Get data from a collection with firestore ionic 4 - firebase

I would like to get unique data from doc from a collection with firebase firestore
So i use to get all data:
ngOnInit() {
return this.firestore.collection('users').snapshotChanges()
.subscribe(data => {
console.log(data);
this.utilisateurs = data;
console.log(this.passided);
});
}
and this to get unique id :
this.passided = this.navParams.get('id');
And i tried to do this :
return this.firestore.collection('users').doc(this.passided).snapshotChanges()
but don't work, can you help me please?

snapshotChanges() is a method inside class AngularFirestoreCollection which returns an Observable of data as a DocumentChangeAction.
If you want to manipulate documents, then you can use the following methods:
set(data: T) - Destructively updates a document's data.
update(data: T) - Non-destructively updates a document's data.
delete() - Deletes an entire document. Does not delete any nested collections.
Therefore, this this.firestore.collection('users').doc(this.passided).snapshotChanges() wont work since snapshotChanges() is not a method in the document.ts
For reference:
https://github.com/angular/angularfire2/blob/master/docs/firestore/documents.md#snapshotchanges
https://github.com/angular/angularfire2/blob/master/src/firestore/collection/collection.ts#L97

Related

How to filter field value and send data into the firestore collection?

In the firestore collection named 'doctor' there are different fields including the field 'role'. I want to add the doctors into firestore with a role named doctor. How can I do this? Following is the code that successfully adds data into the database. If you can, tell me the way to add data with a specific field name. Thanks in advance.
service.ts
create_Newdoctor(Record){
return this.firestore.collection('doctors').add(Record);
}
component.ts
CreateRecord(docForm: NgForm){
let Record = {};
Record['fullName']=this.fullName;
Record['email']=this.email;
this.DoctorService.create_Newdoctor(Record).then(res=> {
this.fullName="";
this.email="";
console.log(res);
this.message = "Added";
}).catch(error=>{
console.log(error);
});
}
Notice that Record is a javascript object, and how you create a document in Cloud firestore, is by passing an object with all the filled attributes into the add method like what you did in service.ts, and how you pass in an attribute is via Record[ATTRIBUTE_NAME] = ATTRIBUTE_VALUE
Hence I believe what you need to just to add in the line Record[‘role’] = “doctors” into component.ts

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;
});

Firestore: Getting a subcollection from a DocumentSnapshot

I'm using Firestore for backend for a Flutter project, and the database is nested to have sub-collections under documents.Here's the structure:
I have the data found from the Root collection, and from there I'm trying to get the sub-collection, but I can't figure how to.
There should be a get() method available but I'm not getting any.
Here's the code for the function:
void _getNext(DocumentSnapshot doc) async {
int v = doc.data.length;
String id = doc.documentID;
print('length = $v \t id= $id');
await doc.reference.get().then((val){
val.data.forEach((k, v){
print('k = $k & v = $v');
});
});
await doc.data.forEach((k,v){
print("new k = $k, v = $v");
});
await doc.reference.collection(id).getDocuments().then((val){
val.documents.forEach((e){
print("another k = $e");
});
});
}
And the only response I get from pressing the "Literature" document (from the root collection) is this:
I/flutter (13395): length = 0 id= Literature
There are several sub collections to this document but the returned length is zero. The other blocks of code work fine when I added dummy data to the fields, but that's not needed in my case.
Thank You for your help.
collection() returns a CollectionReference. As you can see from the API docs, neither CollectionReference, nor it superclass Query have a method called get(). I suspect you want to use getDocuments() instead.
There is no get() method for CollectionReference, you need a DocumentReference.
There is nothing wrong with the current situation, you probably want to use getDocuments() since there are no subcollections under your collection, but documents
Notice the alternating pattern of collections and documents. Your collections and documents must always follow this pattern. You cannot reference a collection in a collection or a document in a document.
from: Hierarchical Data

Cloud Functions retrieve List from Firebase Database

I'm triggering a Cloud Function using Http Request.
The issue is to retrieve the entire List of Objects I have, without an event to then loop through them.
The List is under the account/userId Node.
Here is what I use but I get nothing:
return admin.database().ref('/account/' + userId).once('value').then(function (snap) {
let data = snap.val();
}
Without seeing your database structure it is a bit difficult to write an answer and be 100% sure it is a correct one, but the following should do the trick:
return admin.database().ref('/account/' + userId).once('value').then(function (snap)
snap.forEach(function(child) {
const childKey = child.key; // <- here you get the key of each child of the '/account/' + userId node
console.log(childKey);
const childVal = child.val(); // <- and here you get the values of these children as JavaScript objects
console.log(childVal);
});
});
In case this is not exactly what you are looking for, please update you Question with your database structure and the entire code of your Cloud Function.

Firestore: remove sensitive fields on documents

I'm trying to figure it out how to remove a sensitive field on a firestore document. For example, my collection is a group information. The group is protected with a pin code field. Any one wants to join the group has to know the pin code.
In the meantime, I want to let users query what group is available to join. For query part, I don't want return group information with pin code information. Do we have anyway to remove sensitive fields from a document for Firestore for reading event?
Cloud function only supports write event. 1 possible solution is use cloud function on write event, and put pin code in a separate document. Is there a better solution? THanks.
My group schema is:
group: {
name: string,
pinCode: string
}
A user can either access a document, or they can't. There is no property-level access control in Firestore.
So to accomplish what you want, you will need to store the public and private information in separate documents.
You could either create a second document with the private information in the same collection and then secure them using:
match /databases/{database}/documents {
match /groups/{group} {
allow read: if resource.data.visibility != "private"
}
}
Alternatively (and simpler to secure) you could create a separate collection for the private documents.
You can create a Firebase Function that returns only the fields that you need (non sensitive), here an example:
exports.getTopUsers = functions.https.onCall(async (data) => {
const users = [];
return db.collection('users').orderBy('bids').limit(data.limit).get()
.then((querySnapshot) => {
querySnapshot.forEach((user) => {
users.push({
diplayName: user.get('displayName'),
});
});
return {
topUsers: users,
};
})
.catch((err) => {
console.error(err);
});
});
So, you need to create a separate array (that will be returned) and filling it with only the field that you want while iterating your Firestore collection.

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