For a detail information about using "Cacher", checkout the article "Caching anything in iOS".
Drag and drop the Cacher/
folder into your project.
Add the following to your Cartfile:
github "raulriera/Cacher"
Add this repo to your dependencies.
For a quick TL;DR check out the sample project at CacherDemo
. It will guide you with the simplest caching possible, persisting string values.
If you like to get your hands dirty, continue reading as we are going to go into detail about how this works.
public protocol Cachable {
var fileName: String { get }
func transform() -> Data
}
It all comes down to this simple protocol, that has only two requirements fileName
which represents the unique name to store in the filesystem, and transform
which is the Data
representation of what you wish to import. Using the magic of Swift 4 Codable
, we can skip the transform
implementation and use the implicit one declared right here.
After we implement conform to Cachable
and Codable
, anything can be stored in the filesystem using the persist:item:completion
method.
But, let's see a more complex example
struct CachableMovies: Cachable, Codable {
let store: String
let movies: [Movie]
var fileName: String {
return "movies-\(store)"
}
init(store: String, movies: [Movie]) {
self.store = store
self.movies = movies
}
}
struct Movie: Codable {
enum CodingKeys : String, CodingKey {
case title = "movie_title"
case description = "movie_description"
case url = "movie_url"
}
let title: String
let description: String
let url: URL
}
The previous code is all we need to store a collection of movies into the filesystem. 🎉 Now we can simply use the persist
method like this.
Cacher(destination: .temporary).persist(item: CachableMovies(store: "USA", movies: myArrayOfMovies)) { url, error in
// Completion handler when the process finishes
}
Raul Riera, @raulriera