add featureserver

Author: smohiudd

README.md

@@ -137,6 +137,18 @@ Links to a [TileJSON](https://github.com/mapbox/tilejson-spec) document.
 | href       | string | **REQUIRED**. Link to the valid TileJSON document. |
 | type       | string | Recommended to be set to `application/json`. |
 
+### FeatureServer
+
+Links to a [ArcGIS FeatureServer](https://developers.arcgis.com/rest/services-reference/enterprise/query-feature-service-layer/) service. 
+
+| Field Name      | Type                 | Description |
+| --------------- | -------------------- | ----------- |
+| rel             | string               | **REQUIRED**. Must be set to `featureserver`. |
+| href            | string               | **REQUIRED**. Link to a FeatureServer service. Usually has the following form `https://<root>/<serviceName>/FeatureServer`|
+| type            | string               | Recommended to be set to `application/json` |
+| featureserver:layers  | Map<string, string> | Layers |
+
+
 ### General
 
 The following field applies to multiple types of web mapping services:

examples/collection.json

@@ -95,6 +95,15 @@
       "pmtiles:layers": [
         "streets"
       ]
+    },
+    {
+      "href": "https://service.arcgis.com/arcgis/rest/datast/FeatureServer",
+      "rel": "featureserver",
+      "title": "ArcGIS FeatureServer",
+      "type": "application/json",
+      "featureserver:layers": {
+        "0": "streets"
+      }
     }
   ]
 }

json-schema/schema.json

@@ -165,6 +165,31 @@
                 }
               }
             }
+          },
+          {
+            "$comment": "Defines FeatureServer links",
+            "if": {
+              "properties": {
+                "rel": {
+                  "const": "featureserver"
+                }
+              }
+            },
+            "then": {
+              "properties": {
+                "pmtiles:layers": {
+                  "type": "object",
+                  "items": {
+                    "type": "string",
+                    "minItems": 1,
+                    "items": {
+                      "type": "string",
+                      "minLength": 1
+                    }
+                  }
+                }
+              }
+            }
           }
         ]
       }