ios - Post UIImage to Instagram using Swift similar to SLComposeViewController

Question

I have an iOS Xcode 7 Swift 2 project I'm working on. The app posts photos to Facebook and Twitter using:

var shareToFacebook: SLComposeViewController = SLComposeViewController(forServiceType: SLServiceTypeFacebook)

and

var shareToTwitter: SLComposeViewController = SLComposeViewController(forServiceType: SLServiceTypeTwitter)

Love how easy and simple for just posting a photo to these two social medias. I didn't need or want the APIs for them.

I want to do something similar and simple for Instagram. What is the best way to do this without having to deal with Instagram API? Or do I have no choice?

My photo data is saved using NSCoding, not in the DocumentDirectory. I looked here for integration but this is for a photo saved in the app directory.

Just something simple like what I already have for Facebook and Twitter.

Answer 1

Updated for Swift 3

import UIKit
import Foundation

class InstagramManager: NSObject, UIDocumentInteractionControllerDelegate {

    private let kInstagramURL = "instagram://app"
    private let kUTI = "com.instagram.exclusivegram"
    private let kfileNameExtension = "instagram.igo"
    private let kAlertViewTitle = "Error"
    private let kAlertViewMessage = "Please install the Instagram application"

    var documentInteractionController = UIDocumentInteractionController()

    // singleton manager
    class var sharedManager: InstagramManager {
        struct Singleton {
            static let instance = InstagramManager()
        }
        return Singleton.instance
    }

    func postImageToInstagramWithCaption(imageInstagram: UIImage, instagramCaption: String, view: UIView) {
        // called to post image with caption to the instagram application

        let instagramURL = NSURL(string: kInstagramURL)

        if UIApplication.shared.canOpenURL(instagramURL! as URL) {

            let jpgPath = (NSTemporaryDirectory() as NSString).appendingPathComponent(kfileNameExtension)

            do {
                try UIImageJPEGRepresentation(imageInstagram, 1.0)?.write(to: URL(fileURLWithPath: jpgPath), options: .atomic)

            } catch {

                print(error)
            }

            let rect = CGRect(x: 0, y: 0, width: 612, height: 612)
            let fileURL = NSURL.fileURL(withPath: jpgPath)
            documentInteractionController.url = fileURL
            documentInteractionController.delegate = self
            documentInteractionController.uti = kUTI

            // adding caption for the image
            documentInteractionController.annotation = ["InstagramCaption": instagramCaption]
            documentInteractionController.presentOpenInMenu(from: rect, in: view, animated: true)
        } else {

            /// display some message about how it didn't work
            /// Like: UIAlertController(title: kAlertViewTitle, message: kAlertViewMessage, preferredStyle: .alert)
        }
    }
}

and then in the ViewController you want to call it in...

InstagramManager.sharedManager.postImageToInstagramWithCaption(imageInstagram: <YOUR IMAGE>, instagramCaption: shareText, view: self.view)

This opens the 'open-in' function if Instagram is installed