CODEWITHSUNDEEP
iosswiftuitableviewparse-platformuibutton
Akshay Kheveria
Akshay Kheveria

Reputation: 211

How to delete objects from an array stored in Parse column

So , I've made a class called Posts in Parse.com.. This is the image of the class Posts enter image description here

here you can see in objectId column there are objectIds of all the Posts and in the column likes I'm saving the ObjectIds of users who is liking the post.. so basically if a user tap on unlike button the current user's Id should be deleted . this is my current code:

 var query:PFQuery = PFQuery(className: "Posts")
 query.whereKey("objectId", equalTo: postData.objectId!)
 query.whereKey("likes", equalTo: PFUser.currentUser()!.objectId!)
 query.findObjectsInBackgroundWithBlock({ (objects, error) -> Void in

  if let objects = objects {

   for object in objects {

    object.deleteInBackground()

    }

    }
 })

but it deletes the whole row not the user id of current user..

Upvotes: 1

Views: 2198

Answers (3)

Duncan
Duncan

Reputation: 1

I have used your method to remove a users objectID from another users friends list and instead add it to the users blocked friends list, both are in an array on parse. Thanks 

let cell = tableView.cellForRow(at: indexPath) as! cell

let theUsersID = cell.theObjectID.text!

PFUser.current()?.addUniqueObjects(from: [theUsersID], forKey: "friendList")
PFUser.current()?.saveInBackground()

 PFUser.current()?.removeObjects(in: [theUsersID], forKey: "blockFriend")
PFUser.current()?.saveInBackground()


self.usernames.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)

Upvotes: 0

Dovahkiin
Dovahkiin

Reputation: 1239

I believe you are storing userID in your likes array as strings instead of pointers.

In your code, the key "likes" is an array type, but you want to query an objectId which is a string type, clearly parse won't find any column matches this query.

so in your case, you want to remove one of the strings in your likes array(objective c code)

PFQuery *query = [PFQuery queryWithClassName@"Posts"];
[query whereKey:@"objectId" equalTo:postData.objectId];
[query findObjectsInBackgroundWithBlock:^(NSArray *object, NSError *error)
     {
         if (! error)
         {
             //get the post object, index 0 because each post has 1 unique ID
             PFObject *thisObject = [object objectAtIndex:0];
             //get the likes array
             NSMutableArray *array = [[NSMutableArray alloc]initWithArray:thisObject[@"likes"]];
             [array removeObject:/* your user id*/];
             //save the new array
             [thisObject setObject:array forKey:@"likes"];
             [thisObject saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error){
                 if (succeeded)
                 {
                     //success
                 }
             }];
         }
     }];

Upvotes: 0

Björn Kaiser
Björn Kaiser

Reputation: 9912

You can use removeObject:forKey: to only remove this single object from the array. After doing this, call saveInBackground to save the changes back to the server.

See also: https://www.parse.com/docs/ios/guide#objects-arrays

Upvotes: 2

Related Questions