Misen is a script to support using Xcode Asset Catalog in Swift.


Misen scans sub-directories in the specified Asset Catalog and creates a UIImage extension file which has the following features.

  • Application-specific enum which is constructed from Asset Catalog names and UIImage object can be instantiated directly from it.
  • UIImage non-failable initializer whose argument is an enum value above.


  • Change file permissions first.

chmod +x misen.swift
  • Run the script.

./misen.swift -path PATH/TO/XCASSETS -exportPath PATH/TO/GENERATED_FILE -enumName ENUM_NAME
  • -path is a path of the asset catalog.
  • -exportPath is an output UIImage extension file path.
  • -enumName is an enum name to be generated. This is optional and ImageAsset is used as default when this parameter is not specified.


Misen generates the file below from the asset catalog with 3 image sets below.
For reference, see the script of the sample project.

import UIKit

// MARK: - UIImage extension
extension UIImage {
    convenience init!(assetName: ImageAsset) {
        self.init(named: assetName.rawValue)

// MARK: - ImageAsset
enum ImageAsset: String {
    case camera = "camera"
    case contact = "contact"
    case home = "home"

    var image: UIImage {
        return UIImage(named: self.rawValue)!
  • In your code, you can instantiate images in Asset Catalog as follows.

class ViewController: UIViewController {

    @IBOutlet weak var cameraImageView: UIImageView! {
        didSet {
            // Instantiate UIImage directly from ImageAsset enum
            cameraImageView.image = ImageAsset.camera.image

    @IBOutlet weak var contactImageView: UIImageView! {
        didSet {
            contactImageView.image = ImageAsset.contact.image

    @IBOutlet weak var homeImageView: UIImageView! {
        didSet {
            // Instantiate UIImage with UIImage extension
            homeImageView.image = UIImage(assetName: .home)


  • Xcode 8.0
  • Swift 3.0

Release Notes

See Releases.


Misen is released under the MIT license. See LICENSE for details.