I have this cloud function that creates a new document every time I have a new chat. I am trying to access the values on the messages array, but I got undefined on the console log.
here is my document on firebase:
I am trying to access the messages with lastMessage = data.messages to create a new document with these values on my function:
exports.onConversationCreated = functions.firestore.document('chat/{chatId}')
.onCreate((snapshot, context) => {
let data = snapshot.data();
let chatId = context.params.chatId;
if(data){
let members = data.members;
let lastMessage = data.messages;
for(let index = 0; index < members.length; index++){
let currentUserId = members[index];
let remainingUsersId = members.filter((u) => u != currentUserId);
console.log(lastMessage.message);
remainingUsersId.forEach((m) => {
return admin.firestore().collection('authUsers').doc(m).get().then( (_doc) => {
let userData = _doc.data();
if(userData) {
return admin.firestore().collection("authUsers")
.doc(currentUserId).collection('chat').doc(m).create({
"chatId": chatId,
"image": userData.photoUrl,
"name": userData.displayName,
"unseenCount": 0,
"lastMessage": lastMessage.message,
"timestamp": lastMessage.timestamp,
"type": lastMessage.type
});
}
return null;
}).catch(() => {return null});
})
}
}
return null;
});
I am trying to access the value message which is in the messages array, but I get undefined on the console log, do you guys know how I can access it?
This is because the messages field is an Array with one element, exactly like the members field is an Array with two elements. We can see that from the screenshot of your Firestore database: members has two elements (of type String), indexed with 0 and 1, and messages has one element (of type Map), indexed with 0.
You therefore need to access it as follows:
let lastMessage = data.messages;
//....
console.log(lastMessage[0].message);
It is not clear, from the content of your question, if there is any specific reason for defining the messages field as an Array. Are there any cases when you have several elements? If no, you should probably directly save the messages data as a Map.
In addition, note that you are incorrectly managing the life cycle of your Cloud Function. You should return a Promise when all the asynchronous work is completed. See the doc for more details.
Since you are executing a variable number of calls to Firebase asynchronous methods in a forEach loop, you should use Promise.all().
Related
I'm creating a page object model and one of the properties is all the users from a table. The table has a few columns so I'd like to parse that table and create a user object for each row, then return that set to then be used in tests. So far, this is what that property of my page object looks like:
users: {
get: function() {
let userRecords = [];
var users = element.all(by.repeater('user in users')).each(function(tr, index) {
let user = {
name: tr.element(by.css('td:nth-child(2)')).getText().then(text => {return text;}),
role: tr.element(by.css('td:nth-child(3)')).getText().then(text => {expect(text).toBeTruthy();}),
status: tr.element(by.css('td:nth-child(4)')).getText().then(text => {expect(text).toBeTruthy();}),
//actionsButton: tr.element(by.css('btn btn-default'))
};
userRecords += user;
}).then(userRecords => {return userRecords});
return userRecords;
}
},
Through trial and error I encounter one of two outcomes when just trying to print to screen each element of userRecords:
each element prints as undefined or
userRecords is not defined.
Just to reiterate, I'm simply trying to build an array that holds each user as an object to then be able to iterate / filter on that set in my tests.
Given the approach I'm taking, what's the ideal way to construct this user array and resolve the promises?
Edit: it's worth noting that if I do a console.log() within each of the getText().then() statements, it does print the correct data from the table. So, I do know that it's reading the table correctly.
I'd go with a method that returns json, and would make it async
users: async function() {
let userRecords = [];
var users = element.all(by.repeater('user in users'));
for (let i = 0; i < await users.count(); i++) {
let tr = users.get(i);
let user = {
name: await tr.element(by.css('td:nth-child(2)')).getText(),
role: await tr.element(by.css('td:nth-child(3)')).getText(),
status: await tr.element(by.css('td:nth-child(4)')).getText()
};
userRecords.push()
}
return userRecords;
},
and then use:
console.log(
JSON.stringify(
await constructorName.users()
)
)
should be as simple as that. Note, I didn't test the code, but I did use the approach in my experience. So it may require some minor modifications
In general, try to avoid .then - async/await is easier to use, .each - go with for loop instead. Also userRecords += user; doesn't do what you think it does (though I may be wrong here)
I am deleting a FRTDB node, I want to access deleted data from that node. the functions looks as follow:
exports.events = functions.database.ref('/events/{eventId}').onWrite(async (change, context) => {
const eventId = context.params.eventId
if (!change.after.exists() && change.before.exists()) {
//data removed
return Promise.all([admin.database().ref(`/events/${eventId}/dayofweek`).once('value')]).then(n => {
const pms = []
const days = n[0]
days.forEach(x => {
pms.push(admin.database().ref(`${change.before.val().active ? 'active' : 'inactive'}/${x.key}/${eventId}`).set(null))
})
return Promise.all(pms)
});
else {
return null;
}
})
The probem I am having is that
admin.database().ref(`/events/${eventId}/dayofweek
do not loop the data because it seems data is no longer there so the forEach is not working. How can I get access to this data and get to loop the deleted data?
Of course you won't be able to read data that was just deleted. The function runs after the delete is complete. If you want to get the data that was just deleted, you're supposed to use change.before as described in the documentation:
The Change object has a before property that lets you inspect what was
saved to Realtime Database before the event. The before property
returns a DataSnapshot where all methods (for example, val() and
exists()) refer to the previous value. You can read the new value
again by either using the original DataSnapshot or reading the after
property. This property on any Change is another DataSnapshot
representing the state of the data after the event happened.
The data that was deleted from the database is actually included in the call to your Cloud Function. You can get if from change.before.
exports.events = functions.database.ref('/events/{eventId}').onWrite(async (change, context) => {
const eventId = context.params.eventId
if (!change.after.exists() && change.before.exists()) {
//data removed
days = change.before.val().dayofweek;
...
})
Context:
I 'm doing a cloud function to send pushes to multiple users. I need to recover the info of each user to know some data like, name, country..etc..
Problem:
Actually I recover the list of user Id's and when I got it, then I create an array of promisesto recover all the info:
var usersPromises = []
for (var i = 0; i < usersInRange.length; i++) {
usersPromises[i] = firestore.collection("users").doc(usersInRange[i])
}
Then I recover and send the push using firestore.getAll():
firestore.getAll(...usersPromises).then(results => {
for(snapshot in results){
if(snapshot.exists){
......
var user = snapshot.data()
......
}else{
......
}
}
})
This solution is actually working "fine" almost all the time. But at this moment the Firestore db has some users that do not exist or something is wrong, because the method getAll()stops before finishing all the promises. I know it because no push is sent, and in the console, just say that the method has finished.
Reading in SO and documentation, I saw, that getAll stops if some promise is "broken". (all or nothing)
And here is where I'm lost. How can I "force" or do in another way, to just "jump" this promises that can't be completed?
P.S:
I tried to do with a "for" but It seems to omit some promises:
for (var i = 0; i < usersPromises.length; i++) {
usersPromises[i]
.get()
.then(snapshot => {
if(snapshot.exists){
......
var user = snapshot.data()
......
}else{
......
}
})
}
I think its not a problem of getAll. I have tested like this:
const firestore = new Firestore();
let doc = []
doc[0] = firestore.doc('test/test');
doc[1] = firestore.doc('test/test1');
doc[2] = firestore.doc('test/doc');
firestore.getAll(...doc)
.then(result=> result.forEach(doc => console.log(doc._fieldsProto)))
.catch(err=>console.log(err));
In my database I have 'test/test' and 'test/doc' document, but I do not have 'test/test1' and results look like this:
So we just get undefined on document that is not exist and that's all. I suggest to add catch and see if there is any exception. When I have been writing the test the function was interrupted by typo mistake in inner function.
I hope this will help!
I am using firebase's .onSnapshot to grab the ID of the users currently online, and store each ID to an array. I successfully deployed .onSnapshot to get the ID of the online users, but I return an empty array at the end
var learning_language;
db.collection(ll_profile).doc(user_uid).get().then(function(doc) {
learning_language = doc.data().learning_language;
})
db.collection(ns_status).where("state", "==", "online").onSnapshot(function(snapshot) {
var ns_match = [ ];
snapshot.forEach(function(userSnapshot) {
db.collection("ns_profile").doc(userSnapshot.id).get().then(function(doc) {
spoken_language = doc.data().spoken_language;
if (learning_language == spoken_language) {
ns_match.push(userSnapshot.id);
console.log(ns_match);
}
})
})
return (ns_match);
What I am trying to do is to first define the learning_language retrieved from the collection ll_profile with the current user's ID named user_uid.
Then .onSnapshot listens to another group of users' online state (which automatically updates if an user is online or offline) inside ns_status collection. After, the returned online user from .onSnapshot is checked if the spoken_language field inside their document (named with their corresponding uid) matches with learning_language defined earlier. If it matches, then store the uid into the array of ns_match.
The values inside ns_match are correct. I think .get() executes asynchronously. That is why ns_match is returned empty.
How should I return ns_match at the end with all the values stored properly?
Thanks in advance.
function getMatches() {
return new Promise(resolve => {
db.collection(ll_profile).doc(user_uid).get()
.then(function(doc) {
var learning_language = doc.data().learning_language;
db.collection(ns_status)
.where("state", "==", "online")
.onSnapshot(function(snapshot) {
var ns_match = [];
snapshot.forEach(function(userSnapshot) {
db.collection("ns_profile")
.doc(userSnapshot.id)
.get()
.then(function(doc) {
spoken_language = doc.data().spoken_language;
if (learning_language == spoken_language) {
ns_match.push(userSnapshot.id);
console.log(ns_match);
}
});
});
resolve(ns_match);
});
});
});
}
getMatches().then(ns_matches => console.log(ns_matches));
wrapping in a promise is the correct move. However, remember that snapshot returns metadata about your result. Particularly, snapshot.size. One can use that value to count records, inside the foreach method, or compare the destination array length with the snapshot.size value
I have been doing this for an hour. I simply want to get the number of children in the child "Success" in the database below. The answers in similar stackoverflow questions are not working. I am new in Javascript Programming.
So far I have tried this
var children = firebase.database().ref('Success/').onWrite(event => {
return event.data.ref.parent.once("value", (snapshot) => {
const count = snapshot.numChildren();
console.log(count);
})
})
and also this
var children = firebase.database().ref('Success/').onWrite(event => {
return event.data.ref.parent.once("value", (snapshot) => {
const count = snapshot.numChildren();
console.log(count);
})
})
Where might I be going wrong.
As explained in the doc, you have to use the numChildren() method, as follows:
var ref = firebase.database().ref("Success");
ref.once("value")
.then(function(snapshot) {
console.log(snapshot.numChildren());
});
If you want to use this method in a Cloud Function, you can do as follows:
exports.children = functions.database
.ref('/Success')
.onWrite((change, context) => {
console.log(change.after.numChildren());
return null;
});
Note that:
The new syntax for Cloud Functions version > 1.0 is used, see https://firebase.google.com/docs/functions/beta-v1-diff?authuser=0
You should not forget to return a promise or a value to indicate to the platform that the Cloud Function execution is completed (for more details on this point, you may watch the 3 videos about "JavaScript Promises" from the Firebase video series: https://firebase.google.com/docs/functions/video-series/).
const db = getDatabase(app)
const questionsRef = ref(db, 'questions')
const mathematicalLiteracy = child(questionsRef, 'mathematicalLiteracy')
onValue(mathematicalLiteracy, (snapshot) => {
const data = snapshot.val()
const lenML = data.length - 1
console.log(lenML)
})
This method worked for me. I wanted to get the children's count of the mathematicalLiteracy node in my database tree. If I get its value using .val() it returns an array that contains that node's children and an extra empty item. So, I subtracted that one empty item's count. Finally, I get my needed children's count.