamofire.request(myURL, method: .get)
.validate()
.responseJSON { response in
guard response.result.isSuccess else {
print("Error")
observer.on(.error(response.result.error!))
return
}
let json = JSON(response.result.value)
for i in 0...json["employees"].count {
let people = People()
people.name = json["employees"][i]["firstName"].stringValue
people.job = json["employees"][i]["job"].stringValue
observer.on(.next(people))
myArray.append(people)
}
observer.on(.completed)
for i in myArray {
print(i.name)
print(i.job)
}
}
return Disposables.create()
}
then you can subscribe to your observer of type Observable<People>
observer.subscribe { (event) in
switch event {
case .next(let people):
print(people.job)
print(people.name)
case .error(let error):
print("error \(error.localizedDescription)")
case .completed:
print("completed")
}
}.disposed(by: disposeBag)