Check if a user's location is within a defined area (geo polygon)

Hey there! In this guide, we'll walk through how to use Xano's no-code platform to build a location-based service that checks if a user is within a defined service area. Let's get started!

Step 1: Create a Database Table

First, we need to create a database table to store our service areas. Here's how:

1. In Xano, go to the "Database" section and click "Add Table".
2. Name the table "Area".
3. Add two fields:

• "Name" (type: Text) - for the name of the service area
• "Area" (type: Polygon) - for the geographic polygon that defines the service area

For example, let's create a service area called "Service Area 1" with a polygon around a popular restaurant near your location, such as Firestone Grill.

Step 2: Create an API Endpoint

Next, we'll create an API endpoint to check if a user's location is within the defined service area:

1. Go to the "API" section and click "Add Endpoint".
2. Select the "Get Area" endpoint.
3. Add an input field of type "Point" called "User Location". This will represent the user's geographic coordinates, typically obtained from their device.

Step 3: Filter the Query

Now, we need to filter the query to return the service area only if the user is within its boundaries:

1. In the "Get Area" endpoint, click on the "Query All Records" function.
2. Switch to the "Custom Query" mode by clicking the pencil icon.
3. Add a conditional filter:

• Reference the "Area" table and the "Area" field.
• Use the "within" filter condition.
• Set the input to the "User Location" field you created earlier.
• Set an offset distance (e.g., 10 meters) to define the proximity range.

1. In the "within" evaluation, set the value to "true" to ensure the query returns results only if the user is within the defined area.
2. Save the changes.

Step 4: Test the Service

To test the location-based service:

1. In the "Get Area" endpoint, click "Run".
2. If no "User Location" is provided, the query will not return any results.
3. Copy and paste a set of longitude and latitude coordinates that fall within the defined service area polygon (e.g., around Firestone Grill).
4. Run the endpoint again with the provided coordinates.

If the user's location is within the specified service area (plus the offset distance), the query will return the corresponding service area details.

And that's it! You've successfully built a location-based service using Xano's no-code platform. You can now integrate this service into your web or mobile applications, providing location-based functionality without writing any code.

Remember, Xano is designed to simplify backend development, making it accessible to both non-technical users and experienced developers alike. Whether you're a no-code enthusiast, citizen developer, traditional developer, or part of a startup or small business, Xano can help you build and deploy applications more efficiently.