CODEWITHSUNDEEP
swiftmethodsstaticprotocolsswift-protocols
Pierre
Pierre

Reputation: 11633

Protocol static var used in method

I have this swift code :

protocol Table {
    static var tableName: String { get }
}

class User: Table {
      internal static var tableName = "user"
}

I know would like to construct methods with Table protocol parameters. Something like :

func doSomethingFrom(table: Table) {
  print(table.tableName)
}

doSomethingFrom(table: User) // prints "user"

Is there a way to achieve this simply ?

Upvotes: 0

Views: 506

Answers (2)

broekhaas
broekhaas

Reputation: 1

Since the value of tableName will be the same for all instances of User (because it is static) you can do:

func doSomethingFrom(table: Table) {
    print(User.tableName)
    // OR:
    print(type(of: table).tableName) 
}

Make sure though this is what you really want.

Upvotes: 0

Rob Napier
Rob Napier

Reputation: 299265

This is the syntax you're looking for. You need to pass the type itself by appending .self. This is to prevent mistakes (since talking about types directly is kind of rare, but easy to do by accident). And you need to take a parameter of the type itself rather than an instance of that type.

func doSomethingFrom(table: Table.Type) {
    print(table.tableName)
}

doSomethingFrom(table: User.self) // prints "user"

Upvotes: 2

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