CODEWITHSUNDEEP
swiftpropertiesstaticoverridingprotocols
Matias Contreras
Matias Contreras

Reputation: 500

Protocol extension to struct and overwritable

I want to be able to decode different objects that come from the server with different date formats and for that I came up with this protocol:

public protocol DateFormatProtocol{
    var dateFormat : String {get}
}

public protocol CodableWithDateFormat : Codable, DateFormatProtocol{
    static var dateFormat: String {get}// = "DatFormat"
}

public extension CodableWithDateFormat{
    public static var dateFormat: String { return "Base date format" }
}

So when I need to I could override the property in each struct that needs a different date format but I don't want eavery struct to override the default date format given on the extension of the protocol. Is there any way for me being able to write this? : 

struct Struct1 : CodableWithDateFormat{
    var dateFormat: String { return "Overwritten Date Format" }
    let prop1 : String
    let prop2 : Int
}

struct Struct2 : CodableWithDateFormat{ //Type 'Struct2' does not conform to protocol 'DateFormatProtocol'
    let prop1 : String
    let prop2 : Int
}

Upvotes: 1

Views: 252

Answers (1)

Kamran
Kamran

Reputation: 15248

You need to match the declaration for dateFormat in DateFormatProtocol as below,

public protocol DateFormatProtocol {
    static var dateFormat: String { get }
}

public protocol CodableWithDateFormat: Codable, DateFormatProtocol {}

public extension CodableWithDateFormat {
    public static var dateFormat: String { return "Base date format" }
}

struct Struct1: CodableWithDateFormat {
    public static var dateFormat: String { return "Overwritten Date Format" }
    let prop1: String
    let prop2: Int
}

struct Struct2: CodableWithDateFormat {
    let prop1: String
    let prop2: Int
}

Upvotes: 1

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