Firebase Query snapshot nil?

Question

I\'m creating a simple chat app to learn Swift and Firebase. I have a query that checks for a chat room\'s messages to load into a tableView. The query returns a snapshot bu

Answer 1

Your dictionary look like :

▿ 1 element
  ▿ 0 : 2 elements
    - key : "-KotqLUUucaRagTRt967"
    ▿ value : 3 elements
      ▿ 0 : 2 elements
        - key : sender
        - value : eGTYRSo81JefgasYLRHUFHUTnEC3
      ▿ 1 : 2 elements
        - key : text
        - value : test
      ▿ 2 : 2 elements
        - key : timestamp
        - value : 1499914135546

But in fact it should look like (If you want to access to dictionary["sender"]) :

▿ 2 elements
  ▿ 0 : 2 elements
    - key : sender
    - value : eGTYRSo81JefgasYLRHUFHUTnEC3
  ▿ 1 : 2 elements
    - key : text
    - value : test
  ▿ 2 : 2 elements
    - key : timestamp
    - value : 1499914135546

First solution :

You need to add .child("-KotqLUUucaRagTRt967") in your query.

OR

Second solution :

You need to do something like that :

query.observe(.childAdded, with: { snapshot in
    for child in snapshot.children {
        guard let value = child.value as? NSDictionary else {
            return
        }

        guard let sender = value["sender"] as? String else {
            return
        }

        // You can user the sender
    }
})

UPDATE :

query.observe(.childAdded, with: { snapshot in
    for child in snapshot.children.allObjects as! [FIRDataSnapshot] {
        if let value = child.value as? [String:Any], let sender = value["sender"] as? String {  
            // You can user the sender
        }
    }
})

NOTE

I replaced observeSingleEvent with observe, as Frank van Puffelen said, it's an uncommon combination for .childAdded.