How can I implement radius-based location filtering in my app?

To implement radius filtering, you'll mainly rely on latitude and longitude calculations. When a user enters an address, convert that into latitude and longitude coordinates using a geocoding service. Then, for radius searching, you can use the Haversine formula to calculate the distance between points based on those coordinates. It’s pretty straightforward! Look it up for more details.

A practical approach is to convert the user's search location into latitude and longitude and then run a query to find all addresses within the defined distance. You can set up a bounding box using this formula: X - distance, X + distance, Y - distance, Y + distance. This will give you a box of potential matches, and then you can calculate the exact distance and filter out any that don’t meet the radius requirement. It's not the most efficient method but can work well if your database doesn't support geospatial queries.

If you're using PostgreSQL, consider utilizing its PostGIS extension for geospatial queries. It makes filtering by radius easier, and you'll definitely want to store latitude and longitude coordinates in your database. When users search, convert their input into coordinates and perform your query based on those. Also, using APIs like Google Maps can help with geocoding addresses to their respective coordinates.