Cache files properly with Core API for iOS and Swift

[vanya e.]

Hello!

I'm now working on the simple Dropbox viewer application.
Currently I'm using "download to Documents folder" method like that: 

if let data =  NSData(contentsOfFile: destinationPath) {

            print("File already cached")

 } else {

            print("File not cached, processing cache operation...")

            Manager.client.loadFile(filePath, intoPath: destinationPath)

  }

Files are downloading properly, but, I think, that it's a wrong way to cache files. 
So, the question is: is there a way to cache images with standard API tools and, for example, store them with NSCache or something similar?

P.S. It's not essentially important, actually, in which programming language will be answer, I'm simply trying to understand the principles, if they exist

Thanks!

[Greg-DB]

The Dropbox API and SDK themselves don't offer local caching like this, so you will need to implement it in your app's code if your app needs caching. Actual caching strategies and algorithms are beyond the scope of just Dropbox/Dropbox API support, so I can't offer much help with that in general. Perhaps someone here can offer some advice or direct you to some good resources though.

One thing I will note specific to Dropbox though, is to check the rev for the value. The remote Dropbox file could have changed after you originally downloaded it, meaning the copy you have locally is out of date.