The problem:

fileExistsAtPath always returns NO (even though the app container definitely contains the file).

We used to save some files in the Cache folder and persist the file path into a sqlite table. The URL to the file to be saved was stored in NSURL and .path would return the path. Here is an example:

/var/mobile/Containers/Data/Application/A586EFC6-EBA4-499F-A3F5-BA505CA44696/Library/Caches/OurFiles/ea347f7c-e25d-4538-9f0a-f83b22a66a7c

Later, we would check if the file is still there using fileExistsAtPath:

if ([[NSFileManager defaultManager] fileExistsAtPath:path])

We tested it and it all worked just fine. But a couple of weeks ago we accidentally discovered that fileExistsAtPath always returned NO.

There are at least two problems with our approach:

• Caches folder might change for future iOS versions.
• Unlike absoluteString, NSUrl path does not contain the scheme.

The solution:

Now we only store the name of the file (and not the full path) and generate the path dynamically with NSSearchPathForDirectoriesInDomains and it works just fine.