Firebase Firestore Emulator Returning Data After Deletion? - firebase

I'm working on a React web app and I noticed some weird/unusual behavior when using the Firestore emulator...
I have an onUpdate trigger that is pretty basic:
export const onUsernameUpdateFn = functions.firestore
.document("users/{userId}")
.onUpdate(async (change, context) => {
// Retrieve the current and previous value
const newData = change.after.data();
const previousData = change.before.data();
const operation = "username" in previousData ? "update" : "create";
console.log(
"newData",
newData,
"previousData",
previousData,
"operation",
operation
);
// We'll won't update if the username hasn't changed
if (newData.username === previousData.username) {
console.log("Skipping because username hasn't changed");
return null;
}
// Rest of the things
If I delete all data using the Emulator Suite (http://localhost:4000/firestore) and trigger the above code again, change.before.data() still has data in it...
functions: Beginning execution of "onUsernameUpdate"
> newData {
> createdAt: Timestamp { _seconds: 1652132412, _nanoseconds: 273000000 },
> username: 'differentUsername'
> } previousData {
> createdAt: Timestamp { _seconds: 1652132412, _nanoseconds: 273000000 },
> username: 'originalUsername'
> } operation update
... even though the Firestore UI shows it is empty (correctly).
If I wait some time (20-30 mins or more, haven't measured) after the deletion, then it works as expected and the operation becomes "create" because new and previous values are not equal.
I checked and I am not running multiple emulator instances and the correct project is selected.
Is there some caching in Firestore Emulator? Is it safe to assume that when deployed, this will not be an issue?
Or... is there a better way to skip the update when the username hasn't changed, but make sure it executes when the username property gets written for the first time?
Note: When it works "correctly" after waiting some time, the username property is not present, which is what I expect.

Related

Firebase Functions failing Run the latest Code

I have a firebase function that runs based on a trigger to create a chat room. The function was running for a long time correctly until I updated it to add a new field on the document it is creating. That is archived: false.
After adding the field on the function, it sometimes adds the field when it runs but at times fails to add the field. So I think that firebase at times runs the updated code and sometimes runs the only code when the function is triggered because all other fields are created apart from the archived: false which is created and sometimes not created.
So I fail to understand why this happens yet in the code, the field archived is not dependent on any other variable.
Below is the function.
// firestore trigger to crete a chat room
exports.createChatRooms = functions.firestore.document("/jobs/{id}").onUpdate((change, context) => {
const job = change.after.data();
if (job.status === "Accepted") {
const roomId = context.params.id;
const room = admin.firestore().collection("rooms").doc(roomId);
return room.set({
name: job.title,
jobId: roomId,
createdAt: new Date().getTime(),
agent: job.agent,
archived: false,
user: job.user,
members: [job.user.id, job.agent.id],
});
} else {
return null;
}
});
Kindly help me understand why this is happening.

Decrease response time in Firebase Vue app when liking a post

I have an app with different 'procedures' (think posts or pages), which one can like. Currently the process works: Tap like => run method "likeProcedure" => run dispatch action "likeProcedure" => update UI. It usually happens almost immediately, but sometimes there's a lag that gives this a "non-native" feel. Is there some sort of way that I could return feedback immediately, while stile holding single origin of truth on the firebase database?
Thank you!
Page Code:
<v-icon
v-if="!userProfile.likedProcedures || !userProfile.likedProcedures[procedure.id]"
color="grey lighten-1"
#click="likeProcedure({ id: procedure.id })"
>
mdi-star-outline
</v-icon>
and
computed: {
...mapState(["userProfile"]),
procedures() {
return this.$store.getters.getFilteredProcedures();
},
},
Vuex code:
async likeProcedure({ dispatch }, postId) {
const userId = fb.auth.currentUser.uid;
// update user object
await fb.usersCollection.doc(userId).update({
[`likedProcedures.${postId.id}`]: true,
});
dispatch("fetchUserProfile", { uid: userId });
},
Side note: I'm trying to remove the dispatch("fetchUserProfile") command, but this doesn't work, because then I'm calling dispatch without using it. And I cannot remove dispatch because then the object calling it is empty. And I cannot remove the object, because then the argument ('postId') isn't working. So if anyone knows how to deal with that, that would be extremely helpful.
Thank you :)
So this is the best solution I've come up yet. It kind of destroys the idea of a single source of truth, but at least it provides an immediate UI update:
async likeProcedure({ dispatch, state }, postId) {
console.log("likeProcedure");
const userId = fb.auth.currentUser.uid;
// line below provides immediate update to state and hence to the UI
state.userProfile.likedProcedures[postId.id] = true;
// line below updates Firebase database
await fb.usersCollection.doc(userId).update({
[`likedProcedures.${postId.id}`]: state.userProfile.likedProcedures[
postId.id
],
});
// line below then fetches the updated profile from Firebase and updates
// the profile in state. Kind of useless, but ensures that client and
// Firebase are in-sync
dispatch("fetchUserProfile", { uid: userId });
},
async fetchUserProfile({ commit }, user) {
// fetch user profile
const userProfile = await fb.usersCollection.doc(user.uid).get();
// set user profile in state
commit("setUserProfile", userProfile.data());
// change route to dashboard
if (router.currentRoute.path === "/login") {
router.push("/");
}
},

Firebase Functions onUpdate circular problem

I've this situation with a circular function, having trouble finding a solution.
Have a collection where I have a flag that tells if the data has changed. Also want to log the changes.
export async function landWrite(change, context) {
const newDocument = change.after.exists ? change.after.data() : null
const oldDocument = change.before.data()
const log = {
time: FieldValue.serverTimestamp(),
oldDocument: oldDocument,
newDocument: newDocument
}
const landid = change.after.id
const batch = db.batch()
const updated = newDocument && newDocument.updated === oldDocument.updated
if (!updated) {
const landRef = db.collection('land').doc(landid)
batch.update(landRef, {'updated': true })
}
const logRef = db.collection('land').doc(landid).collection('logs').doc()
batch.set(logRef, log)
return batch.commit()
.then(success => {
return true
})
.catch(error => {
return error
})
}
The problem is that this writes the log twice when the UPDATED flag is false.
But also cannot put the log write in the ELSE statement because the flag can already be UPDATED and a new document update be made so a new log has to be written.
Trigger:
import * as landFunctions from './lands/index'
export const landWrite = functions.firestore
.document('land/{land}')
.onWrite((change, context) => {
return landFunctions.landWrite(change, context)
})
If I understand correctly, the problem here is that the updated flag does not specify which event the update is in response to (as you can't really do this with a boolean). In other words - you may have multiple simultaneous "first-stage" writes to lands, and need a way to disambiguate them.
Here are a few possible options that I would try - from (IMHO) worst to best:
The first option is not very elegant to implement
The first and second options both result in your function being
called twice.
The third option means that your function is only
called once, however you must maintain a separate parallel
document/collection alongside lands.
Option 1
Save some sort of unique identifier in the updated field (e.g. a hash of the stringified JSON event - e.g. hash(JSON.stringify(oldDocument)), or a custom event ID [if you have one]).
Option 2
Try checking the updateMask property of the incoming event, and discard any write events that only affect that property.
Option 3
Store your update status in a different document path/collection (e.g. a landUpdates collection at the same level as your lands collection), and configure your Cloud Function to not trigger on that path. (If you need to, you can always create a second Cloud Function that does trigger on the landUpdates path and add either the same logic or different logic to it.)
Hope this helps!
The main problem here is the inability of differentiating changes that are made by this server function or by a client. Whenever you are in this situation, you should try to explicitly differentiate between them. You can even consider having an extra field like fromServer: true that goes with server's updates and helps the server ignore the related trigger. Having said that, I think I have identified the issue and provided a clear solution below.
This line is misleading:
const updated = newDocument && newDocument.updated === oldDocument.updated
It should be named:
const updateStatusDidNotChange = newDocument && newDocument.updated === oldDocument.updated
I understand that you want the updated flag to be managed by this function, not the client. Let me know if this is not the case.
Therefore, the update field is only changed in this function. Since you want to log only changes made outside of this function, you want to log only when updated did not change.
Here's my attempt at fixing your code in this light:
export async function landWrite(change, context) {
const newDocument = change.after.exists ? change.after.data() : null
const oldDocument = change.before.data()
const updateStatusDidNotChange = newDocument && newDocument.updated === oldDocument.updated
if (!updateStatusDidNotChange) return true; //this was a change made by me, ignore
const batch = db.batch()
if (!oldDocument.updated) {
const landid = change.after.id
const landRef = db.collection('land').doc(landid)
batch.update(landRef, {'updated': true })
}
const log = {
time: FieldValue.serverTimestamp(),
oldDocument: oldDocument,
newDocument: newDocument
}
const logRef = db.collection('land').doc(landid).collection('logs').doc()
batch.set(logRef, log)
return batch.commit()
.then(success => {
return true
})
.catch(error => {
return error
})
}
Edit
I had the exact problem and I had to differentiate changes by the server and the client, and ignore the ones that were from the server. I hope you give my suggestion a try.

Add timestamp in Firestore documents

I'm newbie to Firestore. Firestore docs says...
Important: Unlike "push IDs" in the Firebase Realtime Database, Cloud Firestore auto-generated IDs do not provide any automatic ordering. If you want to be able to order your documents by creation date, you should store a timestamp as a field in the documents.
Reference: https://firebase.google.com/docs/firestore/manage-data/add-data
So do I have to create key name as timestamp in document? Or created is suffice to fulfill above statement from Firestore documentation.
{
"created": 1534183990,
"modified": 1534183990,
"timestamp":1534183990
}
firebase.firestore.FieldValue.serverTimestamp()
Whatever you want to call it is fine afaik. Then you can use orderByChild('created').
I also mostly use firebase.database.ServerValue.TIMESTAMP when setting time
ref.child(key).set({
id: itemId,
content: itemContent,
user: uid,
created: firebase.database.ServerValue.TIMESTAMP
})
Use firestore Timestamp class, firebase.firestore.Timestamp.now().
Since firebase.firestore.FieldValue.serverTimestamp() does not work with add method from firestore. Reference
For Firestore
ref.doc(key).set({
created: firebase.firestore.FieldValue.serverTimestamp()
})
REALTIME SERVER TIMESTAMP USING FIRESTORE
import firebase from "firebase/app";
const someFunctionToUploadProduct = () => {
firebase.firestore().collection("products").add({
name: name,
price : price,
color : color,
weight :weight,
size : size,
createdAt : firebase.firestore.FieldValue.serverTimestamp()
})
.then(function(docRef) {
console.log("Document written with ID: ", docRef.id);
})
.catch(function(error) {
console.error("Error adding document: ", error);
});
}
All you need is to import 'firebase' and then call
firebase.firestore.FieldValue.serverTimestamp() wherever you need it. Be careful with the spelling though, its "serverTimestamp()". In this example it provides the timestamp value to 'createdAt' when uploading to the firestore's product's collection.
That's correct, like most database, Firestore doesn't store creation times. In order to sort objects by time:
Option 1: Create timestamp on client (correctness not guaranteed):
db.collection("messages").doc().set({
....
createdAt: firebase.firestore.Timestamp.now()
})
The big caveat here is that Timestamp.now()uses the local machine time. Therefore, if this is run on a client machine, you have no guarantee the timestamp is accurate. If you're setting this on the server or if guaranteed order isn't so important, it might be fine.
Option 2: Use a timestamp sentinel:
db.collection("messages").doc().set({
....
createdAt: firebase.firestore.FieldValue.serverTimestamp()
})
A timestamp sentinel is a token that tells the firestore server to set the time server side on first write.
If you read the sentinel before it is written (e.g., in a listener) it will be NULL unless you read the document like this:
doc.data({ serverTimestamps: 'estimate' })
Set up your query with something like this:
// quick and dirty way, but uses local machine time
const midnight = new Date(firebase.firestore.Timestamp.now().toDate().setHours(0, 0, 0, 0));
const todaysMessages = firebase
.firestore()
.collection(`users/${user.id}/messages`)
.orderBy('createdAt', 'desc')
.where('createdAt', '>=', midnight);
Note that this query uses the local machine time (Timestamp.now()). If it's really important that your app uses the correct time on the clients, you could utilize this feature of Firebase's Realtime Database:
const serverTimeOffset = (await firebase.database().ref('/.info/serverTimeOffset').once('value')).val();
const midnightServerMilliseconds = new Date(serverTimeOffset + Date.now()).setHours(0, 0, 0, 0);
const midnightServer = new Date(midnightServerMilliseconds);
The documentation isn't suggesting the names of any of your fields. The part you're quoting is just saying two things:
The automatically generated document IDs for Firestore don't have a natural time-based ordering like they did in Realtime Database.
If you want time-based ordering, store a timestamp in the document, and use that to order your queries. (You can call it whatever you want.)
This solution worked for me:
Firestore.instance.collection("collectionName").add({'created': Timestamp.now()});
The result in Cloud Firestore is:
Cloud Firestore Result
Try this one for Swift 4 Timestamp(date: Date())
let docData: [String: Any] = [
"stringExample": "Hello world!",
"booleanExample": true,
"numberExample": 3.14159265,
"dateExample": Timestamp(Date()),
"arrayExample": [5, true, "hello"],
"nullExample": NSNull(),
"objectExample": [
"a": 5,
"b": [
"nested": "foo"
]
]
]
db.collection("data").document("one").setData(docData) { err in
if let err = err {
print("Error writing document: \(err)")
} else {
print("Document successfully written!")
}
}
The way it worked with me, is just taking the timestamp from the snapshot parameter snapshot.updateTime
exports.newUserCreated = functions.firestore.document('users/{userId}').onCreate(async (snapshot, context) => {
console.log('started! v1.7');
const userID = context.params['userId'];
firestore.collection(`users/${userID}/lists`).add({
'created_time': snapshot.updateTime,
'name':'Products I ♥',
}).then(documentReference => {
console.log("initial public list created");
return null;
}).catch(error => {
console.error('Error creating initial list', error);
process.exit(1);
});
});
I am using Firestore to store data that comes from a Raspberry PI with Python. The pipeline is like this:
Raspberry PI (Python using paho-mqtt) -> Google Cloud IoT -> Google Cloud Pub/Sub -> Firebase Functions -> Firestore.
Data in the device is a Python Dictionary. I convert that to JSON.
The problem I had was that paho-mqtt will only send (publish) data as String and one of the fields of my data is timestamp. This timestamp is saved from the device because it accurately says when the measurement was taken regardless on when the data is ultimately stored in the database.
When I send my JSON structure, Firestore will store my field 'timestamp' as String. This is not convenient. So here is the solution.
I do a conversion in the Cloud Function that is triggered by the Pub/Sub to write into Firestore using Moment library to convert.
Note: I am getting the timestamp in python with:
currenttime = datetime.datetime.utcnow()
var moment = require('moment'); // require Moment
function toTimestamp(strDate){
return parsedTime = moment(strDate, "YYYY-MM-DD HH:mm:ss:SS");
}
exports.myFunctionPubSub = functions.pubsub.topic('my-topic-name').onPublish((message, context) => {
let parsedMessage = null;
try {
parsedMessage = message.json;
// Convert timestamp string to timestamp object
parsedMessage.date = toTimestamp(parsedMessage.date);
// Get the Device ID from the message. Useful when you have multiple IoT devices
deviceID = parsedMessage._deviceID;
let addDoc = db.collection('MyDevices')
.doc(deviceID)
.collection('DeviceData')
.add(parsedMessage)
.then ( (ref) => {
console.log('Added document ID: ', ref.id);
return null;
}).catch ( (error) => {
console.error('Failed to write database', error);
return null;
});
} catch (e) {
console.error('PubSub message was not JSON', e);
}
// // Expected return or a warning will be triggered in the Firebase Function logs.
return null;
});
Firestone method does not work. Use Timestamp from java.sql.Timestamp and don't cast to string.. Then firestone formats it properly. For example to mark a now() use:
val timestamp = Timestamp(System.currentTimeMillis())
multiple ways to store time in Firestore
firebaseAdmin.firestore.FieldValue.serverTimestamp() method. The actual timestamp will be computed when the doc is written to the Firestore.
while storing it looks like this:
firebaseAdmin.firestore.Timestamp.now() method.
while storing it looks like this:
For both the methods, next time you fetch data it will return Firestore Timestamp object:
So, you first need to convert it to native js Date object and then you can perform methods on it like toISOString().
export function FStimestampToDate(
timestamp:
| FirebaseFirestore.Timestamp
| FirebaseFirestore.FieldValue
): Date {
return (timestamp as FirebaseFirestore.Timestamp).toDate();
}
Store as unix timestamp Date.now, it'll be stored as number i.e. 1627235565028 but you won't be able to see it as readable Date in firestore db.
To query on this Firestore field, you need to convert the date to timestamp and then query.
Store as new Date().toISOString() i.e. "2021-07-25T17:56:40.373Z" but you won't be able to perform date range query on this.
I prefer the 2nd or 3rd way.
According to the docs, you can "set a field in your document to a server timestamp which tracks when the server receives the update".
Example:
import { updateDoc, serverTimestamp } from "firebase/firestore";
const docRef = doc(db, 'objects', 'some-id');
// Update the timestamp field with the value from the server
const updateTimestamp = await updateDoc(docRef, {
timestamp: serverTimestamp() // this does the trick!
});
Sharing what worked for me after googling for 2 hours, for firebase 9+
import { serverTimestamp } from "firebase/firestore";
export const postData = ({ name, points }: any) => {
const scoresRef = collection(db, "scores");
return addDoc(scoresRef, {
name,
points
date: serverTimestamp(),
});
};
Swift 5.1
...
"dateExample": Timestamp(date: Date()),
...
The newest version from Firestore you should use it as follow
import { doc, setDoc, Timestamp } from "firebase/firestore";
const docData = {
...
dateExample: Timestamp.fromDate(new Date("December 10, 1815"))
};
await setDoc(doc(db, "data", "one"), docData);
or for sever timestamp
import { updateDoc, serverTimestamp } from "firebase/firestore";
const docRef = doc(db, 'objects', 'some-id');
const updateTimestamp = await updateDoc(docRef, {
timestamp: serverTimestamp()
});

Cloud Functions for Firebase: how to get authenticated user in a database trigger [duplicate]

In the example below, is there a way to get the uid of the user who wrote to /messages/{pushId}/original?
exports.makeUppercase = functions.database.ref('/messages/{pushId}/original')
.onWrite(event => {
// Grab the current value of what was written to the Realtime Database.
const original = event.data.val();
console.log('Uppercasing', event.params.pushId, original);
const uppercase = original.toUpperCase();
// You must return a Promise when performing asynchronous tasks inside a Functions such as
// writing to the Firebase Realtime Database.
// Setting an "uppercase" sibling in the Realtime Database returns a Promise.
return event.data.ref.parent.child('uppercase').set(uppercase);
});
UPDATED ANSWER (v1.0.0+):
As noted in #Bery's answer above, version 1.0.0 of the Firebase Functions SDK introduced a new context.auth object which contains the authentication state such as uid. See "New properties for user auth information" for more details.
ORIGINAL ANSWER (pre v1.0.0):
Yes, this is technically possible, although it is not currently documented. The uid is stored with the event.auth object. When a Database Cloud Function is triggered from an admin situation (for example, from the Firebase Console data viewer or from an Admin SDK), the value of event.auth is:
{
"admin": true
}
When a Database Cloud Function is triggered from an unauthenticated reference, the value of event.data is:
{
"admin": false
}
And finally, when a Database Cloud Function is triggered from an authed, but not admin, reference, the format of event.auth is:
{
"admin": false,
"variable": {
"provider": "<PROVIDER>",
"provider_id": "<PROVIDER>",
"user_id": "<UID>",
"token": {
// Decoded auth token claims such as sub, aud, iat, exp, etc.
},
"uid": "<UID>"
}
}
Given the information above, your best bet to get the uid of the user who triggered the event is to do the following:
exports.someFunction = functions.database.ref('/some/path')
.onWrite(event => {
var isAdmin = event.auth.admin;
var uid = event.auth.variable ? event.auth.variable.uid : null;
// ...
});
Just note that in the code above, uid would be null even if isAdmin is true. Your exact code depends on your use case.
WARNING: This is currently undocumented behavior, so I'll give my usual caveat of "undocumented features may be changed at any point in the future without notice and even in non-major releases."
Ever since Firebase functions reached version 1.0, this behavior is no longer undocumented but has sligtly changed. Be sure to read the docs.
Context has been added to cloud functions and you can use it like this
exports.dbWrite = functions.database.ref('/path/with/{id}').onWrite((data, context) => {
const authVar = context.auth; // Auth information for the user.
const authType = context.authType; // Permissions level for the user.
const pathId = context.params.id; // The ID in the Path.
const eventId = context.eventId; // A unique event ID.
const timestamp = context.timestamp; // The timestamp at which the event happened.
const eventType = context.eventType; // The type of the event that triggered this function.
const resource = context.resource; // The resource which triggered the event.
// ...
});

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