Add index map support

src/index.html

@@ -54,6 +54,11 @@
       >
         Sanborn (Scanned Map, COG)
       </button>
+      <button
+        data-record-url="https://raw.githubusercontent.com/OpenGeoMetadata/edu.stanford.purl/b74664cbb36fb985fe2ebee8d0d6d9657f06ada1/metadata-aardvark/zy/089/tj/2215/geoblacklight.json"
+      >
+        Peatland (Index Map, OpenIndexMaps/GeoJSON)
+      </button>
     </div>
     <ogm-viewer></ogm-viewer>
   </body>

src/utils/references.ts

@@ -69,6 +69,10 @@ export class References {
     return this.references['https://github.com/cogeotiff/cog-spec'];
   }
 
+  get indexMap() {
+    return this.references['https://openindexmaps.org'];
+  }
+
   // List of download links with URL and label
   get downloadLinks(): LabelledLinks {
     const fieldContents = this.references['http://schema.org/downloadUrl'];

src/utils/sources.ts

@@ -15,8 +15,8 @@ export const getPreviewLayer = (record: OgmRecord): AddLayerObject => {
 
 // Map source types to layer types using information from the record
 const getLayerType = (_record: OgmRecord, source: SourceSpecification): LayerType => {
-  // For now, we only support raster layers
   if (source.type === 'raster') return 'raster';
+  else if (source.type === 'geojson') return 'fill';
   else throw new Error(`Unsupported source type: ${source.type}`);
 };
 
@@ -26,6 +26,7 @@ const getRecordSource = (record: OgmRecord): AddSourceObject => {
     // Methods that create new sources are added here in order of preference
     // The first one that returns a valid source will be used
     recordCOGSource(record),
+    recordOpenIndexMapsSource(record),
     recordWMSSource(record),
   ].find(Boolean);
 };
@@ -99,3 +100,17 @@ const createWMSSource = ({
     attribution,
   };
 };
+
+const recordOpenIndexMapsSource = (record: OgmRecord): AddSourceObject => {
+  const indexMapUrl = record.references.indexMap;
+  if (!indexMapUrl) return null;
+
+  return {
+    id: record.id,
+    source: {
+      type: 'geojson',
+      data: indexMapUrl,
+      attribution: record.attribution,
+    },
+  };
+};