ENH: Update interactive map preview

CHANGELOG.md

@@ -2,10 +2,19 @@
 
 ## 0.10.0 (in development)
 
--   now requires Go 1.18+.
 -   supports GCC11 on Ubuntu 22.04 (#166)
 -   switch from Docker Hub to Github Container Registry (#168)
 
+### Breaking changes
+
+-   now requires Go 1.18+.
+-   replaced Leaflet and Mapbox GL JS maps used in preview endpoint with MapLibre GL.
+    This change drops the interactive map controls present in the Leaflet preview
+    (opacity slider, basemap changer, zoombox) (#176).
+-   removed built-in basemaps used in the preview endpoint (#176).  You can now
+    specify a basemap style using the `--basemap-style-url` option or basemap
+    image tiles using the `--basemap-tiles-url` option.
+
 ## 0.9.0
 
 ### Breaking changes

README.md

@@ -356,7 +356,42 @@ returns something like this:
 
 `mbtileserver` automatically creates a map preview page for each tileset at `/services/<tileset_id>/map`.
 
-This currently uses `Leaflet` for image tiles and `Mapbox GL JS` for vector tiles.
+It uses `MapLibre GL` to render vector and image tiles.
+
+No built-in basemap is included by default in the map preview.  You can use
+one of the following options to include a basemap.
+
+### Basemap style URL
+
+To include a [MapLibre GL style URL](https://maplibre.org/maplibre-style-spec/)
+use the `--basemap-style-url` option to provide a URL to that style:
+
+```
+--basemap-style-url "https://tiles.stadiamaps.com/styles/stamen_toner_lite.json?api_key=<your key>
+```
+
+The URL can include query parameters as required by the host, such as
+`?access_token=<something>`.
+
+
+### Basemap tiles URL
+
+To include a basemap based on image tile URLs, use the `--basemap-tiles-url`
+option to provide a raster tile URL pattern:
+
+```
+--basemap https://some.host/{z}/{x}/{y}.png
+```
+
+The template parameters `{z}` (zoom), `{x}`, `{y}` are required.
+
+The extension can be omitted or be any image format supported by MapLibre GL.
+
+The URL can include query parameters as required by the host, such as
+`?access_token=<something>`.
+
+IMPORTANT: this does not support vector tiles.
+
 
 ## ArcGIS API
 

handlers/serviceset.go

@@ -17,6 +17,8 @@ type ServiceSetConfig struct {
 	EnableTileJSON    bool
 	EnablePreview     bool
 	EnableArcGIS      bool
+	BasemapStyleURL   string
+	BasemapTilesURL   string
 	RootURL           *url.URL
 	ErrorWriter       io.Writer
 }
@@ -30,8 +32,9 @@ type ServiceSet struct {
 	enableTileJSON    bool
 	enablePreview     bool
 	enableArcGIS      bool
+	basemapStyleURL   string
+	basemapTilesURL   string
 
-	domain      string
 	rootURL     *url.URL
 	errorWriter io.Writer
 }
@@ -50,6 +53,8 @@ func New(cfg *ServiceSetConfig) (*ServiceSet, error) {
 		enableTileJSON:    cfg.EnableTileJSON,
 		enablePreview:     cfg.EnablePreview,
 		enableArcGIS:      cfg.EnableArcGIS,
+		basemapStyleURL:   cfg.BasemapStyleURL,
+		basemapTilesURL:   cfg.BasemapTilesURL,
 		rootURL:           cfg.RootURL,
 		errorWriter:       cfg.ErrorWriter,
 	}

handlers/templates.go

@@ -23,7 +23,7 @@ func init() {
 		panic(err)
 	}
 
-	t, err := template.ParseFS(templatesFS, "map.html", "map_gl.html")
+	t, err := template.ParseFS(templatesFS, "map.html")
 	if err != nil {
 		fmt.Errorf("Could not resolve template: %w", err)
 		panic(err)