Is possible get file in main app from my share extension save file?

Question

Is possible get save documents file from my share extension?

I try to build the share extension, the share extension can get the file path. I write a funciton to save the file to my Documents folder.

I need to get the file from my main app. But I found I save the file from share extension path is

/var/mobile/Containers/Data/PluginKitPlugin/9EBF8983-E1DE-49E2-8589-CEE7305EB644/Documents/xxx.png

I using the main app to get the document path is below

/var/mobile/Containers/Data/Application/CFD67CD9-5A8A-473E-8ECF-FC1C1CF18098/Documents

the folder id is not same.

Is possible get the file from share extension saved file? Thank you very much.

Answer 1

You're right. Applications and extensions cannot share individual directories due to sandboxing limitations. That's why their directories are different – they're running in different processes.

Nevertheless, App Groups allow shared directories. You can access the App Group's directory by using the NSFileManager like this:

let groupPath = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.com.example.documents")

Any target matching the group entitlement will be able to read/write from/to the shared directory (or container). So, they aren't actually part of your application's or extension's process. It might also be interesting to take a look at iOS' File System Basics, in order to understand the architecture of App Group containers.

As suggested by others, I also highly recommend to read the App Extension Guide which explains the usage of containers quite well.

Answer 2

I try to write the code using objective-c in share extension.

In my share extension :

 +(NSURL*)getSharedContainerURLPath
 {
     NSFileManager *fm = [NSFileManager defaultManager];

     NSURL *groupContainerURL = [fm containerURLForSecurityApplicationGroupIdentifier:APP_GROUP];

     return groupContainerURL;
 }

 -(void) saveFileAction{
       NSString *docPath = [ClassName getSharedContainerURLPath].absoluteString;

     NSString * fileNamePathString = [docPath stringByAppendingPathComponent:[self generateMyFileName]];
     NSError *err;
BOOL fileSaveSuccess = [myFileData writeToFile: fileNamePathString
                                               options:NSDataWritingFileProtectionComplete
                                                 error:&err];


 }

Then my main App to load the folder data code:

 NSString * folderPath = [ClassName getSharedContainerURLPath].absoluteString;
 NSArray *directoryContent = [[NSFileManager defaultManager]      contentsOfDirectoryAtPath:folderPath error:NULL];
NSLog(@"directoryContent:%@",directoryContent);

I found the directory content always got the null.

I had set the APP Groups in the extension and main target.

My share extension save log file path below:

share extension trace log below:

 write file success:0 / error:Error Domain=NSCocoaErrorDomain Code=4      "The file “0421_224358.png” doesn’t exist." UserInfo=     {NSFilePath=file:/private/var/mobile/Containers/Shared/AppGroup/ACDE7845-     E0E3-45C3-893F-6F6978EC3534/0421_224358.png, NSUnderlyingError=0x174251ac0      {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}

My Main app trace the folder path below:

file:///private/var/mobile/Containers/Shared/AppGroup/ACDE7845-E0E3-45C3-893F-6F6978EC3534/

I don't known why it save error .

Have anyone can give some hint ? thank you very mch.