Extensions add new functionality to an existing class, structure, or enumeration type.
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Questions tagged [swift-extensions]
394 questions
3
votes
0 answers
Is it possible to write an extension for a specific swift Dictionary ... [String : AnyObject]?
I am trying to write an extension for this:
extension [String : AnyObject] {
}
It throws and error. I was also trying to come up with something similar as this:
extension Dictionary: [String : AnyObject] {
}
It also fails.
Is there a solution…
Matej Ukmar
- 2,157
- 22
- 27
3
votes
2 answers
In a Swift extension, get the actual calling object?
Say we are in an instance of SomeClass, consider this simple call
NSNotificationCenter.defaultCenter().addObserver(
self,
selector: #selector(SomeClass.fixer(_:)),
name:"FixerNote",
object:nil)
Say we decide to make an extension to save typing,…
Fattie
- 27,874
- 70
- 431
- 719
3
votes
1 answer
Swift - extending a class only when it conforms to a protocol to use method swizzling
I have a protocol called NakedNavigationBar.
I also have an extension that extends all UIViewControllers that conform to NakedNavigationBar.
The problem is that in the extension I want to add default behaviour so that when the UIViewController…
Adam Carter
- 4,741
- 5
- 42
- 103
3
votes
1 answer
Implement protocol through extension
I'm trying to create a protocol that wraps the process of using the UIImagePickerController to make it more stream-lined in my apps. I essentially have something like this:
public protocol MediaAccessor : UIImagePickerControllerDelegate,…
Kevin DiTraglia
- 25,746
- 19
- 92
- 138
3
votes
6 answers
Convert Integer to Roman Numeral String in Swift
I am looking to take an Integer in Swift and convert it to a Roman Numeral String. Any ideas?
Brian Sachetta
- 3,319
- 2
- 34
- 45
3
votes
1 answer
Default implementation of protocol method with Swift extension
I'm trying to write default behaviour for a delegate method using a Swift extension as below, but it is never called. Does anyone know why or how to do it the right way?
extension NSURLSessionDelegate {
public func URLSession(session:…
Stephan
- 881
- 9
- 24
3
votes
1 answer
Swift convenience initializer extension for SKPhysicsBody
extension SKPhysicsBody {
/// anchorPoint version of init(rectangleOfSize:center:)
convenience init(rectangleOfSize s: CGSize, withAnchorPoint anchorPoint: CGPoint) {
var center = CGPoint()
center.x = (s.width / 2) - (…
Kent Liau
- 915
- 15
- 26
3
votes
1 answer
How to constrain extension to Dictionary with String Key and array of NSManagedObjects as Value
I would like to add an extension on Dictionary that only applies to a dictionary with Strings as Keys and Array of NSManagedObject as Value
Ideally it would look like this:
extension Dictionary where Key : StringLiteralConvertible, Value:…
bogen
- 9,954
- 9
- 50
- 89
3
votes
1 answer
Can I directly access a default static var from the type of a protocol extension?
For Swift fun, I thought I'd build out some alternate reified APIs to GCD. So I threw this in a Playground:
import Foundation
typealias DispatchQueue = dispatch_queue_t
extension DispatchQueue {
static var main:DispatchQueue {
return…
Travis Griggs
- 21,522
- 19
- 91
- 167
3
votes
1 answer
In Swift, is it possible for a Objective-C class' properties to satisfy a Swift @obj protocol computed property requirement?
For instance, I want to extract a Swift protocol from my existing Objective-C class MyFoo. Let's call this protocol FooProtocol.
The situation looks like this:
// In Objective-C
@interface MyFoo
@property(nonatomic, copy) NSString…
fatuhoku
- 4,815
- 3
- 30
- 70
3
votes
1 answer
How to use a protocol with optional class methods in an extension with generic in Swift?
I am trying using extension for an existing class with class method like:
@objc public protocol MyProtocol {
optional class func foo() -> Int
}
And I am using this protocol in an extension with generic like:
extension MyClass {
public func…
Wizard
- 389
- 1
- 2
- 12
3
votes
1 answer
Swift Generics Type Inference Extensions
I am trying to build my understanding of Generics in Swift by creating a Min and Max extension for the Array class (similar to Min and Max Extension methods in C#). There may be a better way to do this, but as I said, it just to help me understand…
fabiossa
- 136
- 1
- 7
3
votes
2 answers
Extending Bool for fun and new control structures in Swift
I'm playing around with Swift extensions, and bumped my head against a strange bug, while trying to extend Bool:
typealias Task = ()->()
extension Bool{
func untilFalse(task: Task){
while !self {println(self); task()}
}
}
var i =…
cfischer
- 24,452
- 37
- 131
- 214
3
votes
0 answers
Swift generics and extension functions override
Having a strange problem with generics on Swift
have a NSManagedObject subclasses hierarchy with extensions:
BaseCloudKitItem<-MyObject
extension BaseCloudKitItem {
func updateDataWithCKRecord(record: CKRecord!, inManagedObjectContext context:…
iiFreeman
- 5,165
- 2
- 29
- 42
3
votes
4 answers
swift type constraints on generic extensions
After some amount of stress, I created the following generic function:
func removeDupes (inout inputCollection : [T] ) -> [T] {
var hashMap = [T : Bool]()
var output = 0
for thing in inputCollection {
if !hashMap[thing] {
…
Gavin
- 6,495
- 3
- 21
- 22