How to obtain photo data/metadata after being picked in PHPickerViewController?

Question

Created Jul ’20

Replies 6

Boosts 1

Views 5.9k

Participants 6

Hi there,

In the app I work on, I am being tasked with a requirement to present the user their device photos using a PHPickerViewController.

Once selected, I need access to:

The raw image data
The file name of the image
The creation date of the image

This is simple to do with a PHAsset if I had full access to the user's photos - I could use the PHPickerViewController result value which includes photoIdentifiers to query PhotoKit for the PHAssets. However, there is no guarantee that I have full access. Additionally if the user has granted no access or limited access, and the limited selection does not include the photos being selected in the PHPickerViewController, I won't be able to query for them. (I tried this, and as expected the result of the query is nil, which makes sense).

The UIImage that I can obtain is only a proxy of the original image data (missing things like exif data, etc), so that is not sufficient for the user case my app has. Assuming there was an item provider for data, I'd still need to get information such as file name and creation date as well though.

So, is there a way to obtain this information?

Thanks!

Boost

Answer 1

Mr. Brightside OP

Jul ’20

If you check the NSItemProvider from PHPickerResult, you will see that it has "suggestedName" property. This will be your file name.

I don't have any additional information about raw image data and creation date, sorry.

0

Answer 2

Engineer OP

Apple

Aug ’20

As mentioned above you can get the suggested name for the file name.
If you want the raw image data, you can load the file representation or the data respresentation.

1

Answer 3

Zatman OP

Aug ’20

For some strange reason, when I use 'file representation' loading, the app does not have the proper permissions to work on the file at the returned URL. I had to copy the file to a temp location and work on the copied URL. Not sure if this is intentional or an oversight bug. Below is the sort of code I needed to use:

NSString *allFiles = @"public.item";
_ _block PHPickerResult *blockResult = result;

_ _block NSMutableArray <NSURL *>*blockFileURLArray = [NSMutableArray array];

for (PHPickerResult *result in results){

[result.itemProvider loadFileRepresentationForTypeIdentifier: allFiles
completionHandler:^(NSURL * Nullable url,
NSError * Nullable error) {
if (error) {
// TODO
// show alert

NSLog(@"error %@", error);

} else {

// for some reason, I cannot access the url for uploading
// need to copy the file to a temp location

NSString *filename = url.lastPathComponent;

NSString *path = [NSString temporaryPathByUsingFileName: [filename stringByDeletingPathExtension]
pathExtension: filename.pathExtension];

NSURL *copyURL = [NSURL fileURLWithPath: path];

NSError *copyError;

[NSFileManager.defaultManager copyItemAtURL: url
toURL: copyURL
error: &copyError];

if (copyError) {
NSLog(@"%@ copyError %@", self, error);
} else {

// can now do stuff to the file at copyURL
// store it in the files array

[blockFileURLArray addObject: copyURL];

}

}
}

// do stuff on the gathered files in blockFileURLArray

0

Answer 4

Engineer OP

Apple

Aug ’20

Is the error only happening when running in the Simulator or also on a device?

0

Answer 5

michaelfransen OP

Aug ’20

I am also trying to get the creation date and the location of where the photo was taken. We were able to do this with access to the PHAsset. Is there a way to get this information using the PHPickerViewController?

1

Answer 6

ppix OP

Sep ’20

You should be able to access the image's metadata using ImageIO.
Specifically look at CGImageSourceCopyPropertiesAtIndex(..)

0