How to notify nearby users within a certain location
<p>I've been thinking about this and I couldn't figure it out on how to develop this feature. Currently my app will technically notify every driver, whenever another user trigger a button. I'm using google Maps for calculating routes and so on.</p>

<p>The feature that I'm building is similar like Uber notification system, where whenever a user click "set pickup location" it will then notify to bunch of drivers nearby the user's location.</p>

<p>But the problem right now, it will notify to every drivers that is online, and that's not what I want. I want to notify only the drivers that are nearby to the user's location.</p>

<p>How would I achieve this? What sorts of variables do i need to accomplish this</p>

<p>Im using</p>

<ul>
<li>IOS/Swift</li>
<li>Google maps</li>
<li>node.js as the backend and socket.io as realtime</li>
</ul>