Get nearest users within a circle by current location node js

Question

I'm explaining with an example to achieve my result.

I have a users table. Each user has their location with latitude and longitude on the database. I'm using firebase database. So the DB looks like:

users {
  user-id{
     location{
        latitude
        longitude
     }
  }
}

I need to find users within a circle using my current location.

I've looked into geolib and found a method isPointInCircle . But using this, we need to iterate users data and needs to call this method on each loop. I need to avoid this multiple calls and achieve with only one method call like:

findNearestUsers(currentLocation,userLocations);

The result should be an array having nearest locations. How can I do this? Thanks in advance :)

yes, I've looked into this one. But I cannot find any logic about my requirement — Manu MT, Nov 10 '17 at 09:01
As a side note, the new Firestore should implement geo queries eventually... — cutiko, Nov 16 '17 at 12:32

score 2 · Accepted Answer · answered Nov 10 '17 at 13:19

GeoFire is the only way to query the Firebase Realtime Database based on proximity to a specific point, without having to download all data and filtering client side.

With GeoFire you create a GeoQuery for a location and a maximum distance:

var geoQuery = geoFire.query({
  center: [10.38, 2.41],
  radius: 10.5
});

You then attach handlers for items that fall within this range:

var onKeyEnteredRegistration = geoQuery.on("key_entered", function(key, location, distance) {
  console.log(key + " entered query at " + location + " (" + distance + " km from center)");
});

There is no built-in functionality for finding a single, closest item. You could do that client-side based on the distance parameter in the callback. You'd still be retrieving more data than needed, but hopefully it'd be less than the entire database.

Sorry for my late reply. Thank you for your reply. Let me do with this — Manu MT, Nov 15 '17 at 06:29

score 0 · Answer 2 · answered Nov 10 '17 at 08:22

0

There is no way to index and query the Firebase realtime database without getting the whole dataset and process locally.

I suggest switching to the new released beta Cloud Firestore instead which even has a geopoint as a data type and better support for sql-like "where queries".
Cloud Firestore queries

answered Nov 10 '17 at 08:22

DaSe

64
5

Thanks for the suggestion. But I cannot try on my current project. Because almost done using firebase. I would try on my next project. Instead of the database can you suggest anything for the geolocation functionality? – Manu MT Nov 10 '17 at 08:58
While Firestore supports geo-data, it does [not currently support geo-queries](https://stackoverflow.com/a/46608540). There **is** a fine way to accomplish the same on the Firebase Realtime Database, it's a library called GeoFire. If you need geo-query support today today, that is the [recommended route](https://stackoverflow.com/a/46554998). – Frank van Puffelen Nov 10 '17 at 13:13

Get nearest users within a circle by current location node js

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