ios - Creating Image Preview using Swift and Parse -

i'm writing social networking application in swift. inside app have feature user can send message timeline image attached. want able retrieve image , preview using uiimageview inside timeline. want image display next user sent image , if user did not post image image preview not appear along message. example of functionally want have way facebook , twitter display images in respective ios apps. in meantime have written following function retrieve images, i'm having trouble matching them proper user. have function posted below link download source code timeline. in advance

func loadimages()

    {         var query = pfquery(classname: "imagesuploaded")         query.orderbydescending("objectid")         query.wherekey("user", equalto:pfuser.currentuser())           query.findobjectsinbackgroundwithblock {             (objects:[anyobject]!,error:nserror!) -> void in             if error == nil {                 let imagesobjects = objects [pfobject]                  object : pfobject in objects [pfobject] {                     let image = object["filename"] pffile                      image.getdatainbackgroundwithblock {                         (imagedata:nsdata!, error:nserror!) -> void in                         if error == nil {                             if let finalimage = uiimage(data: imagedata)                             {                                 let url = image.url                                 println(url)                                 cell.imagedisplay.image = finalimage                                }                         }                      }                 }             }         }         } 

timeline source code

i did this class :

import uikit import parse  class postviewcontroller: uiviewcontroller, uinavigationcontrollerdelegate, uiimagepickercontrollerdelegate {      var photoselected:bool = false     var activityindicator: uiactivityindicatorview = uiactivityindicatorview()      @iboutlet weak var imagetopost: uiimageview!     @iboutlet weak var sharetext: uitextfield!      @ibaction func logout(sender: anyobject) {         pfuser.logout()         self.performseguewithidentifier("logout", sender: "self")     }         @ibaction func chooseimage(sender: anyobject) {         // creation d'une variable image controlleur         var image = uiimagepickercontroller()         dispatch_async(dispatch_get_main_queue()){         image.delegate = self         image.sourcetype = uiimagepickercontrollersourcetype.photolibrary         image.allowsediting = false              self.presentviewcontroller(image, animated: true, completion: nil)}     }      @ibaction func postimage(sender: anyobject) {         var error = ""         if (photoselected == false){             error = "please select image post"         } else if (sharetext.text == "") {             error = "please enter message"         }         if (error != ""){             displayalert("cannot post image", error: error)         } else {              activityindicator = uiactivityindicatorview(frame: cgrectmake(0, 0, 50, 50))             // on positione l'indicateur au centre de l'ecran             activityindicator.center = self.view.center             activityindicator.hideswhenstopped = true             activityindicator.activityindicatorviewstyle = uiactivityindicatorviewstyle.gray             view.addsubview(activityindicator)             activityindicator.startanimating()             uiapplication.sharedapplication().beginignoringinteractionevents()              var post = pfobject(classname: "post")             post["title"] = sharetext.text             post["username"] = pfuser.currentuser().username              post.saveinbackgroundwithblock{(success: bool, error: nserror!) -> void in                  if success == false {                     self.activityindicator.stopanimating()                     uiapplication.sharedapplication().endignoringinteractionevents()                      self.displayalert("could not post image", error: "please try again later")                  } else {                      let imagedata = uiimagepngrepresentation(self.imagetopost.image)                     let imagefile = pffile(name: "image.png", data: imagedata)                      post["imagefile"] = imagefile                     post.saveinbackgroundwithblock{(success: bool, error: nserror!) -> void in                          self.activityindicator.stopanimating()                         uiapplication.sharedapplication().endignoringinteractionevents()                          if success == false {                              self.displayalert("could not post image", error: "please try again later")                         } else {                             self.displayalert(" image posted !", error: "your image has been posted successfully")                             self.photoselected = false                             self.imagetopost.image = uiimage(named: "default-placeholder")                             self.sharetext.text = ""                             println("posted succesfully")                         }                     }                 }             }         }     }      func displayalert(title: string, error: string){         var alert = uialertcontroller(title: title, message: error, preferredstyle: uialertcontrollerstyle.alert)             alert.addaction(uialertaction(title: "ok", style: .default, handler: {action in             }))             self.presentviewcontroller(alert, animated: true, completion: nil)     }      func imagepickercontroller(picker: uiimagepickercontroller, didfinishpickingimage image: uiimage!, editinginfo: [nsobject : anyobject]!) {         println("image selected!")         self.dismissviewcontrolleranimated(true, completion: nil)          imagetopost.image = image          photoselected = true     }      override func viewdidload() {         super.viewdidload()          photoselected = false          imagetopost.image = uiimage(named: "default-placeholder")          self.sharetext.text = ""     }      override func didreceivememorywarning() {         super.didreceivememorywarning()         // dispose of resources can recreated.     }      override func touchesbegan(touches: nsset, withevent event: uievent) {         self.view.endediting(true)     }       func textfiledshouldreturn(textfield: uitextfield!) -> bool{         sharetext.resignfirstresponder()         return true     } } 

edit :

you can add test :

func imagepickercontroller(picker: uiimagepickercontroller, didfinishpickingimage image: uiimage!, editinginfo: [nsobject : anyobject]!) {          self.dismissviewcontrolleranimated(true, completion: nil)         initialisationphoto()          photoutilisateur.image = image          if (photoutilisateur.image != nil){             println("image selected!")             photoselected = true         }     }  func initialisationphoto(){     //initialisation de la photo utilisateur     photoselected = false     photoutilisateur.image = uiimage(named: "placeholder") }