保存API Facebook数据以在不同的ViewController Swift iOS中使用

Question

I'm hitting Facebook's graph to pull basic user info when the user logs in. My question is how do I use swift to save/pull that information in the best way so that it persists across the child viewcontrollers thereafter (basically everything after login). For instance, I want to use the profile pic as a settings button throughout the app after the login screen (not in it) in my login view controller I have this relevant code:

let userImageView: UIImageView = {
    let imageView = UIImageView()

    return imageView
}()

let nameLabel: UILabel = {
    let label = UILabel()

    return label
}()

and then later:

func fetchProfile() {
    let parameters = ["fields": "email, first_name, last_name, picture.type(large)"]
    FBSDKGraphRequest(graphPath: "me", parameters: parameters).startWithCompletionHandler({ (connection, user, requestError) -> Void in

        if requestError != nil {
            print(requestError)
            return
        }

        var _ = user["email"] as? String
        let firstName = user["first_name"] as? String
        let lastName = user["last_name"] as? String

        self.nameLabel.text = "\(firstName!) \(lastName!)"

        var pictureUrl = ""

        if let picture = user["picture"] as? NSDictionary, data = picture["data"] as? NSDictionary, url = data["url"] as? String {
            pictureUrl = url

        }

        let url = NSURL(string: pictureUrl)
        NSURLSession.sharedSession().dataTaskWithURL(url!, completionHandler: { (data, response, error) -> Void in
            if error != nil {
                print(error)
                return
            }

            let image = UIImage(data: data!)
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                self.userImageView.image = image
            })

        }).resume()

    })
}

What do I need to do to access this in my second ViewController? From what I can understand, segues only help if I have a physical attribute in the first viewController to push them from.

Thanks

Answer 1

The best way to save images will be with Documents Directory as Core Data is not optimized for files as large as images. You would want to save the photo in Documents Directory as so......

func saveImageDocumentDirectory(){
        let fileManager = NSFileManager.defaultManager()
        let paths = (NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString).stringByAppendingPathComponent(*** Name of DocDir Image***)
        let image = // *** Your Facebook Image ***
        print(paths)
        let imageData = UIImageJPEGRepresentation(image!, 0.5)
        fileManager.createFileAtPath(paths as String, contents: imageData, attributes: nil)
    }

Then in your viewcontroller(s) create an empty public image var fbImage:UIImage() then create a getImage function and code as follows.....

    func getImage()
{
            let fileManager = NSFileManager.defaultManager()
            let imagePAth = (self.getDirectoryPath() as NSString).stringByAppendingPathComponent(*** Name of Your DocDir Image ***)
            if fileManager.fileExistsAtPath(imagePath){
                self.fbImage.image = UIImage(contentsOfFile: imagePath)
            }else{
                print("No Image Saved")
            }
        }