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From Remote URL

PhotoEditor SDK supports loading photo files from a remote URL, this can be a resource hosted by a photo hosting provider such as Vimeo or Wistia or your own servers.

Download the photo file#

Although you can pass a URL directly to the editor, we strongly recommend that you manage to download the remote resource yourself. This allows you more control over where and how the download task is being executed and avoids potential problems around UI locking.

Hence we create a download task and upon successful download instantiate a Data object from the downloadURL which is a local URL pointing to the downloaded file.

To save memory you can also save the file to disk instead of keeping it in memory. For an example of how to do this, see the guide on opening a video from a remote URL.

Initialize the editor#

When the download is finished, we hand off to the main queue to initialize a Photo from the data object and pass it as photoAsset to the PhotoEditViewController to instantiate the photo editor. Setting the current class as the delegate of the PhotoEditViewController allows us to implement export, cancellation and error handling there.

Handling user interaction#

While the download task is executing we disable user interaction. In production, you might want to indicate download progress here.

When the download finished, we can reenable user interaction and dismiss the progress indicator.

File:

import PhotoEditorSDK
import UIKit

class OpenPhotoFromRemoteURLSwift: Example, PhotoEditViewControllerDelegate {
  override func invokeExample() {
    // Although the editor supports opening a remote URL, we highly recommend
    // that you manage the download of the remote resource yourself, since this
    // gives you more control over the whole process. After successfully downloading
    // the file you should pass a `Data` object or a local URL to the downloaded photo
    // to the editor. This example demonstrates how to achieve the former.
    guard let remoteURL = URL(string: "https://img.ly/static/example-assets/LA.jpg") else {
      fatalError("Unable to parse URL.")
    }

    let downloadTask = URLSession.shared.downloadTask(with: remoteURL) { downloadURL, _, error in
      if let error = error {
        fatalError("There was an error downloading the file: \(error)")
      }

      if let downloadURL = downloadURL {
        // File was downloaded successfully. Creating a `Data` object from it.
        // To save memory you can also save the file to disk instead of keeping it in memory.
        // For an example on how to do this, see `OpenVideoFromRemoteURLSwift`.
        let imageData = try? Data(contentsOf: downloadURL)

        // Dispatch to the main queue for any UI work.
        DispatchQueue.main.async {
          // Create a `Photo` from the `Data` object.
          let photo = Photo(data: imageData!)

          // Create a photo editor and pass it the photo. Make this class the delegate of it to handle export and cancelation.
          let photoEditViewController = PhotoEditViewController(photoAsset: photo)
          photoEditViewController.delegate = self

          // Reenable user interaction. In production you would want to dismiss a progress indicator for example.
          self.presentingViewController?.view.isUserInteractionEnabled = true

          // Present the photo editor.
          photoEditViewController.modalPresentationStyle = .fullScreen
          self.presentingViewController?.present(photoEditViewController, animated: true, completion: nil)
        }
      }
    }

    // Disable user interaction while the download is active. In production you would want to show a progress indicator for example.
    presentingViewController?.view.isUserInteractionEnabled = false

    // Start the file download
    downloadTask.resume()
  }

  // 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)
  }
}