Convert string to enum without a value swift

Question

I'm making a permissions system, and the emum below shows the possible permissions for an advance. I get the permissions from the server as a string: advance.answer.view. Is there any way to convert that string into the enum Advance.Answer.View?

enum Advance {

        case View, Edit

        enum Answer { case View, Edit }
        enum Ride { case View, Edit }
        enum Contact { case View, Edit }
        enum Document { case View, Edit }
        enum Guest { case View, Edit }
        enum Section { case View, Edit, Create }
        enum Member { case View, Edit }
        enum Flight { case View, Edit }
        enum Location { case View, Edit }
        enum Time { case View, Edit }
        enum Event { case View, Edit }

    }

qwerty_so · Accepted Answer · 2015-03-30 20:37:34Z

1

You need to make the enum a String rawvalue like

enum Answer:String {
  case View = "View"
  case Edit = "Edit"
  init(s:String) {
    if s == "xy" { self = .View}
    else { self = .Edit }
  }
  mutating func fromString(s:String) {
    if s == "xy" { self = .View}
  }
}

var answer1 = Answer(rawValue:"View")!
var answer2 = Answer(s:"x")
answer2.fromString("xy")

edited Mar 30, 2015 at 20:37

answered Mar 30, 2015 at 20:32

qwerty_so

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4 Comments

jamespick Over a year ago

Is there any way around this? I have so many values and it seems redudant.

qwerty_so Over a year ago

You can write a fromString function.

jamespick Over a year ago

How would that work? Could u post some code? I can't think of how such a function would work in an efficient way.

qwerty_so Over a year ago

See my changes in the answer

dimpiax · Accepted Answer · 2016-01-31 21:19:43Z

1

You can modify your visual structure into:

enum Advance {
    case Answer(view: Bool, edit: Bool)
}

// usage
Advance.Answer(view: false, edit: true)

UPD. Another case:

enum Advance: String {
    case View = "view", Edit = "edit"

    static func getEnumType(value: String) -> EnumProtocol.Type {
        switch value {
            case "contact":
                return Contact.self

            default:
                return Answer.self
        }
    }

    enum Answer: String, EnumProtocol {
        init(rawValue: String) {
            switch rawValue {
                case "edit":
                    self = .Edit

                default:
                    self = .View
            }
        }

        case View = "view", Edit = "edit"
    }

    enum Contact: String, EnumProtocol {
        init(rawValue: String) {
            switch rawValue {
                case "write":
                    self = .Write

                case "edit":
                    self = .Edit

                default:
                    self = .View
            }
        }

        case View = "view", Edit = "edit", Write = "write"
    }
}

EnumProtocol you can extend with get function of rawValue.

protocol EnumProtocol {
    init(rawValue: String)
}

Update at (31/01/2016)

Usage:

Advance.getEnumType("contact").init(rawValue: "write") // Advance.Contact.Write
Advance.getEnumType("unknown").init(rawValue: "abc") // Advance.Answer.View

edited Jan 31, 2016 at 21:19

answered Mar 30, 2015 at 21:03

dimpiax

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4 Comments

jamespick Over a year ago

how could I then check the values true or false

dimpiax Over a year ago

enum Advance { case Time(view: Bool, edit: Bool) } let someEnum: Advance = .Time(view: true, edit: false) switch someEnum { case .Time(let a, let b): println("Time. view: (a) edit: (b)") default: break }

jamespick Over a year ago

how would i check if I can view the time in an if statement though @dimpiax

dimpiax Over a year ago

Through "if statement" can't.

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