How to fix error when looking for child in firebase database (Swift)? - swift

Question

I am trying to save items to a Firebase database under a child taken from a text field. I haven't got to that yet though, I am still trying to work out how to check if a value already exists. Here is my code...
#objc func submitNote() {
print("Attempting to save or update note")
//Check if file exists
if name != nil && text != nil {
//Access database
var ref: DatabaseReference!
ref = Database.database().reference()
ref.child("lists").observeSingleEvent(of: .value, with: { (snapshot) in
if snapshot.hasChild(self.name!){
print("true")
//Update
return
} else {
print("false")
//Create
self.uploadNew()
}
})
return
} else {
print("Error")
return
}
}
It has to be an #objc function as it is run using #selector in a menu bar. As you can see it checks to make sure the text fields aren't empty. Here are the variables...
public var name: String?
public var text: String?
Which are set inside separate functions...
name = titleText.text
text = textView.text
The reason I have set the variables this way is because I am creating the view programically and both individual text views/fields are set inside functions so I don't think I can access them from the submitNote function. Anyway the error I'm getting it this...
*** Terminating app due to uncaught exception 'InvalidPathValidation', reason: '(hasChild:) Must be a non-empty string and not contain '.' '#' '$' '[' or ']''
I have checked and triple checked but there aren't any of those values in the text fields and even though the if statement is meant to stop the app continuing unless they are not equal to nil I tried with text in the fields but no matter what if I press the button to run this function I get the same error. Does anyone know how to fix it?

Answer 1

You only check if name is not null but not if it is empty ("")
if let value = self.name, !value.isEmpty...

Answer 2

Your Firebase structure was not included in the question so I'll make one up for you
lists
Leroy: true
Billy: true
James: true
now some code to see if a name exists in the lists node. We're using snapshot.exists to see if any data was returned in the snapshot.
func doesNameExistInLists(name: String) {
let ref = self.ref.child("lists").child(name)
ref.observeSingleEvent(of: .value, with: { snapshot in
if snapshot.exists() {
print("found it")
} else {
print("name not found")
}
})
}
then when it's called, here are the results
self.doesNameExistInLists(name: "Billy")
console: found it
self.doesNameExistInLists(name: "aaaa")
console: name not found