Nil response after assigning data from Alamofire request

Question

I am attempting to assign the data from my Alamofire request to a dictionary of parameters, but it always shows up as nil.

var params = SomeParams()
params.addUserIds([currentUserID, partnerUserID])
params.name = name

Alamofire.request(url!, method: .get)
            .validate()
            .responseData(completionHandler: { (responseData) in
             DispatchQueue.main.async {                                              
                 params.coverImage = responseData.data!  
             }                                                       
})

// NIL RESPONSE
print(params)

I know that it's because the Alamofire call is being done in the background so I attempted to call the main thread and assign it. Yet it still doesn't work. Any ideas?

Alamofire requests work asynchronously. Move the `print` line into the `DispatchQueue` closure right after assigning `responseData.data!` — vadian, Feb 13 '19 at 18:18
@butter_baby use completion handler or check out this: https://stackoverflow.com/a/42484670/1240676 — AtheistP3ace, Feb 13 '19 at 18:19
If you are wanting to use params outside of the request you will need to use `DispatchGroups` — Bot, Feb 13 '19 at 18:25

score -1 · Answer 1 · answered Feb 13 '19 at 18:19

-1

You need to perform work (like print) in the completionHandler. There is no need of DispatchQueue

var params = SomeParams()
params.addUserIds([currentUserID, partnerUserID])
params.name = name

Alamofire.request(url!, method: .get)
            .validate()
            .responseData(completionHandler: { (responseData) in

                 params.coverImage = responseData.data!  
                 print(params)

})

answered Feb 13 '19 at 18:19

pkc456

8,256
34
50
104

Actually there is a need for the dispatchqueue, his example above isn't actually setting an image but if he was setting the `UIImage` he will need to do it on the main queue. He may also want the params outside of the request completion so this doesn't resolve that problem – Bot Feb 13 '19 at 18:21
@Bot: I thought `params` is a model class where `coverImage` is a property name. – pkc456 Feb 13 '19 at 18:22

Nil response after assigning data from Alamofire request

1 Answers1