iOS import files into my application

Question

I am creating an iOS application through which users can print the files on their device. From my application, I can access the files on the device though the DocumentPicker provided by other apps such as iCloud Drive, Dropbox, etc.

Now, I want to add a functionality where user can share the file with my application through an other application. I created an Action Extension for that. For example, if I select an Image in the Photos application and select Share I get my extension in the Share sheet and when I select it, I also get the URL of the file. Next, I am creating a zip file of this file to send it to my server. But the issue is, the zip file is always empty. The code I am using is as below:

In Action Extension's viewDidLoad()

if itemProvider.hasItemConformingToTypeIdentifier(kUTTypeImage as String) {
    itemProvider.loadItemForTypeIdentifier(kUTTypeImage as String, options: nil, 
        completionHandler: { (image, error) in
            NSOperationQueue.mainQueue().addOperationWithBlock {
                print("Image: \(image.debugDescription)")
                //Image: Optional(file:///Users/guestUser/Library/Developer/CoreSimulator/Devices/00B81632-041E-47B1-BACD-2F15F114AA2D/data/Media/DCIM/100APPLE/IMG_0004.JPG)
                print("Image class: \(image.dynamicType)")
                //Image class: Optional<NSSecureCoding>
                self.filePaths.append(image.debugDescription)
                let zipPath = self.createZip(filePaths)
                print("Zip: \(zipPath)")
            }
         })
}

And my createZip function is as follows:

func createZipWithFiles(filePaths: [AnyObject]) -> String {
    let zipPath = createZipPath()  //Creates an unique zip file name

    let success = SSZipArchive.createZipFileAtPath(zipPath, withFilesAtPaths: filePaths)

    if success {
        return zipPath
    }
    else {
        return "zip prepation failed"
    }
}

Is there a way that I can create a zip of the shared files?

Is `SSZipArchive` returning an error? Are you sure you have write access to the `zipPath` and read access to all of the paths in `filePaths`? — JAL, Apr 20 '16 at 13:26
No it does not give any error. It creates a zip file at `zipPath`, hence I have write access at `zipPath`. And, the files in `filePaths` are image files coming from the default Photos application. In the logs it says that the file does not exist at the mentioned position but I can see the file if I navigate through the terminal (for simulator). — Prerak Sola, Apr 20 '16 at 13:31
Using `image.debugDescription` is not the way to get a file path to the image. First, what is the actual type of `image` in the completion handler? What is the output of `image.debugDescription`? — rmaddy, Apr 22 '16 at 16:26
@rmaddy: image is of type `NSSecureCoding` and the output of `image.debugDescription` is somethings like`fie:///Users/xxx/Library/Developer/CoreSimulator/Devices/---xx-xx-xx/data/Media/DCIM/100APPLE/IMG_0004.jpg` — Prerak Sola, Apr 25 '16 at 07:44
You have post 2 func. In the first you use self.createZip(filePaths), and in the second you post func createZipWithFiles, but i dont see any createZip method.. — Alessandro Ornano, Apr 25 '16 at 10:48
@AlessandroOrnano: As I have mentioned in the comments, `createZip()` function just creates a unique file name. So it returns a string like `xxx-yy-zzz.zip`. — Prerak Sola, Apr 25 '16 at 13:35
@PrerakSola Update your question with the actual and complete output of the line `print("Image: \(image.debugDescription)")`. — rmaddy, Apr 25 '16 at 14:35
@rmaddy: Added the complete output in the comment below the print statement. — Prerak Sola, Apr 25 '16 at 14:42
OK, now add the output of `print("Image class: \(image.dynamicType)")`. — rmaddy, Apr 25 '16 at 14:48

score 3 · Accepted Answer · answered Apr 25 '16 at 15:08

Your primary issue is that you are blindly adding image.debugDescription to an array that is expecting a file path. The output of image.debugDescription isn't at all a valid file path. You need to use a proper function on the image to obtain the actual file path.

But image is declared to have a type of NSSecureCoding. Based on the output of image.debugDescription, it seems that image is really of type NSURL. So you need to convert image to an NSURL using a line like:

if let photoURL = image as? NSURL {
}

Once you have the NSURL, you can use the path property to get the actual needed path.

So your code becomes:

if itemProvider.hasItemConformingToTypeIdentifier(kUTTypeImage as String) {
    itemProvider.loadItemForTypeIdentifier(kUTTypeImage as String, options: nil, 
        completionHandler: { (image, error) in
            if let photoURL = image as? NSURL {
                NSOperationQueue.mainQueue().addOperationWithBlock {
                    let photoPath = photoURL.path
                    print("photoPath: \(photoPath)")
                    self.filePaths.append(photoPath)
                    let zipPath = self.createZip(filePaths)
                    print("Zip: \(zipPath)")
                }
            }
    })
}

Hint: Never use debugDescription for anything other than a print statement. Its output is just some string that could contain just about any information and that output can change from one iOS version to the next.

Thank you for the answer. Before this, as a workaround, I was creating a temporary image using `NSData` in my app's sandbox and than copying that image to the zip file to upload to the server. But your way saves the processing and memory overhead of creating an extra image. — Prerak Sola, Apr 25 '16 at 15:52
@rmaddy, I implemented shared extension in my app, In iOS 13, my share extension app can not open main app to receive shared file/image because UIApplication.shared is unavailable now. Previous all version works fine. So, how could developer receive/import data from different sources ? Suppose i want to open a file to my app from gmail or drive, any workaround ? — Jamshed Alam, Feb 23 '20 at 02:48

iOS import files into my application

1 Answers1