Pass a Swift class as parameter, and then call a class method out of it
I want to be able to store a class as a variable, so I can call class methods out of it later, something like this:
class SomeGenericItem: NSObject
{
var cellClass: AnyClass
init(cellClass: AnyClass)
{
self.cellClass = cellClass
}
func doSomething(p1: String, p2: String, p3: String)
{
self.cellClass.doSomething(p1, p2: p2, p3: p3)
}
}
class SomeClass: NSObject
{
class func doSomething(p1: String, p2: String, p3: String)
{
...
}
}
I want to be able to say something like:
let someGenericItem = SomeGenericItem(cellClass: SomeClass.self)
someGenericItem.doSomething("One", p2: "Two", p3: "Three")
What I'm trying to figure out is:
1) How would a protocol be defined so I could call class func doSomething?
2) What would the declaration of cellClass need to be?
3) What would the call look like?
Protocols can't define class methods, but static methods are fine. You'll need your wrapper to be generic, and specify a 'where' constraint that guarantees the wrapped type's conformance to your protocol.
Example:
protocol FooProtocol
{
static func bar() -> Void
}
class FooishClass : FooProtocol
{
static func bar() -> Void
{
println( "FooishClass implements FooProtocol" )
}
}
class FooTypeWrapper< T where T: FooProtocol >
{
init( type: T.Type )
{
//no need to store type: it simply is T
}
func doBar() -> Void
{
T.bar()
}
}
Use:
let fooishTypeWrapper = FooTypeWrapper( type: FooishClass.self )
fooishTypeWrapper.doBar()
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