Function accepting generic parameters

I have a subclass of NSManagedObject. I'm using a protocol to create a "wrapper" class. In my controller the data can be either: Items or Item1. To be able to use my function I'll have to add the protocol ItemInfo to Items but that means I'll have to add

NSManagedObject

Items

Item1

function

ItemInfo

Items

var items: Items return self


in Items, which seems a bit redundant. I've tried creating a base class but that didn't work.

Items

Is there a better way to let my function accept both Items and Item1 as parameter like using generics?

Items

Item1

NSManagedObject:

NSManagedObject

class Items: NSManagedObject

@NSManaged var name: String
@NSManaged var code: String



Protocol:

Protocol

protocol ItemInfo
var item: Items get


extension ItemInfo

var name : String return item.name
var code : String return item.code



Wrapper:

Wrapper

class Item1: ItemInfo
let item: Items

init(item: Items) self.item = item



function:

function

func handleItem(item: ItemInfo)
print(item.name)
print(item.code)



I could use:

func handleItem<T>(item: T)
if let a = item as? Items
print(a.name)
print(a.code)


if let a = item as? ItemInfo
print(a.name)
print(a.code)




But this doesn't seem the right way ...

1 Answer
1

If I understand correctly what you are trying to achieve (function accepting two kind of items), I would use protocol as type accepted by function, refer the code below

class Items: NSManagedObject, ItemInfo

@NSManaged var name: String
@NSManaged var code: String


class Item1: NSManagedObject, ItemInfo

@NSManaged var name: String
@NSManaged var code: String


protocol ItemInfo
var name: String get set
var code: String get set



and function would look like this

func handle(item: ItemInfo)
print(item.code)
print(item.name)



Item1

ItemInfo

Items

Items

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