How to stop observe - swift

Question

I have this code for retrieving data from Firebase database. The code works fine, but it retrieves the same data multiple times.
How do I stop observe so that the data will only be called once
My code
self.eventGalleryImage.child("event")
.child(self.eventName.text!)
.child("EventImages")
.observeSingleEvent(of: .value, with: { (snapshot) in
if let snapshots = snapshot.children.allObjects as? [FIRDataSnapshot] {
for child in snapshots {
if let dict = child.value as? Dictionary<String, Any> {
if let userGallery = dict["Text"] as? String {
self.postsFindGallery.insert(galleryStruct(gallery: userGallery), at: 0)
self.collectionView.reloadData()
}
}
}
}
})

Answer 1

A lesson to be learnt. Do all you can to avoid using for loops when observing data. This is what you'll need to do to get all of the data inside that database path ONCE:
self.eventGalleryImage.child("event")
.child(self.eventName.text!)
.child("EventImages")
.observe(.childAdded, with: { (snapshot) in
guard let dictionary = snapshot.value as? [String: AnyObject] else { return }
if let userGallery = dictionary["Text"] as? String {
self.postsFindGallery.insert(galleryStruct(gallery: userGallery), at: 0)
self.collectionView.reloadData()
}
}, withCancel: nil)
You may also want to try:
DispatchQueue.main.async {
self.collectionView.reloadData()
}