How can retrieve {pushId} with firebase cloud functions? - firebase

I am learning firebase cloud functions. I have a function that looks like that:
exports.gameLoopBeing = functions.database.ref('/tables/{pushId}/gamestarted')
.onWrite(event => {
//I want to retrieve the pushID
console.log(event.data.pushID);
});
event.data.pushID clearly doesn't work. How can retrieve the pushID? I looked at the docs and couldn't find anything.
For those who don't know that pushId is. This function listens to every change done inside elements inside /table. For example:
in /table/1 the pushId is 1
in /table/2 the pushId is 2
in /table/N the pushID is N

The wildcards in the ref path are provided in the event params object:
exports.gameLoopBeing = functions.database.ref('/tables/{pushId}/gamestarted')
.onWrite(event => {
//I want to retrieve the pushID
console.log(event.params.pushId);
});

exports.gameLoopBeing = functions.database.ref('/tables/{pushId}/gamestarted')
.onWrite((change, context) => {
//I want to retrieve the pushID
console.log(context.params.pushId);
});

Related

How to create a Firebase Cloud Function for a Document Created on a Collection inside of another Document and Collection

I have a question with CloudFunctions, I need to create a function on Create of a document inside Firestore.
The problem that I have is the way the data is set up:
So I have a Collection called Chat Rooms which gets documents that will vary, and inside each document, you will have some fields and another subcollection, and inside that subcollection already the thing that I need to get on the function.
The problem that I have is that this function should be aware or access with every document created:
Somehting like:
exports.ChatSent = functions.firestore.document('chatrooms/{Variable part}/chats').onCreate((snap, ctx) => { print('do whatever'); return;});
The problem is I don't know how to write that variable part as this function should be executed whenever a new document is written on the Chats collection of each one of the documents inside the Chatroom collection.
Any Ideas?
You should use twice a wildcard when defining the path, as follows:
exports.ChatSent = functions.firestore.document('chatrooms/{chatroomId}/chats/{chatId}').onCreate((snap, ctx) => {
print('do whatever');
return null;
});
If you need to get the wildcards values, do as follows:
exports.ChatSent = functions.firestore.document('chatrooms/{chatroomId}/chats/{chatId}').onCreate((snap, ctx) => {
const chatroomId = ctx.params.chatroomId;
const chatId = ctx.params.chatId;`
print('do whatever');
return null;
});

Combine two arrays on Firebase Cloud Function

I have these two nodes that I need to get on a single http call. I am trying to achieve this by using async/await to get the two nodes and then combine them using concat or forEach. But it seems that even though I am awaiting responses, inside the function they are still promises and not the data itself. This is my basic example:
exports.searchVisit = functions.https.onRequest(async (req, res) => {
const today = new Date(Date.now());
let todayVisits = await admin.database().ref('/visits/').once('value');
let frequentVisits = await admin.database().ref('/frequent_visits/').once('value');
console.log(todayVisits); // Prints an object (I guess it is a promise)
res.status(200).send(todayVisits); // Returns correctly the data on visits collection
});
How could I achieve to return todayVisits and frequentVisits combined? Thanks in advance.
In your code, todayVisits is a DataSnapshot type object. It is not a promise. Logging that DataSnapshot object is not likely to be useful. If you want to see the raw data inside that snapshot, call val() on it to get a JavaScript object with the entire set of data in that snapshot. This is also what you probably want to send to the client (not the entire contents of the DataSnapshot).
The following code, merging the two JavaScript objects obtained with val(), as explained by Doug, should do the trick:
exports.searchVisit = functions.https.onRequest(async (req, res) => {
const today = new Date(Date.now());
let todayVisits = admin.database().ref('/visits/').once('value');
let frequentVisits = admin.database().ref('/frequent_visits/').once('value');
const [todayVisitsSnap, frequentVisitsSnap] = await Promise.all([
todayVisits,
frequentVisits
]);
res.status(200).send({ ...todayVisitsSnap.val(), ...frequentVisitsSnap.val() });
});

Is there any way of knowing if a document has been added to a collection in firebase using firebase functions

Basically the question again:
Suppose there is a collection called 'People'.
Firestore functions can detect changes to a particular document, but is there anyway of knowing when a document(say 'Person1') is added to the collection using firebase functions?
If not, is there any alternate way to get to know when a document is added?
There is a specific function type that only triggers when a document gets created. From the documentation comes this example of how to use it:
exports.createUser = functions.firestore
.document('users/{userId}')
.onCreate((snap, context) => {
// Get an object representing the document
// e.g. {'name': 'Marie', 'age': 66}
const newValue = snap.data();
// access a particular field as you would any JS property
const name = newValue.name;
// perform desired operations ...
});

Firebase query with Vue js

i am new in Vue JS and in Firebase. My target is get all 'eventos' that has same category. I mean, let's i have two eventos, an eventos category "SMIX" and another has "DAM". Now i want to get the eventos has category 'SMIX'
My data structure is here :
created() {
var datos = []
firebase.database().ref('usuarios').on("value", data => {
data.forEach(function(user){
user.child("eventos").orderByChild("categoria").equalTo("SMIX")
.forEach(function(evento){
datos.push(evento.val())
});
});
this.eventos = datos;
});
}[My data Structure][1]
There are several errors and points to be noted in your code:
Firstly, if you receive the error user.child(...).orderByChild is not a function
it is because with data.forEach(function(user) {...}), user is a DataSnapshot (see the forEach() doc), and by calling the child() method on this DataSnapshot you get another DataSnapshot... which does not have a orderByChild() method.
The orderByChild() method is a method of a Reference, so you need to do
user.child(...).ref.orderByChild()
using the ref property of the DataSnapshot
Secondly, you cannot do
user.ref.child("eventos").orderByChild("categoria").equalTo("SMIX")
.forEach()
because you need to use the once() or on() methods to get the data at a database location represented by a Reference.
Thirdly, Since you are going to execute several queries within a loop, you need to use the once() method instead of the on() method. The on() method set a listener that continuously "listens for data changes at a particular location."
Finally, note that you need to use Promise.all() to manage the parallel asynchronous queries to the database.
So, having noted all the points above, the following code will do the trick (to put in created()):
var datos = []
firebase.database().ref('usuarios').once('value')
.then(dataSnapshot => {
var promises = [];
dataSnapshot.forEach(user => {
promises.push(user.ref.child("eventos").orderByChild("categoria").equalTo("SMIX").once('value'));
});
return Promise.all(promises);
})
.then(results => {
//console.log(results);
results.forEach(dataSnapshot => {
dataSnapshot.forEach(evento => {
datos.push(evento.val());
});
});
this.eventos = datos;
});

Meteor Mongo.Cursor returns duplicate rows in Tracker.autorun

I am converting Mongo.Cursor to array using fetch() in Tracker.autorun and assigning it to the songsArray. But each time the underlying database is changed(reactively), I see duplicate values in songsArray
private songsArray:Array<any>;
songsCursor:Mongo.Cursor<any>;
//...Some code here
ngOnInit():any {
//... Some code here
this.songsCursor = Songs.find();
Tracker.autorun(() => {
this.songsArray = [];
this.songsArray = this.songsCursor.fetch();
});
}
Why is it happening and if I assume I am doing it wrong, then what is the correct way to convert cursors to array in Tracker.autorun?
In your constructor you need to do something like this:
$reactive(this).attach($scope);
// Subscribe to collections here:
this.subscribe('songs');
this.helpers({
songs: () => Songs.find()
});
and you'll find songs is an array like you want

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