Using ArcGIS REST Service to query particular features inside BBOX?

Digging into Data: Querying Features Inside a Bounding Box with ArcGIS REST Services

ArcGIS REST Services? Yeah, they might sound a bit intimidating, but trust me, they’re your gateway to some seriously cool geographic data on the web. Think of them as a way to tap into maps and spatial info, letting you grab just what you need. And one of the handiest tricks in the book is querying for features inside a specific area – what we GIS folks call a bounding box, or BBOX.

So, what’s the big deal? Well, imagine you’re building an app that shows all the coffee shops in a particular neighborhood. A BBOX query lets you quickly filter out the noise and focus on just the coffee goodness within that area.

Let’s break it down. An ArcGIS REST Service basically serves up geographic data like a restaurant serves food – you make a request, and it dishes out the data. These services let you ask for data in different flavors, like JSON (which is super common for web stuff), and do all sorts of things, from simple queries to complex spatial analyses. The bounding box query? That’s your bread and butter for grabbing features within a rectangular area you define.

Think of a bounding box as a digital rectangle drawn on a map. You define it using the coordinates of its corners: the westernmost (minX), southernmost (minY), easternmost (maxX), and northernmost (maxY) points. String those together with commas, and you’ve got your BBOX: minX, minY, maxX, maxY. For example, -122.4,37.7,-122.3,37.8 – that’s a chunk of San Francisco.

Crafting Your Query: It’s All About the URL

To get the data you want, you’ll construct a URL that tells the service exactly what you’re after. It’s like ordering at that data restaurant. The main course is the service’s “query” endpoint, and you add parameters to specify your order. Here’s the basic recipe:

Service URL/query?parameter1=value1&parameter2=value2…

The geometry parameter is where the magic happens. This tells the service, “Hey, I only want stuff within this shape.” You also need to tell it that the shape is a bounding box by setting geometryType to esriGeometryEnvelope. And to specify how the bounding box relates to the features you’re querying, you’ll use the spatialRel parameter. “Intersects” (esriSpatialRelIntersects) is your go-to here – it grabs anything that touches or crosses your BBOX.

Let’s recap the key ingredients:

• geometry: Your bounding box coordinates, like -122.4,37.7,-122.3,37.8.
• geometryType: Always esriGeometryEnvelope for bounding boxes.
• spatialRel: Usually esriSpatialRelIntersects. But you could also use esriSpatialRelContains (for features completely inside the BBOX) or esriSpatialRelWithin (for features that completely surround the BBOX).
• inSR: The coordinate system of your BBOX. 4326 is the code for WGS 84 (good old latitude-longitude).
• outFields: Which fields you want back. * means “give me everything!”
• returnGeometry: Set to true to get the actual shapes of the features.
• f: The output format. json is your friend.

Putting It All Together: A Real-World Example

Okay, let’s say you’ve got an ArcGIS REST Service hanging out at https://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/0. You want to find cities near that San Francisco BBOX we mentioned earlier. Here’s what your query URL would look like:

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