// An HTTP handler which returns a tileset's `layer.json` file
func LayerHandler(store stores.Storer) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
var (
err error
layer []byte
)
defer func() {
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
log.Err(err.Error())
}
}()
vars := mux.Vars(r)
// Try and get a `layer.json` from the stores
layer, err = store.Layer(vars["tileset"])
if err == stores.ErrNoItem {
err = nil // don't persist this error
if store.TilesetStatus(vars["tileset"]) == stores.NOT_FOUND {
http.Error(w,
fmt.Errorf("The tileset `%s` does not exist", vars["tileset"]).Error(),
http.StatusNotFound)
return
}
// the directory exists: send the default `layer.json`
layer = []byte(`{
"tilejson": "2.1.0",
"format": "heightmap-1.0",
"version": "1.0.0",
"scheme": "tms",
"tiles": ["{z}/{x}/{y}.terrain"]
}`)
} else if err != nil {
return
}
headers := w.Header()
headers.Set("Content-Type", "application/json")
w.Write(layer)
}
}
