ios - Image.file() Showing Blank When Specified File Was Explicitly Created

Question

In the iOS variant of my Flutter app, when I explicitly create a .jpg file using

    File(path.join(filePath, fileName))
      ..createSync(recursive: true)
      ..writeAsBytesSync(buffer);

the widget that renders the file (by calling Image.file(), passing to it the file as an argument) results with a blank image.

No exception was thrown indicating that the file was not found or file contents was invalid. Its behaving as if the file is blank, but when I browse to the file using Finder, the file is there and when I click on the image, Preview renders the expected image.

When the same code is executed when the image comes from the device camera or device gallery, it works and when the same code is executed in the Android variant with the file being explicitly created, it works too.

The only thing I can think of is that it has to do with creating the image deep inside my iOS simulator directory structure

ie-/Users/joselitope/Library/Developer/CoreSimulator/Devices/F2AE8082-E670-498B-B2C6-9A83BE1855A4/data/Containers/Data/Application/7B01A347-69AE-4A1F-8567-7FCC256013F5/tmp/comp_image_cropper_2CC9EEFB-A126-4811-BD80-485B4C41F3A2-18523-00001C049E5AAE85.jpg

but again, the file is visible using Finder so this may not be the reason.

Maybe I have to set certain permissions when creating the file in iOS or perhaps settings applicable to iOS in my pubspec.yaml?

All help is greatly appreciated.

My environment is as follows: Catelina 10.15.7, Flutter 1.22.5 channel stable, XCode 12.3, Simulator: iPhone 12 Pro Max - 14.3,

Answer 1

Someone posted a suggestion that prompted me to look into this problem again. (That someone has since removed his suggestion so I am unable to thank him.)

Anyways, when I tried to reproduce the problem it wasnt happening anymore even in the exact use case it was happening previously.

So the question remains is why and the only thing I ruled out that it wasnt a race condition as this code has been running on Android for quite some time on various devices.

This is what I could come up with:

Knowing the filepath I was writing to, I realized that I was writing to the app's /tmp directory which iOS periodically empties out. I am thinking that I shouldn't be putting stuff there. Instead, I've been writing to the app's documents directory and it hasnt happened since.

The initial /tmp directory was chosen for me by a package I was using and since it was so long and Im new to iOS, I didn't really look into it all that much, caring only that the file was there, which it was.

Anyways, keeping my fingers crossed that the fix sticks.