I have the following structure on my Firebase database:
I would like to search for a user by name, last name or email but as I don't have the user key in the level above I don't know how I can achieve this. I'm doing and administrator session so it wouldn't have access to the user key.
I have tried:
let usersRef = firebase.database().ref('users');
usersRef.orderByValue().on("value", function(snapshot) {
console.log(snapshot.val());
snapshot.forEach(function(data) {
console.log(data.key);
});
});
But it brings all the users on the database. Any ideas?
You can use equalTo() to find any child by value. In your case by name:
ref.child('users').orderByChild('name').equalTo('John Doe').on("value", function(snapshot) {
console.log(snapshot.val());
snapshot.forEach(function(data) {
console.log(data.key);
});
});
The purpose of orderByChild() is to define the field you want to filter/search for. equalTo() can get an string, int and boolean value.
Also can be used with auto generated keys (pushKey) too.
You can find all the documentation here
A warning to avoid unpleasant surprises: when you use orderByChild and equalTo do not forget to add an index on your data (here's the doc)
If you don't all the nods will be downloaded and filtered client side which can become very expensive if your database grows.
Related
I'm trying to implement a normal authentication system in my app, but I'd like to create a new field for each user that is the "uniqueName" so users can search and add each other in their friends list. I was thinking of adding a textField in the signup form for the uniqueName and updating my User class adding a new String in this way:
class User {
String email;
String name;
String uniqueName;
String userID;
String profilePictureURL;
String appIdentifier;
...
}
Now, since I have this method for the email&password signup:
static firebaseSignUpWithEmailAndPassword(String emailAddress,String password,File? image,String name,) async {
try {
auth.UserCredential result = await auth.FirebaseAuth.instance
.createUserWithEmailAndPassword(
email: emailAddress, password: password);
String profilePicUrl = '';
if (image != null) {
await updateProgress('Uploading image, Please wait...');
profilePicUrl =
await uploadUserImageToFireStorage(image, result.user?.uid ?? '');
}
User user = User(
email: emailAddress,
name: name,
userID: result.user?.uid ?? '',
profilePictureURL: profilePicUrl);
String? errorMessage = await firebaseCreateNewUser(user);
if (errorMessage == null) {
return user;
} else {
return 'Couldn\'t sign up for firebase, Please try again.';
}
}
how do I have to modify it in order to add this new field in the registration? Since I have to check that the uniqueName insert by the user is effectively unique before creating a new user in the database, what can I do?
Furthermore, I think that it would be cool if this check is made concurrently to the filling of the form, how can I do it? (this is not necessary)
Thanks everyone for the answers
You have to save your users in a collection, then check if uniqueName already exists in the collection. If it exists, return error.
Then when a new user account is created, save the uniqueName.
// this function checks if uniqueName already exists
Future<bool> isDuplicateUniqueName(String uniqueName) async {
QuerySnapshot query = await FirebaseFirestore.instance
.collection('PATH_TO_USERS_COLLECTION')
.where('uniqueName', isEqualTo: uniqueName)
.get();
return query.docs.isNotEmpty;
}
// call the above function inside here.
static firebaseSignUpWithEmailAndPassword(String emailAddress, String password, File? image, String name,) async {
if (await isDuplicateUniqueName(name)) {
// UniqueName is duplicate
// return 'Unique name already exists';
}
// ... the rest of your code. Go ahead and create an account.
// remember to save the uniqueName to users collection.
I suggest doing the following steps:
Create your own users collection (for example users) in Firestore, which you might have done already. (I don't think that User is a good class name, since Firebase Authentication is using the same name. Try MyUser or something.)
Add authentication triggers that will ensure that whenever a Firebase user is added or deleted, it will also be added to or deleted from users collection, use Firebase uid as identifier.
Create a solution to check whether a uniqueName already exists in users collection. You can use a Firestore query, but in this case you have to allow unauthenticated access to read users, at least uniqueName field. (Since the user is not authenticated yet at this point.) A Firebase Cloud Function is another option.
When users enter their desired uniqueName, run the check before creating Firebase user. You can do it when user enters this or when you start the signup process.
If uniqueName is unique, you can try to create Firebase user. Be aware, this step can also fail (for example e-mail name taken etc.). Your users document will be created by the authentication trigger you set up in step 2.
Finally, you have to store this uniqueName in users collection. At this point you will have uid of the newly created Firebase user, so you can use Firestore set command with merge option set to true, so you don't overwrite other data.
It is important to note that you can't guarantee that the Firebase trigger already created the new document in users by the time you arrive to point 6, it is very likely that the trigger is still working or not even started yet. That's why you have to use set both in the authentication trigger and in your own code that sets uniqueName: which "arrives" first, will create the document, and the second will update it.
Also, for the same reason, you have to allow inserts and updates into users collection with Firestore rules. This might sound a little scary, but keep in mind that this is only your own user list to keep track of uniqueName, and authentication is based not on this, but on Firebase Authentication's user management which is well protected.
Last comment: this is not a 100% solution. It is quite unlikely, but theoretically can happen, that some else reserves a uniqueName between you check whether it's unique and the user is actually created. To mitigate this, it is a good idead to make the check just before Firebase user is created. Even in this case a slight chance remains for duplicates.
I have website written in plain javascript to keep daily to-do tasks and the app crashed lately because different tasks of the same date was created on accident. My question is...
how can i write an if statement that checks if a document from a collection has a property (in my case the date) that is equal to the one in the input field of my form. i guess it should check after i click submit? if it exists, creation should be denyed, if not, ok to proceed.
i am using cloud firestore by the way... many thanks in advance for the help!
First, make a query to get a document that has same date:
var query = db.collection("yourCollectionName").where("date", "==", dateInInputfield);
query.get().then(function(querySnapshot) {
if (querySnapshot.empty) {
//empty
} else {
// not empty
}
});
If empty{you can proceed}, if notEmpty{some other task already exist on same date}
If you are making an app like this, a cleaner approach will be to name the id of a document as it's date, for eg. if a task is created at timestamp of 1234567, create a document named 1234567 and inside it, store all the necessary information.
By following this approach, if you create a new task, simply fetch a document by the name in inputfield,
var docRef = db.collection("yourCollectionName").doc("date");
docRef.get().then(function(doc) {
if (doc.exists) {
//this means some other document already exists
} else {
//safe to create a new document by this date.
}
}).catch(function(error) {
console.log("Error:", error);
});
Disclaimer, I am trying to self-teach myself development. I am building a hybrid mobile app using Ionic 1 and now Firebase 3 for my database and authentication.
For my scenario, in short, I'm trying to display a list of 'friends' for the user that is currently logged in. Here is the current data structure I have (the relevant part anyway):
Data Structure
I have a line of code that does return me what I want:
var friends = $firebaseArray(ref.child('users').child('-KXcxMXkKs46Xv4-JUgW').child('friends'));
Of course, that can't work because there is a nice little hard coded value in there.
So, I looked into how to retrieve the current UID so I could replace the hard coded value. But after running the following bit of code through, the first node under user is not the UID (it is some other auto generated value that I don't really know how it got there). The UID is actually within the id field.
var ref = firebase.database().ref();
authObj = $firebaseAuth();
var firebaseUser = authObj.$getAuth();
console.log(firebaseUser.uid);
So, ultimately what I would love is to be able to change the data structure so that the UID is the first node under Users, but I can't seem to find documentation to do that. I looked at this other stack thread, but it is for an outdated version and I can't seem to connect the dots. Other thread
Though, if I can't change the structure, I still need to figure out how to access that friends node for the current user, one way or another.
Thank you in advance. This is my first stackoverflow post, so be gentle.
Update:
Per Frank's comment, this is the code that I execute to create users - $add is what is creating the push id (-KXcxM...).
createProfile: function(uid, user) {
var profile = {
id: uid,
email: user.email,
registered_in: Date()
// a number of other things
};
var messagesRef = $firebaseArray(firebase.database().ref().child("users"));
messagesRef.$add(profile);
},
register: function(user) {
return auth.$createUserWithEmailAndPassword(user.email, user.password)
.then(function(firebaseUser) {
console.log("User created with uid: " + firebaseUser.uid);
Auth.createProfile(firebaseUser.uid, user);
Utils.alertshow("Success!","Your user has been registered.");
})
.catch(function(error) {
Utils.alertshow("Error.","Some helpful error message.");
console.log("Error: " + error);
});
}
Instead of creating a $firebaseArray and calling $add on it, you can just store the user using the regular Firebase JavaScript SDK:
createProfile: function(uid, user) {
var profile = {
id: uid,
email: user.email
};
firebase.database().ref().child("users").child(uid).set(profile);
}
Since AngularFire is built on top of the Firebase JavaScript SDK, the two interact nicely with each other. So if you have any existing $firebaseArray on users it will pick up the new profile too.
My firbase database looks like this:
app
users
-gn4t9u4ut304u9g4
email
uid
How do I reference email and uid? When I try this:
$rootScope.dashtype.child('users').orderByChild('uid').equalTo($rootScope.auth.uid).on('value', function(snapshot){
$rootScope.user = snapshot.val();
console.log($rootScope.user);
})
I get the correct object, but with the unique id as root:
Object {-JvaZVrWGvJis0AYocBa: Object}
And because this is a dynamic property, I don't know how to reference the child objects. I just want to be able to access the user fields like this: $rootScope.user.email etc.
Since you're requesting a value, you get a list of users as a result. It may only be one user, but it's still a list of one.
You will have to loop over the snapshot, to get to the child node:
$rootScope.dashtype.child('users').orderByChild('uid').equalTo($rootScope.auth.uid).on('value', function(snapshot){
snapshot.forEach(function(userSnapshot) {
$rootScope.user = userSnapshot.val();
console.log($rootScope.user);
});
});
Since there's only a single user in the list, the loop for execute just once.
You are mixing regular Firebase JavaScript with AngularFire here. This means that you will need to inform AngularJS that you updated the scope, so that it will rerender the view:
$rootScope.dashtype.child('users').orderByChild('uid').equalTo($rootScope.auth.uid).on('value', function(snapshot){
snapshot.forEach(function(userSnapshot) {
$timeout(function() {
$rootScope.user = userSnapshot.val();
console.log($rootScope.user);
});
});
});
I am saving logged in userId with each record saved in my Meteor app collection as shown in the example below, yet I was wondering if there was any way in Meteor where I can retrieve user name based on the user saved id without have to make another query on the users collection? In Node.js / mongoose there was this Populate function, but I can't seem to find similar package / function in Meteor. So I was wondering if someone can help me by suggesting a resolution to this problem (if any). thanks
var newInvoice = {
customerid: $(e.target).find('[name=customer]').val(),
userid: Meteor.userId(),
//....more fields here
}
Meteor.call('saveInvoice', newInvoice, function(error, id){
if(error)
return alert(error.reason);
});