don't require nextzen API key if serving locally

Makefile

@@ -4,5 +4,8 @@ cli:
 debug:
 	go run -mod vendor cmd/server/main.go -nextzen-apikey $(APIKEY) -enable-placeholder -placeholder-endpoint $(SEARCH) -enable-oembed -oembed-endpoints 'https://millsfield.sfomuseum.org/oembed/?url={url}&format=json' -enable-writer
 
+debug-tilepack:
+	go run -mod vendor cmd/server/main.go -enable-tilezen-tilepacks -tilezen-path-tilepack $(TILEPACK) -nextzen-tile-url 'http://localhost:8080/tilezen/vector/v1/512/all/{z}/{x}/{y}.mvt' -enable-oembed -oembed-endpoints 'https://millsfield.sfomuseum.org/oembed/?url={url}&format=json' -enable-writer
+
 debug-protomaps:
 	go run -mod vendor cmd/server/main.go -map-renderer protomaps -protomaps-tile-url $(TILES) -enable-oembed -oembed-endpoints 'https://millsfield.sfomuseum.org/oembed/?url={url}&format=json' -enable-writer -writer-uri exif://

app/flags.go

@@ -133,7 +133,7 @@ func AppendTilezenFlags(fs *flag.FlagSet) error {
 
 	fs.Bool("enable-tilezen-tilepacks", false, "Enable to use of local Tilezen MBTiles database.")
 	fs.String("tilezen-path-tilepack", "", "A valid path for a local Tilezen MBTiles database.")
-	fs.String("tilezen-url-tiles", "/tilezen", "The URL (a relative path) for serving local Tilezen MBTiles database.")
+	fs.String("tilezen-url-tiles", "/tilezen/", "The URL (a relative path) for serving local Tilezen MBTiles database.")
 
 	// https://github.com/sfomuseum/go-http-tilezen
 

static/javascript/geotag.maps.js

@@ -93,17 +93,32 @@ geotag.maps = (function(){
 	    }
 
 	    if (map_renderer == "tangramjs"){
+
+		// If we don't have an API key check to see if we're serving tiles locally
 
 		if (! args["api_key"]){
-		    return null;
+
+		    var tile_url = args["tile_url"];
+
+		    var proto = location.protocol;
+		    var host = location.host;
+		    var test = proto + "//" + host;
+
+		    if (! tile_url.startsWith(test)){
+			console.log("Missing Nextzen API key and tile URL is not local server");
+			return null;
+		    }
+
+		    // Tangram.js expects an API key even if it's bunk
+		    args["api_key"] = "local";
 		}
 
-		var api_key = args["api_key"];
-
 		var tangram_opts = self.getTangramOptions(args);	   
 		var tangramLayer = Tangram.leafletLayer(tangram_opts);
 
 		tangramLayer.addTo(map);
+
+		map.setMaxZoom(17);	// really?
 	    }
 
 	    var attribution = self.getAttribution(map_renderer);
@@ -144,7 +159,7 @@ geotag.maps = (function(){
 			    url_subdomains: ['a', 'b', 'c', 'd'],
 			    url_params: {api_key: api_key},
 			    tile_size: 512,
-			    max_zoom: 18
+			    max_zoom: 18, 
 			}
 		    }
 		}