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Deserialization

Restoring a settings file#

To restore an editor instance to a previous state, we load the saved instance as serialized settings from our main bundle and wrap it in a Data object. It would, of course, also be possible to make a request and load these settings from a remote URL (compare Open Photo from Remote URL).

The deserialize method of the Deserializer class takes those serialized settings as an argument and returns a result set that exposes a PhotoEditModel instance. This photoEditModel is then used to initialize a new PhotoEditViewController instance alongside some photo to which the edits will be applied.

Note that if you are unsure whether the aspect ratio of the photo that the serialized settings are applied to match the photo that they are derived from, you should pass the photo's dimensions explicitly to the deserializer. This ensures that all dimensions and positions are matched as expected.

File:

import PhotoEditorSDK
import UIKit

class PhotoDeserializationSwift: Example, PhotoEditViewControllerDelegate {
  override func invokeExample() {
    // Create a `Photo` from a URL to an image in the app bundle.
    let photo = Photo(url: Bundle.main.url(forResource: "LA", withExtension: "jpg")!)

    // Create a default `Configuration` with default `AssetCatalog`.
    let configuration = Configuration { builder in
      builder.assetCatalog = AssetCatalog.defaultItems
    }

    // Load the serialized settings from the app bundle. You could also load this from a remote URL for example.
    // See `OpenPhotoFromRemoteURLSwift` to get an idea about the approach to take for this.
    let serializedSettings = try? Data(contentsOf: Bundle.main.url(forResource: "photo_serialization", withExtension: "json")!)

    // Deserialize the serialized settings. If the photo was not serialized along with the edits or you're not sure
    // that the aspect ratio of the current photo and the photo used when creating the serialized settings are identical,
    // you should specify the size of the photo to apply the edits on.
    let deserializationResult = Deserializer.deserialize(data: serializedSettings!, imageDimensions: photo.size, assetCatalog: configuration.assetCatalog)

    // Get the `PhotoEditModel` from the deserialization result.
    let photoEditModel = deserializationResult.model!

    // If the original photo was serialized along with the edits, you could receive it from the deserialization
    // result like this.
    // let photo = Photo.from(photoRepresentation: deserializationResult.photo!)

    // Create and present the photo editor. Make this class the delegate of it to handle export and cancelation.
    // Pass the deserialized `PhotoEditModel` to the editor.
    let photoEditViewController = PhotoEditViewController(photoAsset: photo, configuration: configuration, photoEditModel: photoEditModel)
    photoEditViewController.delegate = self
    photoEditViewController.modalPresentationStyle = .fullScreen
    presentingViewController?.present(photoEditViewController, animated: true, completion: nil)

    // For saving edits, please take a look at `PhotoSerializationSwift`.
  }

  // MARK: - PhotoEditViewControllerDelegate

  func photoEditViewControllerShouldStart(_ photoEditViewController: PhotoEditViewController, task: PhotoEditorTask) -> Bool {
    // Implementing this method is optional. You can perform additional validation and interrupt the process by returning `false`.
    true
  }

  func photoEditViewControllerDidFinish(_ photoEditViewController: PhotoEditViewController, result: PhotoEditorResult) {
    // The image has been exported successfully and is passed as an `Data` object in the `result.output.data`.
    // To create an `UIImage` from the output, use `UIImage(data:)`.
    // See other examples about how to save the resulting image.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func photoEditViewControllerDidFail(_ photoEditViewController: PhotoEditViewController, error: PhotoEditorError) {
    // There was an error generating the photo.
    print(error.localizedDescription)
    // Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func photoEditViewControllerDidCancel(_ photoEditViewController: PhotoEditViewController) {
    // The user tapped on the cancel button within the editor. Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }
}