My CompletionHandler will not execute. Why?

Question

I have the following code:

document?.open { success in
        if success {
            print("file opened")
            self.consumed = self.document?.consumed
        } else {
            print("file read failure")
        }
    }

As can be seen, I have a print for both success and failure. But neither prints.

The reasonable question is the file is not there, not readable or something. Therefore, I have added before this code the following:

if document != nil {
        print("not nil")
        let asString = document?.fileURL.path
        let toast = FileManager.default.fileExists(atPath: asString!)
        if toast {
            print("file exist")
        } else {
            print("file does not exist")
        }
    } else {
        print("nil")
    }
 if FileManager.default.isReadableFile(atPath: (document?.fileURL.path)!)
    {
        print("readable")
    }
    else
    {
        print("not readable")
    }

This indicates for me that it is: not nil, exists, and readable.

Is there sometime I am missing to have this completion code not execute? It would be great to be able to open the file, but I think the fact that it is not operating is the first step.

Of note about the file. It is a file that is read from the bundle and copied to Documents directory. I have looked at the attributes of the file and have found nothing odd.

either your `document` is _actually_ `nil` or you are using a _beta_ SDK what cannot be considered reliable because it is _beta_. — holex, Aug 03 '18 at 13:16
One more additional question. Could it be an issue with the copy? I was looking for some from of release to make sure the file is available. That does not seem to be necessary in Swift. Regardless, I am suspicious that the copy is not completing or somehow corrupting the file. However, so far evaluation of attributes shows nothing, — jz_, Aug 03 '18 at 13:57

score 0 · Answer 1 · answered Aug 03 '18 at 12:48

0

Try to replace document?.open with document!.open, or use a guard let to really make sure document is not nil. Cause if document is nil the whole call is being skipped.

Here you can read up on Optional Chaining.

answered Aug 03 '18 at 12:48

Fabian

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document!.open give no different behavior. Not sure I know how to use the guard with a completionHandler. – jz_ Aug 03 '18 at 13:47
@jz_ Hm thats weird. The guard would just have checked that document is not nil. What type is document? – Fabian Aug 03 '18 at 13:49
Purpose,document is a JSON file saved as a custom UTI format. Is that what you are asking. I guess, one check would be to go back to a JSON ext and read that way, See if the custom designation is the problem. – jz_ Aug 03 '18 at 14:00
You lost me on UTI format, but if the open does custom opening stuff that could be the culprit too of course. – Fabian Aug 03 '18 at 14:02
Basically you can declare your own extension type. – jz_ Aug 03 '18 at 14:03
And open() parses that for you? If it works by parsing as JSON it could limit the scope of what could have gone wrong. – Fabian Aug 03 '18 at 14:04
If it would execute. But it does not even begin to execute. I am following a lecture from the Stanford iTunes series. Seems to work there, but does not even execute for me. – jz_ Aug 03 '18 at 14:06
@jz_ That sounds pretty frustrating. I found reports from 2013 and 2015 where happened sth similar, but whether its related or not dunno. Good luck! – Fabian Aug 03 '18 at 14:10
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/177357/discussion-between-jz-and-purpose). – jz_ Aug 03 '18 at 14:12

My CompletionHandler will not execute. Why?

1 Answers1