GCD + Firebase Cloudstore - swift

Question

There is a structure that contains structures in the form of an array. In order to fill the core, I must first fill in the internal ones and assign them to the main one. For this, I used the Dispatch Group () and the notices to add and write to the main structure with which I will work. Below is the code I'm using.
But as a result of this method I got a problem. Notification is performed earlier than necessary. What did I do wrong here?
Here is the output from the console:
DONE
[]
FBRecipe(name: "Eel kebab", count: "2", complexity: "3.75", time: "2", category: "Завтрак", type: "САЛАТЫ", about: "Lsvdvskld v\t", ingredient: [], cook: [], photo: [], idOwner: "XT2pgRnAZ8Q5pHH3dHsz5jYUZ613", shared: "0", planing: "0", timestamp: "1536761784.24662")
ingredinet
ingredinet
ingredinet
...
let loadRecipesGroup = DispatchGroup()
let loadItemsQueue = DispatchQueue(label: "ru.bryzgalov.cookbook.loadrecipes", qos: .userInteractive, attributes: [], autoreleaseFrequency: .workItem)
...
func loadRecipeList() {
var recipe = [FBRecipe]()
db.collection("RECIPES").getDocuments() { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for documentRecipe in querySnapshot!.documents {
self.loadItemsQueue.async {
var ingredinet = [FBIngredient]()
var stage = [FBStage]()
var photo = [FBDishPhoto]()
db.collection("RECIPES/\(documentRecipe.documentID)/INGREDIENT").getDocuments(completion: { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for documentIngredient in querySnapshot!.documents {
self.loadItemsQueue.async(group: self.loadRecipesGroup) {
let newIngredinet = FBIngredient(dict: documentIngredient.data() as Dictionary<String,AnyObject>)
ingredinet.append(newIngredinet)
print("ingredinet")
}
}
}
})
db.collection("RECIPES/\(documentRecipe.documentID)/STAGE").getDocuments(completion: { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for documentStage in querySnapshot!.documents {
self.loadItemsQueue.async(group: self.loadRecipesGroup) {
let newStage = FBStage(dict: documentStage.data() as Dictionary<String,AnyObject>)
stage.append(newStage)
}
}
}
})
db.collection("RECIPES/\(documentRecipe.documentID)/PHOTO").getDocuments(completion: { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
for documentDishPhoto in querySnapshot!.documents {
self.loadItemsQueue.async(group: self.loadRecipesGroup) {
let newDishPhoto = FBDishPhoto(dict: documentDishPhoto.data() as Dictionary<String,AnyObject>)
photo.append(newDishPhoto)
}
}
}
})
self.loadRecipesGroup.notify(queue: .main) {
var newRecipe = FBRecipe(dict: documentRecipe.data() as Dictionary<String,AnyObject>)
newRecipe.ingredient = ingredinet
newRecipe.cook = stage
newRecipe.photo = photo
// recipe.append(contentsOf: newRecipe)
print(ingredinet)
print(newRecipe)
}
}
print("DONE")
}
}
}
}

Answer 1

Your done is called immediately because you the calls marked as async executed asynchronously. That means that the program continues execution while those calls are being executed. Once they have results they complete and print what you expect from them. So what happens is your code runs through every statement till the end. And async calls may finish some time after that.