How do I match geolocation to other app user in the vicinity?

[Rr Projects]

Hi there,

I am new at Appery and app development and am trying to figure out how to build an app that uses the users location and seeks for other users in a x mile/km radius. The users location may vary and is determined by GPS from the device.

I searched the net and watched various videos on geolocation but I can't quite find anything on this topic. Please can you share with me some pointers, info, websites and/or videos if available?

Thanks!

Rira

[Bruce Stuart]

Hello Rira,

I'm assuming that you plan on updating a database table with each users geolocation with some frequency when they are logged in ....

You can and likely should store thei geolocation in a database field with type of 'geopoint' .... Google MongoDb geopoint data type' for a little more on this.

You client app can then Query the db geopoint field for users within a radius of their location. It's a built in feature of Mongodb which Appery uses on the backend.

If you'd like a sample query that does this ... Let me know I'll post it here. Do a quick -15 minute read on a geopoint query first to get the general idea ...

Best,

Bruce

[Yurii Orishchuk]

Hi Rira,

Here is a brief plan for it:

1. Get current user position with geolocation service.
   Details: http://devcenter.appery.io/tutorials/...

2. Make geospatial query to DB.
   Details are here: http://devcenter.appery.io/documentat...

   Also you should use geopoint field for the collection of your users to make query.

   Bruce thanks for this explanation.

   Regards.

[Bruce Buttles]

Bummer, the link in your bullet #2 does not take you to anything that helps. Can you send me the link to the "Make geospatial query to DB" examples?

[Bruce Buttles]

Okay - we will continue the dialog here.
Where can I find good examples of making a geospatial query to the DB using a geopoint column?

[Serhii Kulibaba]

Hello Bruce,

Please look at this documentation: https://devcenter.appery.io/documenta...

[Raj K]

Can the geolocation service be used to find two users/devices that are in a very close proximity like 10 feet or less?

Thanks,
Kiran

[Illya Stepanov]

Hello Kiran,

The Geolocation service is reading coordinates of the device on which it runs, if you need to read coordinates of another device then you'll need to use transmitter-receiver approach on both devices. In Appery.io apps this can only be implemented with Cordova plugin functionality.

[Bruce Stuart]

Kiran,

Illya is correct literally.

If however you were to have both devices logging their locations to a Appery database, you could have the devices on the impacted devices doing Geospatial queries to find other users within a given distance.

However, 10 feet or less is an extremely low 'accuracy' - and most geolocation readings coming from your phone do not give an accuracy of within 10 yards.... 30-50 feet is a more likely goal.

Also - unless you are using background GeoLocation (there are plugins that do this) the users would have to be active in the app - in order for this approach to work. (Your app will not receive location information once it has become 'backgrounded' - generally 1-3 minutes of in-activity unless you use the plugin approach).

Keep in mind - The background geolocation approach is is 'high end' and requires some experience to code and manage.

Best,
Bruce