ShareViewController.swift

override func didSelectPost() {
	guard let extensionItem = extensionContext?.inputItems.first as? NSExtensionItem else { return }
	guard let itemProvider = extensionItem.attachments?.first as? NSItemProvider else { return }
	let imageContentType = kUTTypeImage as String
	if itemProvider.hasItemConformingToTypeIdentifier(imageContentType) {
		itemProvider.loadItem(forTypeIdentifier: imageContentType, options: nil) { [unowned self] (url, error) in
			if error == nil, let url = url as? URL {
				do {
					let imageData = try Data(contentsOf: url)
					self.saveImageToAppGroupFolder(imageData: imageData)
				} catch {
					// figure out what's wrong
				}
			} else {
				// figure out what's wrong
			}
			self.extensionContext?.completeRequest(returningItems: [], completionHandler: nil)
		}
	} else {
		extensionContext?.completeRequest(returningItems: [], completionHandler: nil)
	}
}