Array of struct not updating outside the closure

Question

I have an array of struct called displayStruct

struct displayStruct{
let price : String!
let Description : String!
} 

I am reading

Answer 1

You making a asynchronous network request inside closure and compiler doesn't wait for the response, so just Reload Table when get post data. replace the code with below it work works fine for you. All the best.

 func addDataToPostArray(){
        let databaseRef = Database.database().reference()
        databaseRef.child("Post").queryOrderedByKey().observe(.childAdded, with:  {
            snapshot in

            let snapshotValue = snapshot.value as? NSDictionary
            let price = snapshotValue?["price"] as! String
            let description = snapshotValue?["Description"] as! String
            // print(description)
            //  print(price)

            let postArr =  displayStruct(price: price, Description: description)
            self.myPost.append(postArr)
            print(self.myPost.count)
            print(self.myPost)
            self.tableView.reloadData()
       //if i print self.myPost.count i get the correct length

        })
    }

Answer 2

Firebase observe call to the database is asynchronous which means when you are requesting for the value it might not be available as it might be in process of fetching it.

That's why your both of the queries to count returns 0 in viewDidLoad and DataSource delegeate method.

  databaseRef.child("Post").queryOrderedByKey().observe(.childAdded, with:  { // inside closure }

Inside the closure, the code has been already executed and so you have the values.

What you need to do is you need to reload your Datasource in main thread inside the closure.

   databaseRef.child("Post").queryOrderedByKey().observe(.childAdded, with:  { 
       // After adding to array
       DispatchQueue.main.asyc {
           self.tableView.reloadData()
       } 

    }