I have these collection of items from firestore:
availability : true
stocks: 100
item: item1
I kind of wanted to decrement the stocks after submitting the form: I have these where() to compare if what the user chose is the same item from the one saved in the firestore.
function incrementCounter(collref) {
collref = firestore
.collection("items")
.doc()
.where(selectedItem, "==", selectedItem);
collref.update({
stocks: firestore.FieldValue.increment(-1),
});
}
This is how I'll submit my form and I've set the incrementCounter() after saving it:
const handleSubmit = (e) => {
e.preventDefault();
try {
const userRef = firestore.collection("users").doc(id);
const ref = userRef.set(
{
....
},
},
{ merge: true }
);
console.log(" saved");
incrementCounter();
} catch (err) {
console.log(err);
}
};
There's no error in submitting the form. However, the incrementCounter() is not working and displays this error:
TypeError: _Firebase_utils__WEBPACK_IMPORTED_MODULE_5__.firestore.collection(...).doc(...).where is not a function
There are few problems here
There should be async-await for both functions
Your fieldValue should start from firebase.firestore.FieldValue not firestoreFieldValue
Also where clause is used for collection, not doc() so remove that as well. Also I don't think this will update the full collection but do check it and see. (The error you are getting is because of this)
I don't know how you are importing firebase in this application and I don't know how you have declared firestore but mostly firestore variable is declared like this
const firestore = firebase.firestore();
In here firestore is a function, not a property
But when you are using it in the FieldValue then it should be like
firebase.firestore.FieldValue.increment(-1),
Notice that firestore here is a property not a function
Your full code should be like this
async function incrementCounter(collref) {
collref = firestore
.collection("items")
.where(selectedItem, "==", selectedItem);
const newRef = await collref.get();
for(let i in newRef.docs){
const doc = newRef.docs[i];
await doc.update({
stocks: firebase.firestore.FieldValue.increment(-1),
});
// You can also batch this
}
}
const handleSubmit = async (e) => {
e.preventDefault();
try {
const userRef = firestore.collection("users").doc(id);
const ref = await userRef.set(
{
....
},
},
{ merge: true }
);
console.log(" saved");
await incrementCounter();
} catch (err) {
console.log(err);
}
};
The where() method exists on a CollectionReference and not a DocumentReference. You also need to get references to those documents first so first get all the matching documents and then update all of them using Promise.all() or Batch Writes:
function incrementCounter() {
// not param required ^^
const collref = firestore
.collection("items")
// .doc() <-- remove this
.where(selectedItem, "==", selectedItem);
// ^^^ ^^^
// doc field field value
// "item" {selectedItemName}
collRef.get().then(async (qSnap) => {
const updates = []
qSnap.docs.forEach((doc) => {
updates.push(doc.ref.update({ stocks: firebase.firestore.FieldValue.increment(-1) }))
})
await Promise.all(updates)
})
}
If you are updating less than 500 documents, consider using batch writes to make sure all updates either fail or pass:
collRef.get().then(async (qSnap) => {
const batch = firestore.batch()
qSnap.docs.forEach((doc) => {
batch.update(doc.ref, { stocks: firebase.firestore.FieldValue.increment(-1) })
})
await batch.commit()
})
You can read more about batch writes in the documentation
I have the following method for displaying 8 latest posts in the app. User will press Show more button and other 8 posts will be displayed. I am trying to add a filter to search by specific fields of the post, and expect the results to be paginated as well. The problem is that I am stuck how to use the query created to get those specific posts and if the user clicks back or cancels filter how to retrieve the latest posts again. I would appreciate if someone could explain how should I get this done.
const getPosts = async () => {
let docs;
let postsReference = firebase.firestore().collection("products").orderBy("createdAt").limit(8);
await postsReference
.get()
.then(documentSnapshot => {
docs = documentSnapshot;
lastVisible = documentSnapshot.docs[documentSnapshot.docs.length - 1];
console.log("last", lastVisible);
});
docs["docs"].forEach(doc => {
postsArray.push(doc.data());
});
postsArray.forEach(function (post) {
createPost(post);
})
}
const paginate = async () => {
let docs;
let postsReference =
firebase.firestore().collection("products").orderBy("createdAt").startAfter(lastVisible).limit(8);
console.log(postsReference);
await postsReference
.get()
.then(documentSnapshot => {
docs = documentSnapshot;
console.log(docs);
lastVisible = documentSnapshot.docs[documentSnapshot.docs.length - 1];
});
docs["docs"].forEach(doc => {
createPost(doc.data());
postsSize++;
});
}
if (showMoreButton != null) {
showMoreButton.addEventListener("click", function () {
paginate();
});
}
applyFilterButton.addEventListener("click", async function () {
....
let filterQuery = firebase
.firestore()
.collection("products")
.where("productType", "==", productTypeOption)
.where("productLocation", "==", productLocationOption);
if (productPriceOption == "high") {
filterQuery = filterQuery.orderBy("price", "desc");
} else {
filterQuery = filterQuery.orderBy("price");
}
await filterQuery
.get()
.then(function (querySnapshot) {
console.log(querySnapshot.docs);
querySnapshot.forEach(function (doc) {
// Does not print to console
console.log("Inside querySnapshot");
console.log(doc.id, " => ", doc.data());
});
});
});
ive had a lot of trouble with firebase arrays, im now using push
I have this
I want to pull all the users down so I do this:
export const pullFromFirebase = () => {
return firebase
.database()
.ref("/users/")
.once("value")
.then(snapshot => {
var users = [];
snapshot.forEach(user => {
users.push(user.val());
});
return users;
});
};
this is fine
however, I now need the unique id -LI7d_i_BmrXktzMoe4p that firebase generated for me so that I can access this record (i.e. for updating and deleting) how do i do this?
You can get the key of the snapshot with the key property: https://firebase.google.com/docs/reference/js/firebase.database.DataSnapshot#key
So you could change your code to this:
export const pullFromFirebase = () => {
return firebase
.database()
.ref("/users/")
.once("value")
.then(snapshot => {
var users = [];
snapshot.forEach(user => {
let userObj = user.val();
userObj.id= user.key;
users.push(userObj);
});
return users;
});
};
You can change this part:
snapshot.forEach(user => {
users.push(user.val());
});
To instead be:
let usersObj = snapshot.val()
for (var user_id in usersObj) {
users.push(Object.assign(usersObj[user_id], {
user_id: user_id,
});
});
That way, instead of each element in the users array only having email, name and username fields, it has user_id as well.
I am trying to write a function that will, after data in a document (within a Firestore 'artists' collection) is changed, will have Google Cloud Functions find all the documents in another collection ('shows') that have a reference field ('artist') that points to the document (within the 'artists' collection) that was just changed.
I can't seem to figure out how to query the reference field. Ive tried everything from using the ID of the artist document, to the path, to the full URL. But I get an error in the Google Cloud Function console:
Error getting documents Error: Cannot encode type ([object Undefined]) to a Firestore Value
Here's a sample of my code:
exports.updateReferenceArtistFields = functions.firestore
.document('artists/{artistId}').onWrite(event => {
var artistRef = event.data.data();
var artistId = artistRef.id;
var ShowsRef = firestore.collection('shows');
var query = ShowsRef.where('artist', '==', artistId).get()
.then(snapshot => {
snapshot.forEach(doc => {
console.log(doc.id, '=>', doc.data());
});
})
.catch(err => {
console.log('Error getting documents', err);
});
});
I would get the artistId from the params directly like this:
var artistId = event.params.artistId;
Example:
exports.updateReferenceArtistFields = functions.firestore
.document('artists/{artistId}').onWrite(event => {
var artistId = event.params.artistId;
var showsRef = firestore.collection('shows');
var query = showsRef.where('artist', '==', artistId).get()
.then(snapshot => {
snapshot.forEach(doc => {
console.log(doc.id, '=>', doc.data());
});
})
.catch(err => {
console.log('Error getting documents', err);
});
});
var jobskill_ref = db.collection('job_skills').where('job_id','==',post.job_id);
jobskill_ref.delete();
Error thrown
jobskill_ref.delete is not a function
You can only delete a document once you have a DocumentReference to it. To get that you must first execute the query, then loop over the QuerySnapshot and finally delete each DocumentSnapshot based on its ref.
var jobskill_query = db.collection('job_skills').where('job_id','==',post.job_id);
jobskill_query.get().then(function(querySnapshot) {
querySnapshot.forEach(function(doc) {
doc.ref.delete();
});
});
I use batched writes for this. For example:
var jobskill_ref = db.collection('job_skills').where('job_id','==',post.job_id);
let batch = firestore.batch();
jobskill_ref
.get()
.then(snapshot => {
snapshot.docs.forEach(doc => {
batch.delete(doc.ref);
});
return batch.commit();
})
ES6 async/await:
const jobskills = await store
.collection('job_skills')
.where('job_id', '==', post.job_id)
.get();
const batch = store.batch();
jobskills.forEach(doc => {
batch.delete(doc.ref);
});
await batch.commit();
//The following code will find and delete the document from firestore
const doc = await this.noteRef.where('userId', '==', userId).get();
doc.forEach(element => {
element.ref.delete();
console.log(`deleted: ${element.id}`);
});
the key part of Frank's answer that fixed my issues was the .ref in doc.ref.delete()
I originally only had doc.delete() which gave a "not a function" error. now my code looks like this and works perfectly:
let fs = firebase.firestore();
let collectionRef = fs.collection(<your collection here>);
collectionRef.where("name", "==", name)
.get()
.then(querySnapshot => {
querySnapshot.forEach((doc) => {
doc.ref.delete().then(() => {
console.log("Document successfully deleted!");
}).catch(function(error) {
console.error("Error removing document: ", error);
});
});
})
.catch(function(error) {
console.log("Error getting documents: ", error);
});
or try this, but you must have the id beforehand
export const deleteDocument = (id) => {
return (dispatch) => {
firebase.firestore()
.collection("contracts")
.doc(id)
.delete()
}
}
You can now do this:
db.collection("cities").doc("DC").delete().then(function() {
console.log("Document successfully deleted!");
}).catch(function(error) {
console.error("Error removing document: ", error);
});
And of course, you can use await/async:
exports.delete = functions.https.onRequest(async (req, res) => {
try {
var jobskill_ref = db.collection('job_skills').where('job_id','==',post.job_id).get();
jobskill_ref.forEach((doc) => {
doc.ref.delete();
});
} catch (error) {
return res.json({
status: 'error', msg: 'Error while deleting', data: error,
});
}
});
I have no idea why you have to get() them and loop on them, then delete() them, while you can prepare one query with where to delete in one step like any SQL statement, but Google decided to do it like that. so, for now, this is the only option.
If you're using Cloud Firestore on the Client side, you can use a Unique key generator package/module like uuid to generate an ID. Then you set the ID of the document to the ID generated from uuid and store a reference to the ID on the object you're storing in Firestore.
For example:
If you wanted to save a person object to Firestore, first, you'll use uuid to generate an ID for the person, before saving like below.
const uuid = require('uuid')
const person = { name: "Adebola Adeniran", age: 19}
const id = uuid() //generates a unique random ID of type string
const personObjWithId = {person, id}
export const sendToFireStore = async (person) => {
await db.collection("people").doc(id).set(personObjWithId);
};
// To delete, get the ID you've stored with the object and call // the following firestore query
export const deleteFromFireStore = async (id) => {
await db.collection("people").doc(id).delete();
};
Hope this helps anyone using firestore on the Client side.
The way I resolved this is by giving each document a uniqueID, querying on that field, getting the documentID of the returned document, and using that in the delete. Like so:
(Swift)
func rejectFriendRequest(request: Request) {
DispatchQueue.global().async {
self.db.collection("requests")
.whereField("uniqueID", isEqualTo: request.uniqueID)
.getDocuments { querySnapshot, error in
if let e = error {
print("There was an error fetching that document: \(e)")
} else {
self.db.collection("requests")
.document(querySnapshot!.documents.first!.documentID)
.delete() { err in
if let e = err {
print("There was an error deleting that document: \(e)")
} else {
print("Document successfully deleted!")
}
}
}
}
}
}
The code could be cleaned up a bit, but this is the solution I came up with. Hope it can help someone in the future!
const firestoreCollection = db.collection('job_skills')
var docIds = (await firestoreCollection.where("folderId", "==", folderId).get()).docs.map((doc => doc.id))
// for single result
await firestoreCollection.doc(docIds[0]).delete()
// for multiple result
await Promise.all(
docIds.map(
async(docId) => await firestoreCollection.doc(docId).delete()
)
)
delete(seccion: string, subseccion: string)
{
const deletlist = this.db.collection('seccionesclass', ref => ref.where('seccion', '==', seccion).where('subseccion', '==' , subseccion))
deletlist.get().subscribe(delitems => delitems.forEach( doc=> doc.ref.delete()));
alert('record erased');
}
The code for Kotlin, including failure listeners (both for the query and for the delete of each document):
fun deleteJobs(jobId: String) {
db.collection("jobs").whereEqualTo("job_id", jobId).get()
.addOnSuccessListener { documentSnapshots ->
for (documentSnapshot in documentSnapshots)
documentSnapshot.reference.delete().addOnFailureListener { e ->
Log.e(TAG, "deleteJobs: failed to delete document ${documentSnapshot.reference.id}", e)
}
}.addOnFailureListener { e ->
Log.e(TAG, "deleteJobs: query failed", e)
}
}