I have the following code
//index.js
export const deletePicture = functions.region("europe-west1").database
.ref("galleries/{galleryId}/{pictureId}")
.onDelete(pictures.deletePicture)
//pictures.js
export const deletePicture = (snap, {params: {galleryId}}) => {
console.log("Image deletion detected in the database, deleting images
from the Storage...")
const {fileName} = snap.val()
const bucket = storage.bucket()
const baseURL = `galleries/${galleryId}`
// Thumbnails
const promises = [sizes
.map(size =>
bucket.file(`${baseURL}/thumb_${size}_${fileName}`).delete())]
// Original
promises.push(bucket.file(`${baseURL}/${fileName}`).delete())
return Promise
.all(promises)
.then(() => console.log(`All versions of ${fileName} are now deleted.`))
}
In my realtime database and Storage, I have the following structure:
galleries
|_rooms
| |_roomId
| |_picture
|_foods
|_picture
Is there any way that the above mentioned onDelete Cloud Function would trigger for the deletion of either of the pictures? The difference here is that the rooms picture is one level deeper, so I think that pictureId does not match roomId/picture.
Cloud Functions has no knowledge of the meaning of your JSON. So the trigger for delete of galleries/{galleryId}/{pictureId}, really just means that this function gets triggered whenever a node at the second level under galleries gets trigged.
In the structure you show, that means that this function will trigger whenever /galleries/room/roomId or /galleries/foods/picture gets deleted. The first of these will get triggered when you delete the last picture from a room.
Related
Im trying to run a cron job to delete old notifications. Following a post on this on medium:
https://medium.com/#varunpvp/how-to-schedule-a-firebase-cloud-function-ded2db0cf9f3
This is where im up to:
const oneMonthOld = admin.firestore.Timestamp.now().toMillis() - 2592000000;
const oldNotifications = await admin.firestore()
.collection('notifications')
.where('createdAt', '>', oneMonthOld);
I've created a document in this collection. I have other queries in the function working against this collection. The article sais that more than is < (?) i've tried both ways round
const results2 = await oldNotifications.get();
results2.forEach(doc => {
console.log('in function');
oldNotificationsBatch.delete(doc.ref);
});
the function neither deletes the record or emits the log in the UI
Can anyone suggested whats going wrong here?
I have a database with a bunch of dates and an online overview where you can view them, now I know I can copy a URL from my Google Agenda and import this in other calendar clients so I can view the events there.
I want to generate an Express endpoint where I fetch every event every time the endpoint is called and return it in a format that can be imported by other calendar clients. Now with packages like iCal-generator I could generate, read, and return the file whenever a user requests the URL. but it feels redudent to write a file to my storage to then read it, return it and delete it every time it's requested.
What is the most effiecent way to go about this?
Instead of generating the file/calendar data on every request, you could implement a simple caching mechanism. That is, upon start of your node app you generate the calendar data and put it in your cache with corresponding time to live value. Once the data has expired or new entries are inserted into your DB you invalidate the cache, re-generate the data and cache it again.
Here's a very simple example for an in-memory cache that uses the node-cache library:
const NodeCache = require('node-cache');
const cacheService = new NodeCache();
// ...
const calendarDataCacheKey = 'calender-data';
// at the start of your app, generate the calendar data and cache it with a ttl of 30 min
cacheCalendarData(generateCalendarData());
function cacheCalendarData (calendarData) {
cacheService.set(calendarDataCacheKey, calendarData, 1800);
}
// in your express handler first try to get the value from the cache
// if not - generate it and cache it
app.get('/calendar-data', (req, res) => {
let calendarData = cacheService.get(calendarDataCacheKey);
if (calendarData === undefined) {
calendarData = generateCalendarData();
cacheCalendarData(calendarData);
}
res.send(calendarData);
});
If your app is scaled horizontally you should consider using redis.
100% untested, but I have code similar to this that exports to a .csv from a db query, and it might get you close:
const { Readable } = require('stream');
async function getCalendar(req, res) {
const events = await db.getCalendarEvents();
const filename = 'some_file.ics';
res.set({
'Content-Type': 'text/calendar',
'Content-Disposition': `attachment; filename=${filename}`,
});
const input = new Readable({ objectMode: true });
input.pipe(res)
.on('error', (err) => {
console.error('SOME ERROR', err);
res.status(500).end();
});
events.forEach(e => input.push(e));
input.push(null);
}
if you were going to use the iCal generator package, you would do your transforms within the forEach method before pushing to the stream.
I need to write a lambda function and send a number in the api request field to genrate the number of QR codes and store them in a S3 bucket.I am using the serverless framework with the aws-nodejs template.
To describe the task briefly lets say I get a number input in the api request PathParameters and based on these number I have to generate those number of QR's using the qr npm package and then store these generated qr's in the s3 bucket
this is what i have been able to do so far.
module.exports.CreateQR = (event,context) =>{
const numberOfQR = JSON.parse(event.pathParameters.number) ;
for(let i=0;i<numberOfQR;i++){
var d= new Date();
async function createQr(){
let unique, cipher, raw, qrbase64;
unique = randomize('0', 16);
cipher = key.encrypt(unique);
raw = { 'version': '1.0', data: cipher, type: 'EC_LOAD'}
// linkArray.forEach( async (element,index) =>{
let qrcode = await qr.toDataURL(JSON.stringify(raw));
console.log(qrcode);
// fs.writeFileSync('./qr.html', `<img src="${qrcode}">`)
const params = {
Bucket:BUCKET_NAME,
Key:`QR/${d}/img${i+1}.jpg`,
Body: qrcode
};
s3.upload(params , function(err,data){
if(err){
throw err
}
console.log(`File uploaded Successfully .${data.Location}`);
});
}
createQr();
}
};
I have been able to upload a given number of images to the bucket but the issue i am facing is the images are not going in the order.I think the problem is with the asynchronous code. Any idea how to solve this issue
that's because you're not awaiting the s3 to upload, but instead you have a callback.
you should use the .promise of s3 and then await it, so you'll wait the file to be uploaded before move to the next one
I changed the example of code
See docs:
https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#upload-property
https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3/ManagedUpload.html#promise-property
// see the async keyword before the lambda function
// we need it for use the await keyword and wait for a task to complete before continue
module.exports.CreateQR = async (event,context) =>{
const numberOfQR = JSON.parse(event.pathParameters.number) ;
// moved your function out of the loop
function createQr(){
// ...
// here we call .promise and return it so we get a Task back from s3
return s3.upload(params).promise();
}
for(let i=0;i<numberOfQR;i++){
// ....
// here we await for the task, so you will get the images being created and uploaded in order
await createQr();
}
};
hope it guide you towards a solution.
I am developing an app and trying to implement news feed by getstream.io using react native and firebase.
Is there a way to generate user token by using firebase cloud function. If there is, would you please give me a pointer how i can do so? (the snippet of codes in cloud function side and client side would be super helpful..)
I have seen similar questions, only to find out no specific tutorial.. any help is appreciated!
For the cloud function side you need to create a https.onRequest endpoint that calls createUserToken like so:
const functions = require('firebase-functions');
const stream = require('getstream');
const client = stream.connect('YOUR_STREAM_KEY', 'YOUR_STREAM_SECRET', 'YOUR_STREAM_ID');
exports.getStreamToken = functions.https.onRequest((req, res) => {
const token = client.createUserToken(req.body.userId);
return { token };
});
After that, deploy with firebase deploy --only functions in the terminal & get the url for the function from your firebase dashboard.
Then you can use the url in a POST request with axios or fetch or whatever like this:
const { data } = axios({
data: {
userId: 'lukesmetham', // Pass the user id for the user you want to generate the token for here.
},
method: 'POST',
url: 'CLOUD_FUNC_URL_HERE',
});
Now, data.token will be the returned stream token and you can save it to AsyncStorage or wherever you want to store it. Are you keeping your user data in firebase/firestore or stream itself? With a bit more background I can add to the above code for you depending on your setup! 😊 Hopefully this helps!
UPDATE:
const functions = require('firebase-functions');
const stream = require('getstream');
const client = stream.connect('YOUR_STREAM_KEY', 'YOUR_STREAM_SECRET', 'YOUR_STREAM_ID');
// The onCreate listener will listen to any NEW documents created
// in the user collection and will only run when it is created for the first time.
// We then use the {userId} wildcard (you can call this whatever you like.) Which will
// be filled with the document's key at runtime through the context object below.
exports.onCreateUser = functions.firestore.document('user/{userId}').onCreate((snapshot, context) => {
// Snapshot is the newly created user data.
const { avatar, email, name } = snapshot.val();
const { userId } = context.params; // this is the wildcard from the document param above.
// you can then pass this to the createUserToken function
// and do whatever you like with it from here
const streamToken = client.createUserToken(userId);
});
Let me know if that needs clearing up, these docs are super helpful for this topic too 😊
https://firebase.google.com/docs/functions/firestore-events
Let's say my app has a collection for every restaurant that uses it. Each document for each collection is basically a type of food that has an expiration time stamp on it. What I need to do it query through every 'food' in every 'restaurant' and delete each 'food' if the current time that I get from my node js server is past the expiration time stamp. What is an efficient way to do this?
First you need a HTTP Request trigger Cloud Function that you can invoke by cron. ie. https://cron-job.org/
With this cloud function you should use the Admin JS SDK to loop through collections and fetch all documents.
You can get all collections with the function getCollections() See https://cloud.google.com/nodejs/docs/reference/firestore/0.9.x/Firestore#getCollections
import * as admin from 'firebase-admin'
try {
admin.initializeApp(functions.config().firebase)
} catch (e) {}
const db = admin.firestore()
export const getCollections = functions.https.onRequest(async(req, res) => {
const collections = await db.getCollections()
res.status(200).send(collections.map(collection => collection.id))
})