How to orderby/sort incoming data from Firebase - node.js

Question

I'm working on a firebase and node.js Express project which is basically an ordering system.
I want to sort my incoming order by time. I've tried using the Orderby() function that firebase provide but it still messes up the order in the json output.
It seems that this should work and i didn't have to sort it in afterwards on my frontend
This is my get route for the firebase
// route for database
router.get("/orderslist", (req, res) => {
let orders = []
let number_of_orders
// Getting the snapshot of the order collection
db.collection('orders').orderBy('time').get().then( productSnapshot => {
number_of_orders = productSnapshot.size
// iterating over the order snapshot
productSnapshot.forEach(orderDoc => {
// creating an order object and assigning the ID and the rest of the information from the database
var order = {
id: orderDoc.id,
customer_name: orderDoc.data().customer_name,
date: orderDoc.data().date,
comments: orderDoc.data().comments,
time: orderDoc.data().time,
total: orderDoc.data().total,
order_status: orderDoc.data().order_status,
products: []
}
// using the id, to get the products from the subcollection
db.collection('orders/' + order.id + '/products').get().then( productSnapshot => {
// iterating over the product snapshot
productSnapshot.forEach(productDoc => {
// creating a product object
var product = {
name: productDoc.data().name,
price: productDoc.data().price
}
// then we push the product object to the list of products in the order object
order.products.push(product)
});
// we are finished iterating over the productsnapshot and now we can push it to the orders list
orders.push(order)
// checks if the list is filled with everything from the database
if(orders.length == number_of_orders){
return res.json(orders)
}
});
});
});
});
This is the data in json
[
{
"id": "xWmlB9fHD4rw8Di75llp",
"customer_name": "Emil",
"date": "07/05-2020",
"comments": "without sugar",
"time": "a",
"total": 40,
"order_status": true,
"products": [
{
"name": "Latte",
"price": 40
}
]
},
{
"id": "GWJoxe0DVFDWfi2AW6jS",
"customer_name": "test",
"date": "222222",
"comments": "",
"time": "f",
"total": 10,
"order_status": false,
"products": [
{}
]
},
{
"id": "ggYSVKA1i0U8khIpeud4",
"customer_name": "Oliver",
"date": "01/05-2020",
"comments": "order to be packed neatly because im on a bike",
"time": "d",
"total": 38,
"order_status": false,
"products": [
{
"name": "Latte Macchiato",
"price": 38
}
]
}
]

Answer 1

I recommend that you create a proper Firestore timestamp field to be used as a reference not the string field you have called "time".
With that being said, knowing Firestore timestamps can be tricky, here's how you can use them.
When you get timestamps from Firestore they are of the following type:
To convert this into a normal timestamp you can use the .toDate() function.
For example, for a document like the following:
We can use something like:
db.collection('[COLLECTION]').doc('[DOCUMENT]').get().then(function(doc) {
console.log(doc.data().[FIELD].toDate());
});
and the output will be like:
2019-12-16T16:27:33.031Z
Now to process that timestamp further, you can convert it into a string and use regex to modify it according to your needs.
For example: (I'm using Node.js here)
db.collection('[COLLECTION]').doc('[DOCUMENT]').get().then(function(doc) {
var stringified = doc.data().[FIELD].toDate().toISOString();
//console.log(stringified);
var split1 = stringified.split('T');
var date = split1[0].replace(/\-/g, ' ');
console.log(date);
var time = split1[1].split('.');
console.log(time[0]);
});
Will give you an output like this:
Now you can use the orderby approach on the query itself or once you fetch them in your frontend.
An example orderby is the following:
db.collection('[COLLECTION]')
.orderBy("timeStamp", Query.Direction.ASCENDING)
However, if you plan to keep using the string type you have there (not recommended), you will have to convert that string to a numeric value (possible ASCII) to be able to filter on that properly as a time object.