Question
Answer and Explanation
Getting the image name using Swift's UIImagePickerController can be a bit tricky because the delegate methods primarily provide the image itself or its URL (if it's from the photo library), but not the original file name directly.
Here's a breakdown of how you can approach this, along with code examples:
1. When the Image is Selected from the Photo Library:
If the image is selected from the photo library, you can use the info[.imageURL] key in the didFinishPickingMediaWithInfo delegate method to get the URL. From there, you might be able to extract the file name, but it’s not guaranteed to be the original name.
Here's an example:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let imageURL = info[.imageURL] as? URL {
let imageName = imageURL.lastPathComponent
print("Image Name: \(imageName)")
}
picker.dismiss(animated: true, completion: nil)
}
Important Considerations:
- The .imageURL key might not always be available or provide the original file name. The URL could be a reference to a database record, or a temporary URL generated by the system.
- The system may modify the image (e.g., rotate it to correct orientation), so even if you get a file name, it might not perfectly match the original.
2. When the Image is Newly Captured with the Camera:
If the image is newly captured with the camera using UIImagePickerController, you don't have a file name initially. You would need to save the image to a file and then assign a name to it.
Here's a simplified approach:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let pickedImage = info[.originalImage] as? UIImage {
// Generate a unique file name.
let imageName = UUID().uuidString + ".jpg" // Or ".png"
// Get the documents directory URL
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
// Create the file URL
let fileURL = documentsDirectory.appendingPathComponent(imageName)
// Convert the image to data (JPEG or PNG)
if let data = pickedImage.jpegData(compressionQuality: 0.8) { // or pickedImage.pngData()
do {
// Write the data to the file URL
try data.write(to: fileURL)
print("Image saved with name: \(imageName)")
} catch {
print("Error saving image: \(error)")
}
}
}
picker.dismiss(animated: true, completion: nil)
}
Explanation:
1. Get the Image: The code first retrieves the image from the info dictionary using the .originalImage key.
2. Generate a Unique File Name: A UUID (Universally Unique Identifier) is used to create a unique name for the image file. You can also add a file extension like .jpg or .png.
3. Get the Documents Directory: This obtains the URL of the user's documents directory, where you can save the image.
4. Create the File URL: This combines the documents directory URL with the image name to create the full file path where the image will be saved.
5. Convert Image to Data: The image is converted into Data, either as JPEG or PNG. The compressionQuality parameter for JPEG ranges from 0.0 (highest compression, lowest quality) to 1.0 (lowest compression, highest quality).
6. Write Data to File: The data.write(to: fileURL) method attempts to write the image data to the specified file path. A do-catch block handles potential errors during the write operation.
7. Print the Image Name: If the image is saved successfully, the code prints the generated image name to the console.
Important Considerations:
- Error Handling: Always include robust error handling when dealing with file system operations. The do-catch block is essential.
- Permissions: Ensure your app has the necessary permissions to access the photo library and save files to the documents directory. This usually involves adding keys to your app's Info.plist file (e.g., NSPhotoLibraryUsageDescription, NSCameraUsageDescription).
- File Format: Choose the appropriate file format (JPEG or PNG) based on your needs. JPEG is generally better for photographs due to its compression, while PNG is better for images with sharp lines and text.
- Asynchronous Saving: For larger images, saving on the main thread can block the UI. Consider performing the save operation on a background thread using DispatchQueue.global().async { ... }.
- Cleanup: Remember to handle cleanup, such as removing temporary files if necessary.
3. Alternatives for Choosing Images:
Consider using PHPickerViewController (available from iOS 14 and later) from the Photos framework. It provides a more modern and privacy-conscious way to select photos and videos. It doesn't provide direct file paths but returns PHPickerResult objects, which you can use to access the image data.
In Summary, while UIImagePickerController doesn't directly provide the original file name, you can attempt to extract it from the URL if the image is from the photo library, or you can assign a name when saving a newly captured image.