I use Google Cloud Functions to create an API endpoint for my users to interact with the Realtime Database.
The problem I have is that I'm not sure how the code works. I have a helper function doSomething that I need to call only once, but I have a suspicion that there are cases where it can be called twice or possibly more (when multiple users call the API at the same time and the update operation hasn't been processed by the DB yet). Is it possible? Does it mean I need to use a transaction method? Thank you!
DB structure
{
somePath: {
someSubPath: null
}
}
Google Cloud Functions code
const functions = require('firebase-functions')
const admin = require('firebase-admin')
const cors = require('cors')({origin: true});
admin.initializeApp(functions.config().firebase)
// API ENDPOINT
exports.test = functions.https.onRequest((req, res) => {
cors(req, res, () => {
admin.database().ref('/somePath/someSubPath').once('value')
.then(snapshot => {
const value = snapshot.val()
if (value) return res.status(400).send({ message: 'doSomethingAlreadyCalled' })
doSomething()
const updates = { '/somePath/someSubPath': true }
return admin.database().ref().update(updates)
.then(() => res.status(200).send({ message: 'OK' }))
})
.catch(error => res.status(400).send({ message: 'updateError' }))
})
})
// HELPERS
const doSomething = () => {
// needs to be called only once
}
I believe you were downvoted due to the above pseudocode not making complete sense and there being no log or output of what your code is actually doing in your question. Not having a complete picture makes it hard for us to help you.
Just Going from your structure in the question, your actual code could be calling twice due to function hoisting. Whenever I have this issue, I’ll go back to the api documentation and try to restructure my code from rereading.
HTH
Related
I've been playing around with stripe and would like to learn how to get ephemeral keys in the following way:
Back-end:
//Stripe API requirement for payment
exports.stripeEphemeralKey = functions.https.onCall((data, context) => {
const uid = context.auth.uid;
//Get values
admin.database().ref().child("users").child(uid)
.on("value", (snapshot) =>{
//Get user data
let user = snapshot.val()
//Log data
console.log("Create ephemeral key for:")
console.log(user)
//Create ephemeral key
stripe.ephemeralKeys.create(
{customer: user.customerid },
{stripe_version: '2018-11-08'}
)
.then((key) => {
console.log(key)
console.log("Succesful path. Ephemeral created.")
return "Testing"
})
.catch((err) => {
console.log("Unsuccesful path. Ephemeral not created.")
console.log(err)
return {
valid: false,
data: "Error creating Stripe key"
}
})
})
})
Client-side:
functions.httpsCallable("stripeEphemeralKey").call(["text": "Testing"]) { (result, error) in
print(result?.data)
}
I have tested this code by replacing the body of the stripeEphemeralKey with a simple "Testing" string and that returns just fine. But with the code above I just get Optional() back.
For testing I added lots of console logs. Firebase logs show the execution path gets to the "Succesful path. Ephemeral created." log, and furthermore I can actually see the ephemeral key I get back from stripe.
So, what is the proper correct way to get the ephemeral key in Swift for iOS using the onCall Firebase function?
The backend does what it should, but I can't seem to get the answer back.
Thank you.
The backend does not actually do what it should do. You're doing at least two things wrong here.
First, your callable function needs to return a promise that resolves with the value that you want to send to the client. Right now, your function callback isn't returning anything at all, which means the client won't receive anything. You have return values inside promise handlers, but you need a top-level return statement.
Second, you're using on() to read data from Realtime Database, which attaches a listener that persists until it's removed. This is almost certainly never what you want to do in a Cloud Function. Instead, use once() to get a single snapshot of the data you want to read, and act on that.
For my own reference, and those who might find this helpful:
//Stripe API requirement for payment
exports.stripeEphemeralKey = functions.https.onCall((data, context) => {
const uid = context.auth.uid;
return admin.database().ref().child("users").child(uid)
.once("value", (snapshot) =>{
console.log(snapshot.val() )
})
.then( (snap) => {
const customer = snap.val()
//Log data
console.log("Create ephemeral key for:")
console.log(customer)
//Create ephemeral key
return stripe.ephemeralKeys.create(
{customer: customer.customerid },
{stripe_version: '2018-11-08'}
)
.then((key) => {
console.log(key)
console.log("Succesful path. Ephemeral created.")
return {
valid: true,
data: key
}
})
.catch((err) => {
console.log("Unsuccesful path. Ephemeral not created.")
console.log(err)
return {
valid: false,
data: "Error creating Stripe key"
}
})
})
.catch( err => {
console.log("Unsuccesful path. Ephemeral not created.")
console.log(err)
return {
valid: false,
data: "Error gettting customerid"
}
})
})
The key seems to be to chain the initial database request with .then(), and do our our work chaining the returns uninterrupted as we use functions that return promises. In particular, placing my work-code inside the callback on the original admin.database().ref().once() function did not work for me.
I am new to this kind of programming, so someone who knows about this might the why better.
I have a call back function which is getting data from an external API and depends on a data check I have tried for a slot elicitation inside callback but looks like elicitation is not working inside the callback. Please find the code snippet below,
GetCustomerDetails().then(response => {
var serializedcustomerDetails = convert.xml2json(response.data, {
compact: true,
spaces: 2
});
var customerDetails = JSON.parse(serializedcustomerDetails);
let filteredCustomerDetails = _.filter(customerDetails.CustomerInfo.CustomerDetails, function (o) {
return o.CustomerName._text.includes(customerName);
})
if (filteredCustomerDetails.length == 1) {
callback(elicitSlot(outputSessionAttributes, intentRequest.currentIntent.name,
intentRequest.currentIntent.slots, 'CustomerCode', {
contentType: 'PlainText',
content: `Do you mean ${filteredCustomerDetails[0].CustomerName._text} of ${filteredCustomerDetails[0].SpecialityName._text} department?`
}));
return;
}
}).catch(error => {
console.log(`${error}`)
})
This is my first Awnser on stack so please bear with me.
I have come accross the same problem in a recent project and there are a few things that you can check.
How long does the API call take?
If your API call takes a long time it will be worth checking the timeout settings on your Lambda function. AWS Console -> Lambda -> Your Function -> Basic settings -> Timeout.
Does your Lambda function finish before the API call is done?
I fixed this issue by building a node module to handle my business logic, the module has a function called getNextSlot it returns as a Promise. Inside this function I check the incoming event and figure out which slot I need to elicit next, part of my flow is to call an API endpoint that takes around 10 seconds to complete.
I use the request-promise package to make the api call, this node module makes sure that the lambda function keeps running while the call is running.
exports.getData = function (url, data) {
var pr = require("request-promise");
var options = {
method: 'POST',
url: 'api.example',
qs: {},
headers:
{
'Content-Type': 'application/json'
},
body: {
"example": data
},
json: true,
timeout: 60000
};
return pr(options);
}
In my main code I call this function as:
apiModule.getData("test", "data")
.then(function (data) {
//Execute callback
})
.catch(function (error) {
console.log(error);
reject(error);
});
This solved the issue for me anyways.
Thanks,
I Created a android app in which if a press a button and value changes in Firebase database (0/1) , i want to do this using google assistant, please help me out, i searched out but didn't found any relevant guide please help me out
The code to do this is fairly straightforward - in your webhook fulfillment you'll need a Firebase database object, which I call fbdb below. In your Intent handler, you'll get a reference to the location you want to change and make the change.
In Javascript, this might look something like this:
app.intent('value.update', conv => {
var newValue = conv.prameters.value;
var ref = fbdb.ref('path/to/value');
return ref.set(newValue)
.then(result => {
return conv.ask(`Ok, I've set it to ${newValue}, what do you want to do now?`);
})
.catch(err => {
console.error( err );
return conv.close('I had a problem with the database. Try again later.');
});
return
});
The real problem you have is what user you want to use to do the update. You can do this with an admin-level connection, which can give you broad access beyond what your security rules allow. Consult the authentication guides and be careful.
I am actually working on a project using Dialogflow webhook and integrated Firebase database. To make this posible you have to use the fulfilment on JSON format ( you cant call firebasedatabase in the way you are doing)
Here is an example to call firebase database and display a simple text on a function.
First you have to take the variable from the json.. its something loike this (on my case, it depends on your Entity Name, in my case it was "tema")
var concepto = request.body.queryResult.parameters.tema;
and then in your function:
'Sample': () => {
db.child(variable).child("DESCRIP").once('value', snap => {
var descript = snap.val(); //firebasedata
let responseToUser = {
"fulfillmentMessages": [
{ //RESPONSE FOR WEB PLATFORM===================================
'platform': 'PLATFORM_UNSPECIFIED',
"text": {
"text": [
"Esta es una respuesta por escritura de PLATFORM_UNSPECIFIED" + descript;
]
},
}
]
}
sendResponse(responseToUser); // Send simple response to user
});
},
these are links to format your json:
Para formatear JSON:
A) https://cloud.google.com/dialogflow-enterprise/docs/reference/rest/Shared.Types/Platform
B) https://cloud.google.com/dialogflow-enterprise/docs/reference/rest/Shared.Types/Message#Text
And finally this is a sample that helped a lot!!
https://www.youtube.com/watch?v=FuKPQJoHJ_g
Nice day!
after searching out i find guide which can help on this :
we need to first create chat bot on dialogflow/ api.pi
Then need to train our bot and need to use webhook as fullfillment in
response.
Now we need to setup firebase-tools for sending reply and doing
changes in firebase database.
At last we need to integrate dialogflow with google assistant using google-actions
Here is my sample code i used :
`var admin = require('firebase-admin');
const functions = require('firebase-functions');
admin.initializeApp(functions.config().firebase);
var database = admin.database();
// // Create and Deploy Your First Cloud Functions
// // https://firebase.google.com/docs/functions/write-firebase-functions
//
exports.hello = functions.https.onRequest((request, response) => {
let params = request.body.result.parameters;
database.ref().set(params);
response.send({
speech: "Light controlled successfully"
});
});`
I am running an NodeJS server with the following code to connect to the Hyperledger Runtime:
const BusinessNetworkConnection = require("composer-client")
.BusinessNetworkConnection;
this.businessNetworkConnection = new BusinessNetworkConnection();
this.CONNECTION_PROFILE_NAME = "hlfv1";
this.businessNetworkIdentifier = "testNetwork";
this.businessNetworkConnection
.connect(
this.CONNECTION_PROFILE_NAME,
this.businessNetworkIdentifier,
"admin",
"adminpwd"
)
.then(result => {
this.businessNetworkDefinition = result;
console.log("BusinessNetworkConnection: ", result);
})
.then(() => {
// Subscribe to events.
this.businessNetworkConnection.on("events", events => {
console.log("**********business event received**********", events);
});
})
// and catch any exceptions that are triggered
.catch(function(error) {
throw error;
});
I see data returned after the connection has been made in the result object and it is the correct network data that has been deployed.
However, when I submit transactions and made request VIA my generated REST APIs no events are seen by my server. In the Historian, I can see that events are emitted. Is there something else that I should be doing to see those events emitted by my transactions?
I tried same kind of test and I could receive events. I compared my test code and yours, and I found following difference:
this.bizNetworkConnection.on('events'
this.bizNetworkConnection.on('event'
I hope it helps.
I was watching Steve Sanderson's NDC presentation on up-and-coming web features, and saw his caching example as a prime candidate for an application I am developing. I couldn't find the code, so I have typed it up off the Youtube video as well as I could.
Unfortunately it doesn't work in Chrome (which is also what he is using in the demo) It fails with Uncaught TypeError: fetch(...).then(...).timeout is not a function
at self.addEventListener.event.
I trawled through Steve's Github, and found no trace of this, nor could I find anything on the NDC Conference page
//inspiration:
// https://www.youtube.com/watch?v=MiLAE6HMr10
//self.importScripts('scripts/util.js');
console.log('Service Worker script running');
self.addEventListener('install', event => {
console.log('WORKER: installing');
const urlsToCache = ['/ServiceWorkerExperiment/', '/ServiceWorkerExperiment/scripts/page.js'];
caches.delete('mycache');
event.waitUntil(
caches.open('mycache')
.then(cache => cache.addAll(urlsToCache))
.then(_ => self.skipWaiting())
);
});
self.addEventListener('fetch', event => {
console.log(`WORKER: Intercepted request for ${event.request.url}`);
if (event.request.method !== 'GET') {
return;
}
event.respondWith(
fetch(event.request)
.then(networkResponse => {
console.log(`WORKER: Updating cached data for ${event.request.url}`);
var responseClone = networkResponse.clone();
caches.open('mycache').then(cache => cache.put(event.request, responseClone));
return networkResponse;
})
//if network fails or is too slow, return cached data
//reference for this code: https://youtu.be/MiLAE6HMr10?t=1003
.timeout(200)
.catch(_ => {
console.log(`WORKER: Serving ${event.request.url} from CACHE`);
return caches.match(event.request);
})
);
});
As far as I read the fetch() documentation, there is no timeout function, so my assumption is that the timeout function is added in the util.js which is never shown in the presentation... can anyone confirm this? and does anyone have an Idea about how this is implemented?
Future:
It's coming.
According to Jake Archibald's comment on whatwg/fetch the future syntax will be:
Using the abort syntax, you'll be able to do:
const controller = new AbortController();
const signal = controller.signal;
const fetchPromise = fetch(url, {signal});
// 5 second timeout:
const timeoutId = setTimeout(() => controller.abort(), 5000);
const response = await fetchPromise;
// …
If you only wanted to timeout the request, not the response, add:
clearTimeout(timeoutId);
// …
And from another comment:
Edge & Firefox are already implementing. Chrome will start shortly.
Now:
If you want to try the solution that works now, the most sensible way is to use this module.
It allows you to use syntax like:
return fetch('/path', {timeout: 500}).then(function() {
// successful fetch
}).catch(function(error) {
// network request failed / timeout
})