How to call Cloud Function from Firebase in Flutter? - firebase

I am trying to update some values that I will enter from my Flutter app to FireStore using Cloud Functions. Here is my code so far:
This is my Cloud function (in JavaScript, index.js) to update a document in FireStore:
exports.update = functions.https.onRequest((req, res) => {
const getNewPercentage = req.body;
const getDocument = admin.firestore().collection('waterpercentage').doc('percentage');
getDocument.get().then((doc) => {
if(doc.exists) {
getDocument.update({'percentage': getNewPercentage}).catch(err => {
console.log("Error: ", err);
res.send("500");
})
}
}).catch(err => {
console.log("Error: ", err)
res.send("500");
});
res.send(200);
})
In Flutter, here's what I tried:
Future<void> updateWaterPercentage() async {
HttpsCallable callable = FirebaseFunctions.instance.httpsCallable('update');
//final results = await callable.call(<dynamic, int>{'percentage' : percentage.round()});
log("Calling percentage here: ");
log(percentage.round().toString());
dynamic resp = await callable.call(<double, dynamic> {
percentage : percentage.round(),
});
When I call updateWaterPercentage() from a Button in Flutter, the data doesn't get updated in FireStore. I also tried using:
CloudFunctions.instance.call(
functionName: "update",
parameters: {
"percentage": percentage.round(),
}
);
However, even though I imported 'package:cloud_functions/cloud_functions.dart'; on top, Flutter doesn't recognize CloudFunctions. How can I get the code to call update that takes in a parameter to correctly update a value in Firestore?

You are mixing Callable Cloud Functions and HTTPS Cloud Functions.
Your Cloud Function code corresponds to an HTTP one (functions.https.onRequest((req, res) => {(...)}) but the code in your app declares and calls a Callable one (HttpsCallable callable = FirebaseFunctions.instance.httpsCallable('update');).
In addition, in your HTTPS Cloud Function code, you send back a response before the asynchronous operation is complete (see the last line res.send(200);).
So, to fix the problem:
You could call the HTTPS Cloud Function from your flutter app with the http package;
But the best would probably be to adapt your Cloud Function to be a Callable one in order to get the advantages of a Callable, including the use of the cloud_functions package which makes very easy to call the CF from your app. Something along the following lines.
exports.update = functions.https.onCall((data, context) => {
const getNewPercentage = data.percentage;
const documentRef = admin.firestore().collection('waterpercentage').doc('percentage');
return documentRef.get()
.then((doc) => {
if (doc.exists) {
return documentRef.update({ 'percentage': getNewPercentage });
} else {
throw new Error('Doc does not exist');
}
})
.then(() => {
return { result: "doc updated" };
})
.catch(err => {
console.log("Error: ", err)
// See the doc: https://firebase.google.com/docs/functions/callable#handle_errors
});
});

Related

Google Functions - httpCallable.onRequest display error message [duplicate]

I am trying to update some values that I will enter from my Flutter app to FireStore using Cloud Functions. Here is my code so far:
This is my Cloud function (in JavaScript, index.js) to update a document in FireStore:
exports.update = functions.https.onRequest((req, res) => {
const getNewPercentage = req.body;
const getDocument = admin.firestore().collection('waterpercentage').doc('percentage');
getDocument.get().then((doc) => {
if(doc.exists) {
getDocument.update({'percentage': getNewPercentage}).catch(err => {
console.log("Error: ", err);
res.send("500");
})
}
}).catch(err => {
console.log("Error: ", err)
res.send("500");
});
res.send(200);
})
In Flutter, here's what I tried:
Future<void> updateWaterPercentage() async {
HttpsCallable callable = FirebaseFunctions.instance.httpsCallable('update');
//final results = await callable.call(<dynamic, int>{'percentage' : percentage.round()});
log("Calling percentage here: ");
log(percentage.round().toString());
dynamic resp = await callable.call(<double, dynamic> {
percentage : percentage.round(),
});
When I call updateWaterPercentage() from a Button in Flutter, the data doesn't get updated in FireStore. I also tried using:
CloudFunctions.instance.call(
functionName: "update",
parameters: {
"percentage": percentage.round(),
}
);
However, even though I imported 'package:cloud_functions/cloud_functions.dart'; on top, Flutter doesn't recognize CloudFunctions. How can I get the code to call update that takes in a parameter to correctly update a value in Firestore?
You are mixing Callable Cloud Functions and HTTPS Cloud Functions.
Your Cloud Function code corresponds to an HTTP one (functions.https.onRequest((req, res) => {(...)}) but the code in your app declares and calls a Callable one (HttpsCallable callable = FirebaseFunctions.instance.httpsCallable('update');).
In addition, in your HTTPS Cloud Function code, you send back a response before the asynchronous operation is complete (see the last line res.send(200);).
So, to fix the problem:
You could call the HTTPS Cloud Function from your flutter app with the http package;
But the best would probably be to adapt your Cloud Function to be a Callable one in order to get the advantages of a Callable, including the use of the cloud_functions package which makes very easy to call the CF from your app. Something along the following lines.
exports.update = functions.https.onCall((data, context) => {
const getNewPercentage = data.percentage;
const documentRef = admin.firestore().collection('waterpercentage').doc('percentage');
return documentRef.get()
.then((doc) => {
if (doc.exists) {
return documentRef.update({ 'percentage': getNewPercentage });
} else {
throw new Error('Doc does not exist');
}
})
.then(() => {
return { result: "doc updated" };
})
.catch(err => {
console.log("Error: ", err)
// See the doc: https://firebase.google.com/docs/functions/callable#handle_errors
});
});

Trouble reading data in Firebase Cloud Function

Trying to read a pushToken from a given user in the users collection (after an update operation on another collection) returns undefined
exports.addDenuncia = functions.firestore
.document('Denuncias/{denunciaID}')
.onWrite((snap, context) => {
const doc = snap.after.data()
const classificadoId = doc.cid
const idTo = doc.peerId
db.collection('Classificados').doc(classificadoId)
.update({
aprovado: false
})
.then(r => {
getToken(idTo).then(token => {
// sendMsg...
})
}).catch(updateErr => {
console.log("updateErr: " + updateErr)
})
async function getToken(id) {
let response = "getTokenResponse"
console.log("id in getToken: " + id)
return db.collection('users').doc(id).get()
.then(user => {
console.log("user in getToken: " + user.data())
response = user.data().pushToken
})
.catch(e => {
console.log("error get userToken: " + e)
response = e
});
return response
}
return null
});
And this is from the FB console log:
-1:43:33.906 AM Function execution started
-1:43:36.799 AM Function execution took 2894 ms, finished with status: 'ok'
-1:43:43.797 AM id in getToken: Fm1RwJaVfmZoSgNEFHq4sbBgoEh1
-1:43:49.196 AM user in getToken: undefined
-1:43:49.196 AM error get userToken: TypeError: Cannot read property 'pushToken' of undefined
-1:43:49.196 AM returned token: undefined
And we can see in this screenshot from the db that the doc does exist:
Hope someone can point me to what I'm doing wrong here.
added screenshot of second example of #Renaud as deployed:
As Doug wrote in his comment, you need to "return a promise from the top level function that resolves when all the async work is complete". He also explains that very well in the official video series: https://firebase.google.com/docs/functions/video-series/ (in particular the 3 videos titled "Learn JavaScript Promises"). You should definitely watch them, highly recommended!
So, the following modifications to your code should work (untested):
exports.addDenuncia = functions.firestore
.document('Denuncias/{denunciaID}')
.onWrite(async (snap, context) => { // <- note the async keyword
try {
const doc = snap.after.data()
const classificadoId = doc.cid
const idTo = doc.peerId
await db.collection('Classificados').doc(classificadoId)
.update({
aprovado: false
});
const userToSnapshot = await db.collection('users').doc(idTo).get();
const token = userToSnapshot.data().pushToken;
await sendMsg(token); // <- Here you should take extra care to correctly deal with the asynchronous character of the sendMsg operation
return null; // <-- This return is key, in order to indicate to the Cloud Function platform that all the asynchronous work is done
} catch (error) {
console.log(error);
return null;
}
});
Since you use an async function in your code, I've used the async/await syntax but we could very well write it by chaining the promises with the then() method, as shown below.
Also, I am not sure, in your case, that it adds any value to put the code that gets the token in a function (unless you want to call it from other Cloud Functions but then you should move it out of the addDenuncia Cloud Function). That's why it has been replaced by two lines of code within the main try block.
Version with chaining promises via the then() method
In this version we chain the different promises returned by the asynchronous methods with the then() method. Compared to the async/await version above, it shows very clearly what means "to return a promise from the top level function that resolves when all the asynchronous work is complete".
exports.addDenuncia = functions.firestore
.document('Denuncias/{denunciaID}')
.onWrite((snap, context) => { // <- no more async keyword
const doc = snap.after.data()
const classificadoId = doc.cid
const idTo = doc.peerId
return db.collection('Classificados').doc(classificadoId) // <- we return a promise from the top level function
.update({
aprovado: false
})
.then(() => {
return db.collection('users').doc(idTo).get();
})
.then(userToSnapshot => {
if {!userToSnapshot.exists) {
throw new Error('No document for the idTo user');
}
const token = userToSnapshot.data().pushToken;
return sendMsg(token); // Again, here we make the assumption that sendMsg is an asynchronous function
})
.catch(error => {
console.log(error);
return null;
})
});

Using a callable function to send data back to the client from Firebase

I have created a callable Cloud Function to read data from Firebase and send back the results to the client, however, only "null" is being returned to the client.
exports.user_get = functions.https.onCall((data, context) => {
if (context.auth && data) {
return admin.firestore().doc("users/" + context.auth.uid).get()
.then(function (doc) {
return { doc.data() };
})
.catch(function (error) {
console.log(error);
return error;
})
} return
});
I just reproduced your case connecting from a Cloud Function with a Firestore database and retriving data. As I can see you are trying to access the field in a wrong way when you are using "users/" + context.auth.uid, the method can't find the field so its returning a null value.
I just followed this Quickstart using a server client library documentation to populate a Firestore database and make a Get from it with node.js.
After that i followed this Deploying from GCP Console documentation in order to deploy a HTTP triggered Cloud Function with the following function
exports.helloWorld = (req, res) => {
firestore.collection('users').get()
.then((snapshot) => {
snapshot.forEach((doc) => {
console.log(doc.id, '=>', doc.data().born);
let ans = {
date : doc.data().born
};
res.status(200).send(ans);
});
})
And this is returning the desired field.
You can take a look of my entire example code here
This is because you are making a query from a database firestore, however the cloud support team has made it very cool to protect your applications from data leakages and so in a callable function as the name suggest you can only return data you passed to the same callable function through the data parameter and nothing else. if you try to access a database i suggest you use an onRequest Function and use the endpoint to get you data. that way you not only protect your database but avoid data and memory leakage.
examples of what you can return from a callable function
exports.sayHello = functions.https.onCall((data, context) => {
const name = data.name;
console.log(`hello ${name}`);
return `It was really fun working with you ${name}`;
});
first create a function in your index.js file and accept data through the data parameter but as i said you can only return data you passed through the data parameter.
now call the function
this is in the frontend code (attach an event listener to a button or something and trigger it
/* jsut say hello from firebase */
callButton.addEventListener('click', () => {
const sayHello = firebase.functions().httpsCallable('getAllUsers');
sayHello().then(resutls => {
console.log("users >>> ", resutls);
});
});
you can get your data using an onRequest like so
/* get users */
exports.getAllUsers = functions.https.onRequest((request, response) => {
cors(request, response, () => {
const data = admin.firestore().collection("users");
const users = [];
data.get().then((snapshot) => {
snapshot.docs.forEach((doc) => {
users.push(doc.data());
});
return response.status(200).send(users);
});
});
});
using a fetch() in your frontend code to get the response of the new onRequest function you can get the endpoint to the function in your firebase console dashboard.
but not that to hit the endpoint from your frontend code you need to add cors to your firebase cloud functions to allow access to the endpoint.
you can do that by just adding this line to the top of your index.js file of the firebase functions directory
const cors = require("cors")({origin: true});

Google Translate API and Firebase Firestore are killing each other

We're trying to write a Google Cloud Function that gets a translation from Google Translate API, and then write the results to our Firebase Firestore database. Each works alone, but together nothing works. In other words, we can get a translation from Google Translate. We can write data to Firestore. But if we try to do both, we don't get a translation back from Google Translate, and nothing is written to Firebase. We get no error messages. We've tried the code with async await and with promises. Here's the code with promises:
exports.Google_EStranslateEN = functions.firestore.document('Users/{userID}/Spanish/Translation_Request').onUpdate((change, context) => {
if (change.after.data().word != undefined) {
const {Translate} = require('#google-cloud/translate');
const projectId = 'myProject-cd99d';
const translate = new Translate({
projectId: projectId,
});
// The text to translate
const text = change.after.data().word;
// The target language
const target = 'en';
let translationArray = []; // clear translation array
translate.translate(text, target)
.then(results => {
translation = results[0];
translationArray.push(translation);
try {
// write translation to dictionary
admin.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(text).collection('Translations').doc('English').set({
'translationArray': translationArray,
'language': 'en',
'longLanguage': 'English'
})
.then(function() {
console.log("Translation written");
})
.catch(function(error) {
console.error(error);
});
} catch (error) {
console.error(error);
}
})
.catch(error => {
console.error('ERROR:', error);
});
}
});
Here's the same code with async await:
exports.Google_EStranslateEN = functions.firestore.document('Users/{userID}/Spanish/Translation_Request').onUpdate((change, context) => { // triggers when browser writes a request word to the database
if (change.after.data().word != undefined) {
async function getTranslation() {
try {
let translationArray = []; // clear translation array
const {Translate} = require('#google-cloud/translate');
const projectId = 'myProject-cd99d';
const translate = new Translate({
projectId: projectId,
});
// The text to translate
const text = change.after.data().word;
const options = {
to: 'en',
from: 'es',
format: 'text'
}
let [translations] = await translate.translate(text, options);
translations = Array.isArray(translations) ? translations : [translations]; // If translations is an array, leave it alone; if not, put it in an array
translationArray.push(translations[0]);
await admin.firestore().collection('Dictionaries').doc('Spanish').collection('Words').doc(text).collection('Translations').doc('English').set({
'translationArray': translationArray,
'language': 'en',
'longLanguage': 'English'
})
.then(function() {
console.log("Translation written");
})
.catch(function(error) {
console.error(error);
});
// };
} catch (error) {
console.error(error);
}
} // close getTranslation
getTranslation();
}
});
You're not returning a promise that's resolved when all the async work is complete. If you don't do that, Cloud Functions assumes that all your work is complete, and will clamp down on all resources, and any pending work will be shut down.
The promise returned by translate.translate().then().catch() is being ignored. Your nested call to admin.firestore()...set() has a similar problem. It's not sufficient to just call then() and catch() on every promise because then() and catch() both return yet another promise.
You're also unnecessarily mixing usage of try/catch with catch() on the promise. You don't need both strategies for error handling, just one or the other.
When you used await in your second example, you forced JavaScript to pause until the async work represented by the promise returned by set() was complete. This allowed your function to return only after all the work was finished, which is why it worked correctly.
You might be helped by watching my video series on use of promises and async/await in Cloud Functions. Proper handling of promises is crucial to creating a correctly working function.

How to get data from Firestore in Cloud Function?

I need to know what I'm doing wrong here?
I'm calling this function from Flutter. The call back is getting done correctly and the first & second prints are coming in the "log" on Firbase. But getting undefined from the "Firestore"!!
This is the code in the Cloud Function:
var functions = require("firebase-functions");
let admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
admin.firestore().settings({ timestampsInSnapshots: true });
exports.storeContact5 = functions.https.onCall((data, context) => {
// First print is working fine
console.log('test');
var recieverId = 'WqHxLoYvRxR9UK8sFJZ9WxTOIE32';
const check = admin.firestore().collection('users').doc(recieverId).get();
check.then(testValue => {
console.log(testValue.data.nickname);
return true;
}).catch(err => {
console.log('Error getting document', err);
});
console.log('test2');
// Return to flutter App (Working fine)
return {
repeat_message: 'ok!'
}
});
Screenshot for Firebase Log
You should do testValue.data().nickname and not testValue.data.nickname, see https://firebase.google.com/docs/firestore/query-data/get-data#get_a_document and https://firebase.google.com/docs/reference/js/firebase.firestore.DocumentSnapshot#data.
Also, you should return a result only once and you should not return outside of the .then() if you want to return the result of the asynchronous operation.
In addition, see here how to handle errors: https://firebase.google.com/docs/functions/callable#handle_errors
So you may do as follows:
exports.storeContact5 = functions.https.onCall((data, context) => {
// First print is working fine
console.log('test');
var recieverId = 'WqHxLoYvRxR9UK8sFJZ9WxTOIE32';
const check = admin.firestore().collection('users').doc(recieverId).get();
return check.then(testValue => {
console.log(testValue.data().nickname);
return {repeat_message: 'ok!'};
}).catch(err => {
console.log('Error getting document', err);
throw new functions.https.HttpsError('Error getting document', err);
});
});
I would suggest you watch the videos from the official series: https://firebase.google.com/docs/functions/video-series/, in particular the ones titled "Learn JavaScript Promises"

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