Javascript/Firestore: Uncaught (in promise) TypeError: firebase.firestore(…).collection(…).doc(…).collection(…).set is not a function

Question

I'm trying to code a simple form that gets a single user input and the rest are const variables that sets(creates) a new sub-document in an existing document. Currently I am being thrown an error:

Uncaught (in promise) TypeError: firebase.firestore(...).collection(...).doc(...).collection(...).set is not a function

Here is code:

                    <form id="bgForm" method="POST">
                        <div class="wrap-input100 validate-input m-t-25 m-b-35" data-validate="Enter blood glucose">
                            <h5>Update Blood Glucose</h5>
                            <font face="Montserrat">Input Blood Glucose: </font>
                            <input class="input100" type="text" name="inputBloodGlucose" style="font-family:Montserrat;" id="inputBg" required />
                            <button type="submit" class="btn btn-primary" id="updateBG">Update Blood Glucose</button>
                            </form>
                                <script>
                                    (function(){
                                        //Update BG
                                        $('#bgForm').on('submit', async function (e) {
                                            e.preventDefault();
                                            var data = {
                                            bgReading: parseInt($('#inputBg').val()), //get bg int
                                            dateAdded: firebase.firestore.Timestamp.fromDate(new Date()),
                                            isActive: true,
                                            };
                                            firebase.auth().onAuthStateChanged(function(user){
                                                if(user){
                                                    this.userId = user.uid; //stores the userid
                                                }
                                                firebase.firestore().collection("users").doc(userId).collection("glucose").set({
                                                    'bgReading': data.bgReading, 'dateAdded': data.dateAdded, 
                                                    'isActive': data.isActive,
                                                })
                                                .then(function(){
                                                    window.alert("Blood Glucose updated!");
                                                    // window.location.href = "diabetesManagement.php"; 
                                                })
                                                .catch(function(error){
                                                    console.log("Error updating blood glucose", error);
                                                    window.alert("Error updating blood glucose" + error);
                                                });
                                               });
                                            });
                                        })();
                                </script>
                        </div>

I am using

firebase.auth().onAuthStateChanged(function(user){ 
if(user){this.userId = user.uid;}

To get uid of the currently logged in user and then store it in variable. Can I not use this code to perform queries? Because that is the only thing I'm currently leaning on as the reason why an error is being thrown at me.

Peter Haddad Peter Haddad · Accepted Answer · 2020-02-01T12:42:22

Change this:

firebase.firestore().collection("users").doc(userId).collection("glucose").set({
                                                    'bgReading': data.bgReading, 'dateAdded': data.dateAdded, 
                                                    'isActive': data.isActive,
                                                })

Into this:

firebase.firestore().collection("users").doc(userId).collection("glucose").add({
                                                    'bgReading': data.bgReading, 'dateAdded': data.dateAdded, 
                                                    'isActive': data.isActive,
                                                })

There is no set method inside CollectionReference, you need to use add that will add a new document with the data passed.

https://firebase.google.com/docs/reference/js/firebase.firestore.CollectionReference.html#add

Javascript/Firestore: Uncaught (in promise) TypeError: firebase.firestore(…).collection(…).doc(…).collection(…).set is not a function

1 Answers