DataService

public class DataService

The DataService class provides functionality for interfacing with the Peter Symonds College data service.

This includes authentication and retrieval of information from the Timetable, Find, Room Timetable, and User services.

Properties

  • A typealias used only in authenticateFromSavedDetails(completion:) to simplify the declaration.

    Declaration

    Swift

    public typealias AuthenticationCompletion = (

    Parameters

    error

    An error if one occurred during the request; otherwise nil.

  • A typealias used only in exchangeCodeForToken(_:completion:) in order to simplify the declaration of the completion block.

    Declaration

    Swift

    public typealias ExchangeCompletion = (

    Parameters

    result

    The authentication result.
    error

    An error, if one occurred.

  • Singleton instance of DataService.

    Declaration

    Swift

    public static var shared = DataService()

  • The URL used for retrieving an access token.

    Declaration

    Swift

    public var getAccessTokenURL: URL

  • The redirect URL, passed to the Symonds Data Service in authentication requests.

    Apart from being required by the Data Service, this redirect URL enables a return to the host application after authenticating externally.

    Declaration

    Swift

    public let redirectURL = URL(string: "app://com.sorenmortensen.SymondsStudentApp")!

  • A pair of keys used for authentication with the Symonds Data Service.

    These keys are secret and are therefore loaded from a JSON file that is copied into the main bundle at build time.

    Declaration

    Swift

    private let keys: (clientID: String, secret: String)? =

  • The result of the most recent authentication.

    Declaration

    Swift

    private var authenticationResult: AuthenticationResult?

  • A shared session used for sending network requests.

    Declaration

    Swift

    private let session = URLSession(configuration: .default)

  • The URL where authentication requests are sent.

    Declaration

    Swift

    private let authURL = URL(string: "https://data.psc.ac.uk/oauth/v2/auth")!

  • The URL where token exchange requests are sent.

    Declaration

    Swift

    private let tokenURL = URL(string: "https://data.psc.ac.uk/oauth/v2/token")!

Types

  • The result of an authentication request sent to the Symonds Data Service.

    See more

    Declaration

    Swift

    public struct AuthenticationResult

  • A type of grant that can be used to request an access token from the Symonds Data Service.

    See more

    Declaration

    Swift

    public enum GrantType: String

  • An error.

    See more

    Declaration

    Swift

    public enum Error: Swift.Error

Initialisers

  • A private initialiser to ensure that access to DataService is only through the shared singleton.

    Declaration

    Swift

    private init()

Authentication

  • Attempts to use saved authentication details from Keychain to authenticate with the Data Service.

    Declaration

    Swift

    public func authenticateFromSavedDetails(completion: @escaping AuthenticationCompletion)

    Parameters

    completion

    Called when the request completes.

  • Exchanges an authorisation code for an access token.

    Declaration

    Swift

    public func exchangeCodeForToken(_ code: String,
                                     grantType: GrantType,
                                     completion: @escaping ExchangeCompletion)

    Parameters

    code

    The authorisation code to exchange.
    completion

    Called when the network request completes.

  • Generates an HTTP POST string to exchange an authorisation code for an access token.

    Throws

    An error of type AuthenticationError in the event of a relevant error.

    Declaration

    Swift

    private func generateExchangePOSTString(with code: String,
                                            grantType: GrantType) throws -> String

    Parameters

    code

    The authorisation code to use for authentication when requesting a token.

    Return Value

    The generated string.

  • Creates an AuthenticationResult instance from a JSON object returned by the Symonds Data Service.

    Throws

    Throws errors of type AuthenticationError in the event of a relevant error.

    Declaration

    Swift

    private func serializeLoginResponse(from data: Data) throws -> AuthenticationResult

    Parameters

    data

    The data returned by the Symonds Data Service.