I have a document, and inside of it there is a collection called relatives. In cloud functions, I have onUpdate() listener for this document. Once something is changed, I want to access that collection inside of my document. Also documents in the collection relatives.
Here is how it looks like:
What I have tried
exports.UpdateLocations = functions.firestore.document("users/{userID}").onUpdate((change, context) => {
const userEmail = change.after.data().email;
const prevLocation = change.before.data().userLocation;
const currentLocation = change.after.data().userLocation;
if (prevLocation === currentLocation) return 0;
if (change.after.data().userType.toString() === "Patient") {
const userLocation = change.after.data().userLocation;
const relatives = change.after.data().relatives;
console.log("User's Current Location: " + userLocation);
console.log("Relatives : "+relatives );
}
return;
});
I want to access relatives and its documents. So I can search and compare field and update them on purpose.
To get a subcollection from a DocumentSnapshot, you must first get a DocumentReference to the document for that snapshot, and then find the CollectionReference under that.
In code:
change.after.ref.collection("relatives")
In here:
change.after gives you the DocumentSnapshot of the modified document.
change.after.ref then gives you the DocumentReference of that document, so its location in the database.
change.after.ref.collection("relatives") then gives you the CollectionReference to the relatives subcollection of the document.
So get data from these subcollections you'll have to actually load that data, it is not already included in the change object that is passed to your function.
So if you want to load all relatives for the user that triggered the function, it'd be something like:
let relativesRef = change.after.ref.collection("relatives");
return relatives.get().then((querySnapshot) => {
querySnapshot.forEach((relativeDoc) => {
console.log(doc.id, doc.data().relativeaccount);
});
});
Related
I have create document like this in react native, I am using rnfirebase library
firestore()
.collection('WaterCanData')
.doc(EntryDate)
.collection('Entries')
.doc(values.customerName)
.set({
CustomerName: values.customerName,
CansOut: values.cansOut,
JarsOut: values.jarsOut,
EmptyCansIn: values.emptyCansIn,
JarsIn: values.jarsIn,
Bottles: values.bottles,
Ice: values.ice
})
.then(() => {
console.log('Entry added!!!!!!!!!');
})
When I try to retrieve EntryDate from WaterCanData Coellection I am not able to fetch it(Document name appears in italic font), So how should I retrive this document which contains a subcollection, Below I have attached my ss of data structure
Data structure
Data structuree
The reason your document appears in italics is because it doesn't currently exist. In Cloud Firestore, subcollections can exist without requiring their parent document to also exist.
Non-existant documents will not appear in queries or snapshots in the client SDKs as stated in the Firebase Console.
This document does not exist, it will not appear in queries or snapshots
If you want to be able to get your entry dates, you need to create the document (which can be empty).
firebase.firestore()
.collection('WaterCanData')
.doc(EntryDate)
.set({}); // an empty document
To create the document at the same time as an entry on it's subcollection, you can use a batched write like so:
const db = firebase.firestore();
const batch = db.batch();
// get references to the relevant locations
const entryDateRef = db
.collection('WaterCanData')
.doc(EntryDate);
const customerRef = entryDateRef
.collection('Entries')
.doc(values.customerName);
// queue the data to write
batch.set(entryDateRef, {});
batch.set(customerRef, {
CustomerName: values.customerName,
CansOut: values.cansOut,
JarsOut: values.jarsOut,
EmptyCansIn: values.emptyCansIn,
JarsIn: values.jarsIn,
Bottles: values.bottles,
Ice: values.ice
})
// make changes to database
batch.commit()
.then(() => {
console.log('Entry added!!!!!!!!!');
});
This will then allow you to list all of the entry dates in your database using something like:
firebase.firestore().collection('WaterCanData')
.get()
.then((querySnapshot) => {
querySnapshot.forEach(doc => {
const entryDate = doc.id;
// const customerEntriesRef = doc.ref.collection('Entries');
console.log('Entry date found: ' + entryDate);
}
});
If (as an example) you wanted to also find how many entries were linked to a given date, you would need to also query each subcollection (here the code gets a little more confusing).
firebase.firestore().collection('WaterCanData')
.get()
.then((querySnapshot) => {
const fetchSizePromises = [];
// for each entry date, get the size of it's "Entries" subcollection
querySnapshot.forEach(doc => {
const entryDate = doc.id;
const customerEntriesRef = doc.ref.collection('Entries');
// if this get() fails, just store the error rather than throw it.
const thisEntrySizePromise = customerEntriesRef.get()
.then(
(entriesQuerySnapshot) => {
return { date: entryDate, size: entriesQuerySnapshot.size }
},
(error) => {
return { date: entryDate, size: -1, error }
}
);
// add this promise to the queue
fetchSizePromises.push(thisEntrySizePromise)
}
// wait for all fetch operations and return their results
return Promise.all(fetchSizePromises);
})
.then((entryInfoResults) => {
// for each entry, log the result
entryInfoResults.forEach((entryInfo) => {
if (entryInfo.error) {
// this entry failed
console.log(`${entryInfo.date} has an unknown number of customers in its Entries subcollection due to an error`, entryInfo.error);
} else {
// got size successfully
console.log(`${entryInfo.date} has ${entryInfo.size} customers in its Entries subcollection`);
}
}
});
Using below code you can console every document id inside waterCanData collection. In your database you have only one document, then it will console your document id. (10042021)
firestore()
.collection('WaterCanData')
.get()
.then((querySnapshot) => {
querySnapshot.forEach((doc) => {
console.log(doc.id)
});
})
I want to add data into the firestore database if the document ID doesn't already exists.
What I've tried so far:
// varuId == the ID that is set to the document when created
var firestore = Firestore.instance;
if (firestore.collection("posts").document().documentID == varuId) {
return AlertDialog(
content: Text("Object already exist"),
actions: <Widget>[
FlatButton(
child: Text("OK"),
onPressed: () {}
)
],
);
} else {
Navigator.of(context).pop();
//Adds data to the function creating the document
crudObj.addData({
'Vara': this.vara,
'Utgångsdatum': this.bastFore,
}, this.varuId).catchError((e) {
print(e);
});
}
The goal is to check all the documents ID in the database and see in any matches with the "varuId" variable. If it matches, the document won't be created. If it doesn't match, It should create a new document
You can use the get() method to get the Snapshot of the document and use the exists property on the snapshot to check whether the document exists or not.
An example:
final snapShot = await FirebaseFirestore.instance
.collection('posts')
.doc(docId) // varuId in your case
.get();
if (snapShot == null || !snapShot.exists) {
// Document with id == varuId doesn't exist.
// You can add data to Firebase Firestore here
}
Use the exists method on the snapshot:
final snapShot = await FirebaseFirestore.instance.collection('posts').doc(varuId).get();
if (snapShot.exists){
// Document already exists
}
else{
// Document doesn't exist
}
To check if document exists in Firestore. Trick is to use .exists method
FirebaseFirestore.instance.doc('collection/$docId').get().then((onValue){
onValue.exists ? // exists : // does not exist ;
});
I know this is a flutter firestore topic but I just want to share my answer.
I am using Vue and I am also doing a validation if the id is already taken on firestore.
This is my solution as of firebase version 9.8.2
const load = async() => {
try {
const listRef = doc(db, 'list', watchLink.value);
let listSnapShot = await getDoc(listRef);
if(listSnapShot._document == null) {
await setDoc(doc(db, 'list', watchLink.value), {
listName: NameofTheList.value
});
throw Error('New list added');
}
else {
throw Error('List already Exist');
}
} catch (error) {
console.log(error.message);
}
}
load();
The watchLink.value is the ID that you want to check
Edit:
if you console.log(listSnapShot), the _document will be set to null if the id does not exist on firestore. See screenshot below
If it does not exist
If ID already exists
QuerySnapshot qs = await Firestore.instance.collection('posts').getDocuments();
qs.documents.forEach((DocumentSnapshot snap) {
snap.documentID == varuId;
});
getDocuments() fetches the documents for this query, you need to use that instead of document() which returns a DocumentReference with the provided path.
Querying firestore is async. You need to await its result, otherwise you will get Future, in this example Future<QuerySnapshot>. Later on, I'm getting DocumentSnapshots from List<DocumentSnapshots> (qs.documents), and for each snapshot, I check their documentID with the varuId.
So the steps are, querying the firestore, await its result, loop over the results. Maybe you can call setState() on a variable like isIdMatched, and then use that in your if-else statement.
Edit: #Doug Stevenson is right, this method is costly, slow and probably eat up the battery because we're fetching all the documents to check documentId. Maybe you can try this:
DocumentReference qs =
Firestore.instance.collection('posts').document(varuId);
DocumentSnapshot snap = await qs.get();
print(snap.data == null ? 'notexists' : 'we have this doc')
The reason I'm doing null check on the data is, even if you put random strings inside document() method, it returns a document reference with that id.
I want to update a document field and I've tried the following code but it doesn't update.
can anyone give me a solution, please?
My Code:
var snapshots = _firestore
.collection('profile')
.document(currentUserID)
.collection('posts')
.snapshots();
await snapshots.forEach((snapshot) async {
List<DocumentSnapshot> documents = snapshot.documents;
for (var document in documents) {
await document.data.update(
'writer',
(name) {
name = this.name;
return name;
},
);
print(document.data['writer']);
//it prints the updated data here but when i look to firebase database
//nothing updates !
}
});
For cases like this, I always recommend following the exact types in the documentation, to see what options are available. For example, a DocumentSnapshot object's data property is a Map<String, dynamic>. To when you call update() on that, you're just updating an in-memory representation of the document, and not actually updating the data in the database.
To update the document in the database, you need to call the DocumentReference.updateData method. And to get from the DocumentSnapshot to a DocumentReference, you call the DocumentSnapshot.reference property.
So something like:
document.reference.updateData(<String, dynamic>{
name: this.name
});
Unrelated to this, your code looks a bit non-idiomatic. I'd recommend using getDocuments instead of snapshots(), as the latter will likely result in an endless loop.
var snapshots = _firestore
.collection('profile')
.document(currentUserID)
.collection('posts')
.getDocuments();
await snapshots.forEach((document) async {
document.reference.updateData(<String, dynamic>{
name: this.name
});
})
The difference here is that getDocuments() reads the data once, and returns it, while snapshots() will start observing the documents, and pass them to us whenever there's a change (including when you update the name).
Update 2021:
Lot of things have changed in the API, for example, Firestore is replaced by FirebaseFirestore, doc is in, etc.
Update a document
var collection = FirebaseFirestore.instance.collection('collection');
collection
.doc('some_id') // <-- Doc ID where data should be updated.
.update({'key' : 'value'}) // <-- Updated data
.then((_) => print('Updated'))
.catchError((error) => print('Update failed: $error'));
Update nested value in a document:
var collection = FirebaseFirestore.instance.collection('collection');
collection
.doc('some_id') // <-- Doc ID where data should be updated.
.update({'key.foo.bar' : 'nested_value'}) // <-- Nested value
.then((_) => print('Updated'))
.catchError((error) => print('Update failed: $error'));
To update some fields of a document without overwriting the entire document, use the following language-specific update() methods:
final washingtonRef = FirebaseFirestore.instance.collection("cites").doc("DC");
washingtonRef.update({"capital": true}).then(
(value) => print("DocumentSnapshot successfully updated!"),
onError: (e) => print("Error updating document $e"));
Server Timestamp
You can set a field in your document to a server timestamp which tracks when the server receives the update.
final docRef = FirebaseFirestore.instance.collection("objects").doc("some-id");
final updates = <String, dynamic>{
"timestamp": FieldValue.serverTimestamp(),
};
docRef.update(updates).then(
(value) => print("DocumentSnapshot successfully updated!"),
onError: (e) => print("Error updating document $e"));
Update fields in nested objects
If your document contains nested objects, you can use "dot notation" to reference nested fields within the document when you call update():
// Assume the document contains:
// {
// name: "Frank",
// favorites: { food: "Pizza", color: "Blue", subject: "recess" }
// age: 12
// }
FirebaseFirestore.instance
.collection("users")
.doc("frank")
.update({"age": 13, "favorites.color": "Red"});
Update elements in an array
If your document contains an array field, you can use arrayUnion() and arrayRemove() to add and remove elements. arrayUnion() adds elements to an array but only elements not already present. arrayRemove() removes all instances of each given element.
final washingtonRef = FirebaseFirestore.instance.collection("cities").doc("DC");
// Atomically add a new region to the "regions" array field.
washingtonRef.update({
"regions": FieldValue.arrayUnion(["greater_virginia"]),
});
// Atomically remove a region from the "regions" array field.
washingtonRef.update({
"regions": FieldValue.arrayRemove(["east_coast"]),
});
Increment a numeric value
You can increment or decrement a numeric field value as shown in the following example. An increment operation increases or decreases the current value of a field by the given amount.
var washingtonRef = FirebaseFirestore.instance.collection('cities').doc('DC');
// Atomically increment the population of the city by 50.
washingtonRef.update(
{"population": FieldValue.increment(50)},
);
I want to add data into the firestore database if the document ID doesn't already exists.
What I've tried so far:
// varuId == the ID that is set to the document when created
var firestore = Firestore.instance;
if (firestore.collection("posts").document().documentID == varuId) {
return AlertDialog(
content: Text("Object already exist"),
actions: <Widget>[
FlatButton(
child: Text("OK"),
onPressed: () {}
)
],
);
} else {
Navigator.of(context).pop();
//Adds data to the function creating the document
crudObj.addData({
'Vara': this.vara,
'Utgångsdatum': this.bastFore,
}, this.varuId).catchError((e) {
print(e);
});
}
The goal is to check all the documents ID in the database and see in any matches with the "varuId" variable. If it matches, the document won't be created. If it doesn't match, It should create a new document
You can use the get() method to get the Snapshot of the document and use the exists property on the snapshot to check whether the document exists or not.
An example:
final snapShot = await FirebaseFirestore.instance
.collection('posts')
.doc(docId) // varuId in your case
.get();
if (snapShot == null || !snapShot.exists) {
// Document with id == varuId doesn't exist.
// You can add data to Firebase Firestore here
}
Use the exists method on the snapshot:
final snapShot = await FirebaseFirestore.instance.collection('posts').doc(varuId).get();
if (snapShot.exists){
// Document already exists
}
else{
// Document doesn't exist
}
To check if document exists in Firestore. Trick is to use .exists method
FirebaseFirestore.instance.doc('collection/$docId').get().then((onValue){
onValue.exists ? // exists : // does not exist ;
});
I know this is a flutter firestore topic but I just want to share my answer.
I am using Vue and I am also doing a validation if the id is already taken on firestore.
This is my solution as of firebase version 9.8.2
const load = async() => {
try {
const listRef = doc(db, 'list', watchLink.value);
let listSnapShot = await getDoc(listRef);
if(listSnapShot._document == null) {
await setDoc(doc(db, 'list', watchLink.value), {
listName: NameofTheList.value
});
throw Error('New list added');
}
else {
throw Error('List already Exist');
}
} catch (error) {
console.log(error.message);
}
}
load();
The watchLink.value is the ID that you want to check
Edit:
if you console.log(listSnapShot), the _document will be set to null if the id does not exist on firestore. See screenshot below
If it does not exist
If ID already exists
QuerySnapshot qs = await Firestore.instance.collection('posts').getDocuments();
qs.documents.forEach((DocumentSnapshot snap) {
snap.documentID == varuId;
});
getDocuments() fetches the documents for this query, you need to use that instead of document() which returns a DocumentReference with the provided path.
Querying firestore is async. You need to await its result, otherwise you will get Future, in this example Future<QuerySnapshot>. Later on, I'm getting DocumentSnapshots from List<DocumentSnapshots> (qs.documents), and for each snapshot, I check their documentID with the varuId.
So the steps are, querying the firestore, await its result, loop over the results. Maybe you can call setState() on a variable like isIdMatched, and then use that in your if-else statement.
Edit: #Doug Stevenson is right, this method is costly, slow and probably eat up the battery because we're fetching all the documents to check documentId. Maybe you can try this:
DocumentReference qs =
Firestore.instance.collection('posts').document(varuId);
DocumentSnapshot snap = await qs.get();
print(snap.data == null ? 'notexists' : 'we have this doc')
The reason I'm doing null check on the data is, even if you put random strings inside document() method, it returns a document reference with that id.
I'm triggering a cloud function with onWrite. Within the onWrite function, I want to do something with the ref ID of the document that was written. How can I grab this? My current code looks something like this, but I don't know how to fill eventID.
exports.syncEvents = functions.firestore
.document('events/{eventID}')
.onWrite((change, context) => {
admin.firestore().collection('users').doc(host).collection('events').doc(eventID).set({
active: true
})
});
change.after is a DocumentSnapshot of the document that changed, after it was written. DocumentSnapshot has a property called id that contains the id of the document. So change.after.id is the document id.
The context object contains the params of the query.
In your example, the context object will look like this:
{
...
params: {
eventID: "whatever-eventId-is"
}
...
}
So you just call get it from the context:
const eventId = context.params.eventId;
Here is more about context:
https://firebase.google.com/docs/reference/functions/cloud_functions.eventcontext