Use TopoJSON for smaller files

gulpfile.js

@@ -79,7 +79,7 @@ var paths = {
         'layers/config/geometry.js',
     ],
     layersConfigDestName: 'layersConf.js',
-    boundaries: 'resources/boundaries/*.geojson',
+    boundaries: ['resources/boundaries/*.geojson', 'resources/boundaries/*.topo.json'],
     zip: ['dist/**', 'index.html', 'config.template.js', 'keys.template.js'],
     dest: 'dist',
     destName: 'brouter-web',

js/Util.js

@@ -30,6 +30,38 @@ BR.Util = {
         return new Error(msg);
     },
 
+    getJson: function (url, context, cb) {
+        BR.Util.get(url, function (err, data) {
+            if (err) {
+                BR.message.showError('Error getting ' + context + ': ' + err);
+                return cb(err);
+            }
+
+            try {
+                var json = JSON.parse(data);
+                cb(null, json);
+            } catch (err) {
+                BR.message.showError('Error parsing ' + context + ': ' + err);
+                console.error(err);
+                cb(err);
+            }
+        });
+    },
+
+    getGeoJson: function (url, context, cb) {
+        BR.Util.getJson(url, context, function (err, data) {
+            if (err) return cb(err);
+
+            var geoJson = data;
+            if (data && data.type && data.type === 'Topology') {
+                var key = Object.keys(data.objects)[0];
+                geoJson = topojson.feature(data, data.objects[key]);
+            }
+
+            cb(null, geoJson);
+        });
+    },
+
     // check if localStorage is available, especially for catching SecurityError
     // when cookie settings are blocking access (Chrome, Pale Moon, older Firefox)
     //

js/plugin/CircleGoArea.js

@@ -7,7 +7,7 @@ BR.CircleGoArea = L.Control.extend({
     options: {
         radius: 1000, // in meters
         stateRules: false,
-        statesUrl: BR.conf.statesUrl || 'dist/boundaries/germany-states.geojson',
+        statesUrl: BR.conf.statesUrl || 'dist/boundaries/germany-states.topo.json',
         overpassBaseUrl: BR.conf.overpassBaseUrl || 'https://overpass-api.de/api/interpreter?data=',
         shortcut: {
             draw: {
@@ -276,28 +276,21 @@ BR.CircleGoArea = L.Control.extend({
     },
 
     _loadStates: function (cb) {
-        BR.Util.get(
+        BR.Util.getGeoJson(
             this.options.statesUrl,
+            'states',
             L.bind(function (err, data) {
-                if (err) {
-                    BR.message.showError('Error getting states: ' + err);
-                    return;
-                }
+                // TODO spinner aus?, mit ringgo parameter testen
+                if (err) return;
 
-                try {
-                    this.states = JSON.parse(data);
+                this.states = data;
 
                 // debugging
                 //this._logStates(this.states);
                 //this._addStatesLayer(this.states);
 
                 this.fire('states:loaded');
-
                 cb();
-                } catch (err) {
-                    BR.message.showError('Error parsing states: ' + err);
-                    console.error(err);
-                }
             }, this)
         );
     },

package.json

@@ -74,6 +74,7 @@
         "mapbbcode": "MapBBCode/mapbbcode#v1.2.0",
         "osmtogeojson": "^3.0.0-beta.4",
         "promise-polyfill": "^8.2.0",
+        "topojson-client": "^3.1.0",
         "url-search-params": "~0.5.0",
         "whatwg-fetch": "^3.5.0"
     },

resources/boundaries/README.md

@@ -1,11 +1,25 @@
 # boundaries
 
-## germany-states.geojson
+Downloaded from https://osm-boundaries.com.
+
+TopoJSON (https://github.com/topojson/topojson) used to convert to topology, simplify and reduce precision:
+`npm install -g topojson`
+
+## germany-states
 
 Currently only containing states that do not use the municipality boundary for the Corona 15 km allowed zone rule.
 
-Downloaded from https://osm-boundaries.com with:
 
 ```
-curl --remote-name --remote-header-name --location --max-redirs -1 "https://osm-boundaries.com/Download/Submit?apiKey=YOUR_API_KEY&db=osm20201109&osmIds=-28322,-62771,-62372,-62467,-62607,-62422,-62782,-62504&includeAllTags&simplify=0.0001"
+curl --remote-name --remote-header-name --location --max-redirs -1 "https://osm-boundaries.com/Download/Submit?apiKey=YOUR_API_KEY&db=osm20201109&osmIds=-28322,-62771,-62372,-62467,-62607,-62422,-62782,-62504&includeAllTags"
+
+geo2topo germany-states.geojson | toposimplify -s 3e-12 | topoquantize 1e6 > germany-states.topo.json
+```
+
+## countries
+
+```
+curl --remote-name --remote-header-name --location --max-redirs -1 "https://osm-boundaries.com/Download/Submit?apiKey=YOUR_API_KEY&db=osm20201109&osmIds=-51477,-1403916"
+
+geo2topo countries.geojson | toposimplify -s 3e-12 | topoquantize 1e6 > countries.topo.json
 ```

yarn.lock

@@ -8173,7 +8173,7 @@ toidentifier@1.0.0:
   resolved "https://registry.yarnpkg.com/toidentifier/-/toidentifier-1.0.0.tgz#7e1be3470f1e77948bc43d94a3c8f4d7752ba553"
   integrity sha512-yaOH/Pk/VEhBWWTlhI+qXxDFXlejDGcQipMlyxda9nthulaxLZUNcUqFxokp0vcYnvteJln5FNQDRrxj3YcbVw==
 
-topojson-client@3:
+topojson-client@3, topojson-client@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/topojson-client/-/topojson-client-3.1.0.tgz#22e8b1ed08a2b922feeb4af6f53b6ef09a467b99"
   integrity sha512-605uxS6bcYxGXw9qi62XyrV6Q3xwbndjachmNxu8HWTtVPxZfEJN9fd/SZS1Q54Sn2y0TMyMxFj/cJINqGHrKw==