refrence to document ID - swift

Question

#IBAction func NextButtonTapped(_ sender: Any) {
//validate the fileds
let Error = validateFields()
if Error != nil {
// there is somthing wrong with the fields show error message
showError(Error!)
}
else {
// create cleaned versions of the data
let Password = PasswordTextField.text!.trimmingCharacters(in:
.whitespacesAndNewlines)
let Email = EmailTextField.text!.trimmingCharacters(in:
.whitespacesAndNewlines)
let Firstname = FirstnameTextField.text!.trimmingCharacters(in:
.whitespacesAndNewlines)
let Lastname = LastnameTextField.text!.trimmingCharacters(in:
.whitespacesAndNewlines)
let Age = AgeTextField.text!.trimmingCharacters(in:
.whitespacesAndNewlines)
// create the user
Auth.auth().createUser(withEmail: Email, password: Password) {
(results, Err) in
// check for errors
if Err != nil {
// there was an error creating the user
self.showError("Error creating user")
}
else {
// user was created succesfully store user info
let db = Firestore.firestore()
db.collection("users").document(results!.user.uid).setData(["first
name":Firstname, "last name":Lastname, "age":Age,
"uid":results!.user.uid]) { (Error) in
if Error != nil {
// show error message
self.showError("error saving user data")
}
}
//transition to the home screen
self.transitionToHome()
}
}
}
}
So basically here I am authenticating the user on firebase. (I made
the document ID = the user ID) then I am entering the users info
into the firebase database into a document where its ID is also
equal to the users ID from when they are authenticated. Now what I
am trying to do is to create or get a reference to the document ID
where some of the users info is already stored like name, last name,
age... so I can later add/merge more info into that same document
the name, last name and age is stored under. This is how I am trying
to merge the info together in a diffrent view controller
db.collection("users").document(*******).setData(["middle
Name":Middlename, "favourite colour":Favouritecolour], merge: true)
{ (Error) in
if Error != nil {
// show error messgae
self.showError("error saving user data")
}
}
Where I put "*******" is where I am supposed to reference the
document ID so I can merge/add this info into the same document as
the other users information where the name, last name and age is
stored.
The code I showed you and asked about earlier on how to get a
document ID from, was code I found on stack overflow where they guy
had a similar problem as mine. He was trying to access something out
of his document but I am just trying to create a reference to the
document ID.
The code form earlier:
func getDocument() {
//get specific document from current user
let docRef =
Firestore.firestore().collection("users").document(Auth.auth().currentUs er?.uid ?? "")
//get data
docRef.getDocument { (document, Error) in
if let document = document, document.exists {
let dataDescription = document.data()
print(dataDescription?["uid"])
} else {
print("Document does not exist")
}
}
}
But I don't know if this code will help me, I just thought it might
because its also accessing the document, thats why I though it might
be my answer to getting the document ID.
So basically my question is what do I need to do wether its adding
to the code I found on this site, or if I have to write my own code,
so I can get a reference to the Document ID where my name, last name
and Age is stored, so I can merge more Info into that document
Thank You Very Much!!!

Answer 1

To print the document ID do something like this:
let docRef = Firestore.firestore().collection("users").document(Auth.auth().currentUser?.uid ?? "")
// Get data
docRef.getDocument { (document, error) in
if let document = document, document.exists {
let dataDescription = document.data()
print(dataDescription?["firstname"])
print(document.documentID)
} else {
print("Document does not exist")
}
}
I highly recommend spending some time in the Firestore documentation, as this is covered in there under getting multiple documents from a collection