How to handle shared image in my iOS application? - ios

Question

I am building a social networking app just like instagram. In this app you can take a photo and share inside the app.
I wanted to add my app to "share with..." menu inside the gallery.
Currently I added an app extension, and my app appears on that menu.
However what I want to do is, send the selected image to main application and handle it there. (If user is logged in go to post create screen, if not first login then go create screen.)
How to achieve this goal? I tried launching the app with URL schemes but wasn't able to pass selected image.
Here is code so far:
import UIKit
import Social
import MobileCoreServices
class ShareViewController: SLComposeServiceViewController {
let MAX_SHARE_TEXT_LENGTH = 25
override func isContentValid() -> Bool {
// Do validation of contentText and/or NSExtensionContext attachments here
//Validate text.
if let currentMessage = contentText {
let currentMessageLength = currentMessage.characters.count
charactersRemaining = MAX_SHARE_TEXT_LENGTH - currentMessageLength
if Int(charactersRemaining) < 0 {
return false
}
}
return true
}
override func didSelectPost() {
// This is called after the user selects Post. Do the upload of contentText and/or NSExtensionContext attachments.
// Inform the host that we're done, so it un-blocks its UI. Note: Alternatively you could call super's -didSelectPost, which will similarly complete the extension context.
self.extensionContext!.completeRequestReturningItems([], completionHandler: nil)
}
override func configurationItems() -> [AnyObject]! {
// To add configuration options via table cells at the bottom of the sheet, return an array of SLComposeSheetConfigurationItem here.
print(extensionContext)
return []
}
}