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[Swift] To retrieve classes at runtime which conforms to a protocol or to retrieve subclasses of a given class
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// | |
// Runtime.swift | |
// Swift Runtime [Swift 4] | |
// | |
// The MIT License (MIT) | |
// | |
// Copyright (c) 2016 Electricwoods LLC, Kaz Yoshikawa. | |
// | |
// Permission is hereby granted, free of charge, to any person obtaining a copy | |
// of this software and associated documentation files (the "Software"), to deal | |
// in the Software without restriction, including without limitation the rights | |
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
// copies of the Software, and to permit persons to whom the Software is | |
// furnished to do so, subject to the following conditions: | |
// | |
// The above copyright notice and this permission notice shall be included in | |
// all copies or substantial portions of the Software. | |
// | |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
// THE SOFTWARE. | |
// | |
// Usage: | |
// | |
// // find classes conform to objc protocol | |
// @objc protocol ThatProtocol {} | |
// class ThatClass1: NSObject, ThatProtocol {} | |
// Runtime.classes(conformToProtocol: ThatProtocol.Type.self) // [ThatClass1] | |
// | |
// // find classes conform to swift protocol | |
// protocol ThisProtocol {} | |
// class ThisClass1: ThisProtool {} | |
// class ThisClass2: ThisClass1 {} | |
// struct ThisStruct: ThisProtocol {} | |
// Runtime.classes(conformTo: ThisProtocol.Type.self) // [ThisClass1, ThisClass2] | |
// | |
// // find subclasses of a specified class | |
// class HerClass1 {} | |
// class HerClass2: HerClass1 {} | |
// class HerClass3: HerClass2 {} | |
// Runtime.subclasses(of: HerClass1.self) // [HerClass1, HerClass2, HerClass3] | |
// Runtime.subclasses(of: HerClass2.self) // [HerClass2, HerClass3] | |
// Runtime.subclasses(of: HerClass3.self) // [HerClass3] | |
// | |
// // instanciate an object or a struct that provides initializers from given string | |
// protocol Shape { | |
// init() | |
// } | |
// class Circle: Shape { | |
// required init() {} | |
// } | |
// class Rectangle: Shape { | |
// required init() {} | |
// } | |
// func instanciate(name: String) -> Shape? { | |
// if let aClass = Runtime.classes(conformTo: Shape.Type.self) | |
// .filter({ String(describing: $0) == name }) | |
// .first as? Shape.Type { | |
// return aClass.init() | |
// } | |
// return nil | |
// } | |
// | |
// | |
// Caution: | |
// You may not be able to use `as?` operator to filter AnyClass from `allClasses()`. | |
// Because there are some classes such as `CNZombie` which causees crash with `as?` | |
// operator. | |
// | |
// for type in Runtime.allClasses() { | |
// if let type = type as? NSView.self { // could cause crash | |
// } | |
// } | |
// | |
import Foundation | |
class Runtime { | |
public static func allClasses() -> [AnyClass] { | |
let numberOfClasses = Int(objc_getClassList(nil, 0)) | |
if numberOfClasses > 0 { | |
let classesPtr = UnsafeMutablePointer<AnyClass>.allocate(capacity: numberOfClasses) | |
let autoreleasingClasses = AutoreleasingUnsafeMutablePointer<AnyClass>(classesPtr) | |
let count = objc_getClassList(autoreleasingClasses, Int32(numberOfClasses)) | |
assert(numberOfClasses == count) | |
defer { classesPtr.deallocate() } | |
let classes = (0 ..< numberOfClasses).map { classesPtr[$0] } | |
return classes | |
} | |
return [] | |
} | |
public static func subclasses(of `class`: AnyClass) -> [AnyClass] { | |
return self.allClasses().filter { | |
var ancestor: AnyClass? = $0 | |
while let type = ancestor { | |
if ObjectIdentifier(type) == ObjectIdentifier(`class`) { return true } | |
ancestor = class_getSuperclass(type) | |
} | |
return false | |
} | |
} | |
public static func classes(conformToProtocol `protocol`: Protocol) -> [AnyClass] { | |
let classes = self.allClasses().filter { aClass in | |
var subject: AnyClass? = aClass | |
while let aClass = subject { | |
if class_conformsToProtocol(aClass, `protocol`) { print(String(describing: aClass)); return true } | |
subject = class_getSuperclass(aClass) | |
} | |
return false | |
} | |
return classes | |
} | |
public static func classes<T>(conformTo: T.Type) -> [AnyClass] { | |
return self.allClasses().filter { $0 is T } | |
} | |
} |
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