Cobalt
Cobalt is part of the E-sites iOS Suite.
The E-sites Swift iOS API Client used for standard restful API's with default support for OAuth2.
Installation
##Swift PM
package.swift dependency:
.package(url: "https://github.com/e-sites/cobalt.git", from: "7.0.0"),and to your application/library target, add "Cobalt" to your dependencies, e.g. like this:
.target(name: "BestExampleApp", dependencies: ["Cobalt"]),Implementation
Extend the Cobalt class to use it in your own API client.
Initialization
import Cobalt
class APIClient: Cobalt.Client {
static let `default` = APIClient()
private init() {
let config = Cobalt.Config {
$0.authentication.clientID = "my_oauth_client_id"
$0.authentication.clientSecret = "my_oauth_client_secret"
$0.host = "https://api.domain.com"
}
super.init(config: config)
}
}
Making requests
APIClient uses Promises by google internally for handling the responses for a request
Promises
class APIClient: Cobalt.Client {
// ...
func users() -> Promise<[User]> {
let request = Cobalt.Request {
$0.path = "/users"
$0.parameters = [
"per_page": 10
]
}
return self.request(request).then { json: JSON -> Promise<[User]> in
let users = try json.map(to: [User].self)
return Promise(users)
}.catch { error in
print("Error: \(error)")
}
}
}Caching
To utilize disk caching out of the box add the following line to your Podfile:
pod 'Cobalt/Cache'
And implement it like this:
class APIClient: Cobalt.Client {
// ...
func users() -> Promise<[User]> {
let request = Cobalt.Request {
$0.path = "/users"
$0.cachingPolicy = .expires(seconds: 60 * 60 * 24) // expires after 1 day
}
return self.request(request).then { json: JSON -> Promise<[User]> in
let users = try json.map(to: [User].self)
return Promise(users)
}.catch { error in
print("Error: \(error)")
}
}
}To clear the entire cache:
APIClientInstance.cache.clearAll()RxSwift
Extend the above class with:
import RxSwift
extension Reactive where Base: Cobalt.Client {
func users() -> Single<[User]> {
return self.users().asSingle()
}
}And use it like so:
APIClient.default.rx.users() // ... rxswift etc.Regular closures
Not in the need for Promises or RxSwift, you can also use regular closures:
extension Promise {
func closure(_ handler: @escaping ((Value?, Error?) -> Void)) {
self.then { value in
handler(value, nil)
}.catch { error in
handler(nil, error)
}
}
}And then use it like this:
APIClient.default.users().closure { users, error
// ... Handle it
}OAuth2
If you want to login a user using the OAuth2 protocol, use the login() function from the Cobalt class.
Internally it will handle the retrieval and refreshing of the provided access_token:
func login(email: String, password: String) -> Promise<Void>You can also use other options of authentication
password
If you want to retrieve the user profile, you need the .oauth2(.password) authenication, that way the request will only succeed if the user has requested an access_token through the login() function.
If the access_token is expired, Cobalt will automatically refresh it, using the refresh_token
class APIClient: Cobalt.Client {
// ...
func profile() -> Promise<User> {
let request = Cobalt.Request({
$0.authentication = .oauth2(.password)
$0.path = "/user/profile"
})
return request(request).then { json -> Promise<User> in
let user = try json["data"].map(to: User.self)
return Promise(user)
}
}
}
client_credentials
You have to provide the .oauth2(.clientCredentials) authentication for the Cobalt.Request
class APIClient: Cobalt.Client {
// ...
func register(email: String, password: String) -> Promise<Void> {
let request = Cobalt.Request({
$0.httpMethod = .post
$0.path = "/register"
$0.authentication = .oauth2(.clientCredentials)
$0.parameters = [
"email": email,
"password": password
]
})
return request(request).then { json -> Promise<Void> in
return Promise(())
}
}This way Cobalt will know that the request needs a client_credentials grant_type with an access-token.
If the user already has an access_token with that grant_type, Cobalt will use it. Else it will request a new access_token for you
Clearing the access_token
To remove the access_token from its memory and keychain, use:
func clearAccessToken()Development
Just open Cobalt.xcodeproj