# Storyboardからインスタンスを生成する

Instantiatable.swift

import UIKit

/// Storyboardからインスタンスを生成可能なプロトコル
protocol Instantiatable: class {

    /// Storyboardからインスタンスを生成する
    static func instantiateFromStoryboard() -> Self
}

extension Instantiatable where Self: UIViewController {
    /// instantiateFromStoryboardのデフォルト実装
    static func instantiateFromStoryboard() -> Self {
        let className = String(describing: type(of: self)).replacingOccurrences(of: ".Type", with: "")
        let storyboardName = className.replacingOccurrences(of: "ViewController", with: "")
        let storyboard = UIStoryboard(name: storyboardName, bundle: Bundle(for: Self.self))
        guard let vc = storyboard.instantiateViewController(withIdentifier: className) as? Self else {
            fatalError("Could not instantiate \(className)")
        }
        return vc
    }
}

extension Instantiatable where Self: UITableViewController {
    /// instantiateFromStoryboardのデフォルト実装
    static func instantiateFromStoryboard() -> Self {
        let className = String(describing: type(of: self)).replacingOccurrences(of: ".Type", with: "")
        let storyboardName = className.replacingOccurrences(of: "TableViewController", with: "")
        let storyboard = UIStoryboard(name: storyboardName, bundle: Bundle(for: Self.self))
        guard let vc = storyboard.instantiateViewController(withIdentifier: className) as? Self else {
            fatalError("Could not instantiate \(className)")
        }
        return vc
    }
}