raulriera / cacher Goto Github PK

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