Image written through WriteToFile command is missing after app rerun - ios

Question

I am writing an app which downloads image from my server and stores them locally for offline viewing. The codes I use to store the image locally are shown below. Apart from storing the image, I am also able to read the image from the path (which I stored separately).
However when I re-run my code from Xcode to the iPhone (without uninstalling the app from the phone), the stored image file would be missing. Is this expected? Would I face similar issue when my app has been released on App Store and when the user updates the app? Is there a way to keep the file persistent when I re-run them when I update some codes in Xcode?
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *imagePath =[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"file.jpeg",]];
if (![imageData writeToFile:imagePath atomically:YES])
{
// Handling when there is an error
NSLog(#"Failed to store file at path %#",imagePath);
stored.text = #"";
}
else
{ // Handling when write is successful
NSLog(#"Imaged stored path is %#",imagePath);
stored.text = imagePath;
}
[imageView setImage:image];
The code to read the image is shown below:
NSString *imagePathToRead = stored.text;
NSLog(#"Retrieve image from %#",imagePathToRead);
UIImage *image = [UIImage imageWithContentsOfFile:imagePathToRead];
[imageView setImage:image];

Answer 1

I am posting the answer here from rmaddy which solved the issue I was facing. I am posting here so that others can benefit if they are facing similar issue.
For the storing portion:
The stored.text should never store the full path:
stored.text = imagePath;
Instead I should store #"file.jpeg" only.
For the Read portion:
I should always regenerate the full path below when I wanted to read the path instead of the code below:
NSString *imagePathToRead = stored.text;
The corrected codes are:
NSString *imagePathToRead = stored.text;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *imagePath =[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:imagePathToRead]];
NSLog(#"Retrieve image from %#",imagePath);
UIImage *image = [UIImage imageWithContentsOfFile:imagePath];
This solved the issue and the image is able to be read even though the app is re-installed through Xcode.