1

Trying to come up with some logic that could help in documenting few resources for firebase. Have looked up few resources in regards to the problem, this question somewhat resembles the issue but not to the extend to solve it. SimillarQuestion . And the avilable doc doesn't mention any logic to implement it either GoogleDoc.

How to get only the keys from a given firebase json tree? As they say a pic tells thousand words. Have got the below mentioned tree for firebase setup. And at mentioned is the required out put where it is displayed to the user in a table view. 

--uniUsers
      |
      |Fruits
      |   |
      |   |Apple:true
      |   |Kiwi:true
      |   |Orange:true
      | 
      |Veggies
          |
          |Carrot:true
          |Onions:true
          |Lettuce:true

Swift Code

 func fetchTotalUsers(){
    let tempUniId = "Fruits"
    let refUniId = Database.database().reference(withPath: "UniUsers/\(tempUniId)")

refUniId.observe(.value, with: { (snapp) in

    print("Value><", snapp.key)
    print("Key><", snapp.value!)
   } 
     }

Swift OutPut:

  Value >< Fruits
  Key >< {
        Apple = 1;
        Kiwi = 1;
        Orange = 1;
        }

Required Output

  Apple
  Kiwi 
  Orange

2 Answers2

1

You can use keys property .

From official documentation here

keys

A collection containing just the keys of the dictionary.

Again from the official documentation:

When iterated over, keys appear in this collection in the same order as they occur in the dictionary’s key-value pairs. Each key in the keys collection has a unique value.

So in your particular case you can do some thing like this:

Since you get dictionary from the firebase server

refUniId.observe(.value, with: { (snapp) in

    print("Value><", snapp.key)
    print("Key><", snapp.value!)

    if let dict = snapp.value as? [String: Any] {

        for k in dict.keys {
             print(k)
        }
    } 
}
3stud1ant3
  • 3,586
  • 2
  • 12
  • 15
  • 1
    This code will indeed only display the keys. But note that it will still **retrieve** all keys *and values*. There is no API in the SDK to retrieve only the keys. See https://stackoverflow.com/questions/37365866/firebase-2016-shallow-query – Frank van Puffelen Nov 30 '17 at 04:42
0

Found by using enumeration we can go step by step but for a newbie the answer selected makes more sense in terms of readability unless the concept of enumeration is known before 

 refUniId.observe(.value, with: { (snapp) in

     print("Count><", snapp.childrenCount)

    let enumeratorRR = snapp.children
    while let rest = enumeratorRR.nextObject() as? DataSnapshot{
    print("GotRequiredFruits",rest.key)
    }
   }