I have been searching all over on how to implement firebase functions with a flutter application. It does not seem like there is an SDK available (yet). I've also tried adding the gradle dependency implementation 'com.google.firebase:firebase-functions:15.0.0' to my app/build.gradle but this causes build errors.
Has anyone done an implementation that works? I am unable to find any documentation on how to handle credentials and the transport of data in order to build my own firebase functions call.
I have created a rough outline of how I am thinking this is intended to work, but may be way off base.
Future<dynamic> updateProfile(String uid, AccountMasterViewModel avm) async {
Uri uri = Uri.parse(finalizeProfileFunctionURL);
var httpClient = new HttpClient();
String _result = '';
try {
return await httpClient
.postUrl(uri)
.then((HttpClientRequest request) {
return request.close();
// authentication??
// Fields and data??
})
.then((HttpClientResponse response) async {
print(response.transform(new Utf8Codec().decoder).join());
if (response.statusCode == HttpStatus.OK) {
String json = await response.transform(new Utf8Codec().decoder).join();
_result = jsonDecode(json);
// Do some work
return json;
}
else {
return ':\nHttp status ${response.statusCode}';
}
});
}
catch (exception) {
return 'Failed ' + exception.toString();
}
}
I'd like to be able to send an object, like
{
accountID: src.accountID,
accountName: src.name,
accountImg: src.image
}
and then handle the response. But as I said, I can't find any working examples or tutorials on how to do this. It's fairly simple to do this client size and talk directly to the database, however, there are validations and data components that need to be hidden from the client, so cloud functions is the way I would like to do this.
Yes, there is a cloud_function package available here: https://pub.dartlang.org/packages/cloud_function.
so as to make a call to the function you can just call
CloudFunctions.instance.call(
functionName: 'yourCloudFunction',
parameters: <String, dynamic>{
'param1': 'this is just a test',
'param2': 'hi there',
},
);
An updated answer to calling Firebase's Cloud Functions in Flutter would be
var callable = CloudFunctions.instance.getHttpsCallable(functionName: 'functionName'); // replace 'functionName' with the name of your function
dynamic response = callable.call(<String, dynamic>{
'param1': param1 //replace param1 with the name of the parameter in the Cloud Function and the value you want to insert
}).catchError((onError) {
//Handle your error here if the function failed
});
This is a good tutorial on cloud functions in flutter which helped me:
https://rominirani.com/tutorial-flutter-app-powered-by-google-cloud-functions-3eab0df5f957
Cloud functions can be triggered by data change triggers in the realtime database, Firestore, or Datastore, as well as authentication triggers.
You could just persist
{
accountID: src.accountID,
accountName: src.name,
accountImg: src.image
}
to the database and register a trigger that runs a Cloud Function when data at a specific path is inserted, updated, or deleted.
https://firebase.google.com/docs/functions/firestore-events
Related
I've followed the Firestore documentation with relation to transactions, and I think I have it all sorted correctly, but in testing I am noticing issues with my documents not getting updated properly sometimes. It is possible that multiple versions of the document could be submitted to the function in a very short interval, but I am only interested in only ever keeping the most recent version.
My general logic is this:
New/Updated document is sent to cloud function
Check if document already exists in Firestore, and if not, add it.
If it does exist, check that it is "newer" than the instance in firestore, if it is, update it.
Otherwise, don't do anything.
Here is the code from my function that attempts to accomplish this...I would love some feedback if this is correct/best way to do this:
const ocsFlight = req.body;
const procFlight = processOcsFlightEvent(ocsFlight);
try {
const ocsFlightRef = db.collection(collection).doc(procFlight.fltId);
const originalFlight = await ocsFlightRef.get();
if (!originalFlight.exists) {
const response = await ocsFlightRef.set(procFlight);
console.log("Record Added: ", JSON.stringify(procFlight));
res.status(201).json(response); // 201 - Created
return;
}
await db.runTransaction(async (t) => {
const doc = await t.get(ocsFlightRef);
const flightDoc = doc.data();
if (flightDoc.recordModified <= procFlight.recordModified) {
t.update(ocsFlightRef, procFlight);
console.log("Record Updated: ", JSON.stringify(procFlight));
res.status(200).json("Record Updated");
return;
}
console.log("Record isn't newer, nothing changed.");
console.log("Record:", JSON.stringify("Same Flight:", JSON.stringify(procFlight)));
res.status(200).json("Record isn't newer, nothing done.");
return;
});
} catch (error) {
console.log("Error:", JSON.stringify(error));
res.status(500).json(error.message);
}
The Bugs
First, you are trusting the value of req.body to be of the correct shape. If you don't already have type assertions that mirror your security rules for /collection/someFlightId in processOcsFlightEvent, you should add them. This is important because any database operations from the Admin SDKs will bypass your security rules.
The next bug is sending a response to your function inside the transaction. Once you send a response back the client, your function is marked inactive - resources are severely throttled and any network requests may not complete or crash. As a transaction may be retried a handful of times if a database collision is detected, you should make sure to only respond to the client once the transaction has properly completed.
You use set to write the new flight to Firestore, this can lead to trouble when working with transactions as a set operation will cancel all pending transactions at that location. If two function instances are fighting over the same flight ID, this will lead to the problem where the wrong data can be written to the database.
In your current code, you return the result of the ocsFlightRef.set() operation to the client as the body of the HTTP 201 Created response. As the result of the DocumentReference#set() is a WriteResult object, you'll need to properly serialize it if you want to return it to the client and even then, I don't think it will be useful as you don't seem to use it for the other response types. Instead, a HTTP 201 Created response normally includes where the resource was written to as the Location header with no body, but here we'll pass the path in the body. If you start using multiple database instances, including the relevant database may also be useful.
Fixing
The correct way to achieve the desired result would be to do the entire read->check->write process inside of a transaction and only once the transaction has completed, then respond to the client.
So we can send the appropriate response to the client, we can use the return value of the transaction to pass data out of it. We'll pass the type of the change we made ("created" | "updated" | "aborted") and the recordModified value of what was stored in the database. We'll return these along with the resource's path and an appropriate message.
In the case of an error, we'll return a message to show the user as message and the error's Firebase error code (if available) or general message as the error property.
// if not using express to wrangle requests, assert the correct method
if (req.method !== "POST") {
console.log(`Denied ${req.method} request`);
res.status(405) // 405 - Method Not Allowed
.set("Allow", "POST")
.end();
return;
}
const ocsFlight = req.body;
try {
// process AND type check `ocsFlight`
const procFlight = processOcsFlightEvent(ocsFlight);
const ocsFlightRef = db.collection(collection).doc(procFlight.fltId);
const { changeType, recordModified } = await db.runTransaction(async (t) => {
const flightDoc = await t.get(ocsFlightRef);
if (!flightDoc.exists) {
t.set(ocsFlightRef, procFlight);
return {
changeType: "created",
recordModified: procFlight.recordModified
};
}
// only parse the field we need rather than everything
const storedRecordModified = flightDoc.get('recordModified');
if (storedRecordModified <= procFlight.recordModified) {
t.update(ocsFlightRef, procFlight);
return {
changeType: "updated",
recordModified: procFlight.recordModified
};
}
return {
changeType: "aborted",
recordModified: storedRecordModified
};
});
switch (changeType) {
case "updated":
console.log("Record updated: ", JSON.stringify(procFlight));
res.status(200).json({ // 200 - OK
path: ocsFlightRef.path,
message: "Updated",
recordModified,
changeType
});
return;
case "created":
console.log("Record added: ", JSON.stringify(procFlight));
res.status(201).json({ // 201 - Created
path: ocsFlightRef.path,
message: "Created",
recordModified,
changeType
});
return;
case "aborted":
console.log("Outdated record discarded: ", JSON.stringify(procFlight));
res.status(200).json({ // 200 - OK
path: ocsFlightRef.path,
message: "Record isn't newer, nothing done.",
recordModified,
changeType
});
return;
default:
throw new Error("Unexpected value for 'changeType': " + changeType);
}
} catch (error) {
console.log("Error:", JSON.stringify(error));
res.status(500) // 500 - Internal Server Error
.json({
message: "Something went wrong",
// if available, prefer a Firebase error code
error: error.code || error.message
});
}
References
Cloud Firestore Transactions
Cloud Firestore Node SDK Reference
HTTP Event Cloud Functions
I am using Angular 8 and have a form where a user can choose what he wants to query the database for and then click either of two buttons - one to view data in realtime on the website, and the other to download the data.
I thought I could make use of one function to make a query and then call different functions depending on what button the user clicked, using get() for the download and valueChanges() for the realtime data view. But when I try this, I get the following errors in the browser console. (This is with query as type any - if I specify the type as AngularFirestoreCollection I get errors regarding my type for the get() part in VSCode)
ERROR Error: "Uncaught (in promise): TypeError: this.query.get is not
a function
I can add that I previously had two completely separate (working) functions for downloading and viewing in realtime. And for downloading I used the below query. I gather this is actually a Firestore Query, whereas the "query" I'm trying to use in my updated code is an AngularFirestoreCollection. But is there a way I can make some kind of Query/Collection that will work for both get() and valueChanges()?
Old (working) query:
var query = this.afs.collection(collection).ref.where('module', 'in', array_part);
Trying a common function makeQuery():
onSubmit(value, buttonType): void {
if (buttonType=='realtime') {
this.getRealTimeData(value);
}
if (buttonType=='download') {
this.downloadCsv(value);
}
}
async downloadCsv(value) {
this.query = this.makeQuery(value);
this.dataForDownload = await this.getDataForDownload();
this.dataForDownload = JSON.stringify(this.dataForDownload['data']);
console.log('Data: ', this.dataForDownload);
var date = new Date();
var date_str = this.datePipe.transform(date, 'yyyy-MM-ddTHH-mm');
this.makeFileService.downloadFile(this.dataForDownload, 'OPdata-' + date_str);
}
getDataForDownload() {
return this.query.get()
.then(function (querySnapshot) {
var jsonStr = '{"data":[]}';
var dataObj = JSON.parse(jsonStr); //making object we can push to
querySnapshot.forEach(function (doc) {
JSON.stringify(doc.data()), ', id: ', doc.id);
dataObj['data'].push(doc.data());
});
return dataObj;
})
.catch(function (error) {
console.log("Error getting documents: ", error);
});
}
async getRealTimeData(value) {
this.query = await this.makeQuery(value);
this.data = this.query.valueChanges();
}
async makeQuery(value) {
var collection: string;
return this.query = this.afs.collection<DataItem>('CollectionName', ref => ref.where('datetime', '>=', '2020-01-15T09:51:00.000Z').orderBy('datetime', 'desc').limit(100));
}
The valueChanges() is a method used in angularfire to retrieve data from firestore, while the get() method is used to retrieve from firestore but using the vanilla javascript.
Mixing both methods will return an error as you have seen in your code. Therefore, since angularfire was created above the javascript firebase code, then you should be able to use valueChanges() to view data in realtime on the website, and to download the data.
I've been trying to implement just a simple Firebase fetch since November. At this point, I wish I'd just created a new Rails api; it would have been faster.
But everyone insists Firebase is Oh So Simple.
In app.js,
import firebase from 'nativescript-plugin-firebase';
That part seems OK.
Instructions are all over the place after that.
The plugin's ReadMe suggests an initialization:
firebase.init({
// Optionally pass in properties for database, authentication and cloud messaging,
// see their respective docs.
}).then(
function () {
console.log("firebase.init done");
},
function (error) {
console.log("firebase.init error: " + error);
}
);
Several others have insisted that the init code is unnecessary. It does run without errors, but the code he gives after that produces nothing. Also,
const db = firebase.firestore;
const UserStatusCollection = db.collection("UserStatus");
UserStatusCollection.get();
produce an empty object {}.
Here's my Firebase collection:
If I wrap the firebase call in async/await (and no one is showing it as this complicated),
async function getFireStoreData() {
try {
let result = await this.UserStatusCollection.get();
console.log(result);
return result;
}
catch (error) {
console.error(
"UserStatusCollection.get()" + error
);
}
}
And call that
let temp2 = getFireStoreData();
console.log("temp2:" + temp2);
All I ever get is an object promise.
As I said, I wish I had just built up a new Rails API and had a far simpler life since November.
Your getFireStoreData method is asynchronous and you're not awaiting it. That is probably the reason why you're getting a promise back. Try to await getFireStoreData(). See if that works.
Since it's also a promise, you can try to use .then.
getFireStoreData().then(data => {
console.log(data);
})
I have a Google Cloud AutoML NL model ready to use. I wish to link this with my web app with Firebase backend. Following is my code to call. There is authorization issue. I want to understand how to authorize the app to help the client apps get access to AutoML model.
async add(data){
var headers = new Headers();
headers.append('Content-Type:application/json')
var options = {
method: 'POST',
headers,
body: JSON.stringify(data)
}
var request = new Request('https://automl.googleapis.com/v1beta1/projects/project1/locations/us-central1/models/TCN5678:predict', options )
var response = await fetch(request)
var status = await response.status
console.log(status)}
After struggling for hours, finally I could resolve this. I am not sure how it can work for, other than Firebase (and NL AutoML). I used Firebase Cloud Function to work around and used a hidden doc which gives access to AutoML npm. The given code require some changes. Firebase CF is able to authenticate without explicitly authorizing. Following is a suggested code and I am able to get the classification of prediction with AutoML. Hope it helps others too. Lastly, it seems Google docs is a way of testing searching skills and patience, not sure how it helps them:
const automl = require('#google-cloud/automl');
exports.sendToAML = functions.database.ref('/path/to/text').onWrite((snapshot, context) =>{
var client = new automl.PredictionServiceClient({
// optional auth parameters.
});
var formattedName = client.modelPath('bucketId', 'us-central1', 'TCN****3567595');
var payload = {
"textSnippet": {
"content": snapshot.after._data.text,
"mime_type": "text/plain"
},
};
var request = {
name: formattedName,
payload: payload,
};
client.predict(request)
.then(responses => {
var response = responses[0];
return console.log(response.payload[0].classification.score)
})
.catch(err => {
console.error(err);
});
});
`
You should either use service accounts or OAuth 2.0 as the authentication method. Try to avoid the use of API keys as your credentials could be exposed and misused, generating undesired charges.
I have a website for testing purposes hosted via firebase, storing client information on a realtime database which needs to be accessed later. When I do this via a single html document with a script that accesses my reatime database I am able to find information successfuly, but when I copied and pasted that same logic into a cloud function it did not work. I have tried everything I can think of and now when I run the function it executes twice (I am not sure why). The first execution finishes with a http 204 status (no content found). The second execution returns http 500 internal service error. When I checked the logs on firebase it says the error was because "accounts.getValue() is not a function". I think what is happening is on the first execution the function is unable to locate accounts and it executes again without trying to find the accounts, which might be why it can't run accounts.getValue()
I guess my main question is why is my function unable to locate accounts?
geturl is the function I am having trouble with
The structure of my realtime database is
database name
-accounts
-some data
-more data
-more account data
-ActiveQRs
-some data...
My index.js file for cloud functions is
const functions = require('firebase-functions');
const express = require('express');
const cors = require('cors')({origin: true});
var firebase = require("firebase");
var admin = require("firebase-admin");
require("firebase/auth");
require("firebase/database");
//require("firebase/firestore");
//require("firebase/messaging");
require("firebase/functions");
var serviceAccount = require("./serviceKey.json");
// Initialize the app with a service account, granting admin
//privileges
admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: "https://databaseName.firebaseio.com"
});
const displayqr = express();
const geturl = express();
displayqr.get('/displayqr', (request, response) => {
console.log("response sent");
response.send("testio/qrdisplay.html");
});
exports.displayqr = functions.https.onRequest(displayqr);
exports.geturl = functions.https.onCall((email) => {
const mail = email.toString();
var result = "";
result = result + mail;
var accounts =
admin.database().ref("livsuiteform/accounts");
result = (accounts.getValue());
accounts.orderByKey().on("value", function(snapshot) {
snapshot.forEach(function(data) {
if (data.child("Email").val() == mail) {
var firstName = data.child("FirstName").val();
var lastName = data.child("LastName").val();
result = firstname;
result = "if loop entered";
} // end if
// return "name not found";
}); // end for each
}); // end order by
return result;
});
TLDR; follow this tutorial on how to build and deploy callable functions for your mobile app.
There are multiple reasons for why your functions aren't working as you expect.
You are including the client-side version of Firebase (var firebase = require("firebase");). You shouldn't use or even require the client-side version. Instead just use Firebase Admin (docs) to access any data. If you need certain user permissions when accessing the DB from the Admin SDK, here is a good example of how to achieve that (Scroll down to "You can still perform user-authorized changes...").
You have mixed different Admin SDK references. getValue() is part of the Admin SDK for Java. You should use the JavaScript equivalent val(). Also, in your code, accounts is a Reference and not a DataSnapshot.
You aren't returning your Promise's. This can be a source of inconsistency in your function execution later SO Question.
You aren't returning anything from your initial function. If you don't return anything, then nothing will get returned to your app. The solution is the same as 3's solution: return your Promise.
You shouldn't use on in Firebase Functions. You should use once. The difference is that on doesn't return a Promise while once does. It returns a function that is used to detach the listener.
I know this is a lot of bullet points and pointing out problems in your code, but I just didn't want give a shallow answer which resulted in you asking another question and waiting another ~2 hours (at the time of writing) for an answer.
I hope this helps!
Code
exports.geturl = functions.https.onCall((email) => {
const mail = email.toString();
var result = "";
result = result + mail;
var accounts = admin.database().ref("livsuiteform/accounts");
return accounts.orderByKey().once("value")
.then(function (snapshot) {
snapshot.forEach(function (data) {
if (data.child("Email").val() == mail) {
var firstName = data.child("FirstName").val();
var lastName = data.child("LastName").val();
result = firstName;
result = "if loop entered";
} // end if
// return "name not found";
}); // end for each
return result;
}); // end order by
});