Hi,

I have a Swift code to upload some String and an image to the Kinvey data backend. It compiles successfully and it connects to Kinvey with API calls. I was able to sign up new users and retrieve them back.

But when I try to save data to the data backend, the simulator produces an error:

does not implement 'hostToKinveyPropertyMapping', a required 'KCSPersistable' method for saving the object to the backend'

I have followed the guide and have the function override for hostToKinveyPropertyMapping as instructed. Where is the error? Thanks. The code is below.

Xcode 7.2.1

KinveyKit 1.40.7

 

import UIKit


class UserTableViewController: UITableViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {
   
    var userArray: [String] = []
   
    var activeRecipient = 0
   
    class Image : NSObject {    //all NSObjects in Kinvey implicitly implement KCSPersistable
        var entityId: String! //Kinvey entity _id
        var image: UIImage!
        var senderUsername: String!
        var recipientUsername: String!
    }
   
    override func hostToKinveyPropertyMapping() -> [NSObject : AnyObject]! {
        return [
            "entityId" : KCSEntityKeyId, //the required _id field
            "image" : "image",
            "senderUsername" : "senderUsername",
            "recipientUsername" : "recipientUsername"
        ]
    }

   
   
    func pickImage(sender: AnyObject) {
       
        var image = UIImagePickerController()
        image.delegate = self
        image.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        image.allowsEditing = false
       
        self.presentViewController(image, animated: true, completion: nil)
       
    }
   
    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) {
       
        self.dismissViewControllerAnimated(true, completion: nil)
       
        // Upload to Kinvey
       
        var imageToSend = KCSAppdataStore.storeWithOptions([
            KCSStoreKeyCollectionName : "Images",
            KCSStoreKeyCollectionTemplateClass : Image.self
            ])
       
        let imageSendingData = Image()
        imageSendingData.image = UIImage(data: UIImageJPEGRepresentation(image, 0.5)!)
        imageSendingData.senderUsername = KCSUser.activeUser().username
        imageSendingData.recipientUsername = userArray[activeRecipient]
       
        imageToSend.saveObject(imageSendingData, withCompletionBlock: { (objectsOrNil, errorOrNil) -> Void in
           
            if errorOrNil != nil {
               
                print("Error saving image: \(errorOrNil)")
               
            } else {
               
                print("Save image successful")
               
            }
           
            }, withProgressBlock: nil)
       
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        let userQuery = KCSAppdataStore.storeWithOptions([
            KCSStoreKeyCollectionName : KCSUserCollectionName,
            KCSStoreKeyCollectionTemplateClass : KCSUser.self
            ])  // Kinvey's syntax for declaring the user collection object. 'KCSUserCollectionName' is a reserved constant for the Users collection. KCSUSer is the class.
       
        userQuery.queryWithQuery(KCSQuery(onField: "_id", usingConditional: .KCSNotEqual, forValue: KCSUser.activeUser().kinveyObjectId()), withCompletionBlock: { (users, queryError) -> Void in
           
            for user in users {
                               
                self.userArray.append(user.username)
               
                self.tableView.reloadData()
               
            }
           
           
            }, withProgressBlock: nil)
       
       
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - Table view data source

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 1
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return userArray.count
    }

   
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)

        cell.textLabel?.text = userArray[indexPath.row]

        return cell
    }
   
   
    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
       
        activeRecipient = indexPath.row
       
        pickImage(self)
       
    }

 

 

 

Someone else on this forum has been having a similar problem. I think the problem is that you've nested the Image class inside of your UserTableViewController, and then you've implemented hostToKinveyPropertyMapping as a method of UserTableViewController rather than a method of the Image class.

Image should be it's own class, completely separate from UserTableViewController, and hostToKinveyPropertyMapping should be a method of the Image class.

Hi Edward, Pranav,

Thank you! It does work!

I have another problem with the image not loading and have started a new thread on it.

Thanks for the help.

Sam