Format basic GPX

js/format/Gpx.js

@@ -0,0 +1,76 @@
+BR.Gpx = {
+    format: function (geoJson) {
+        const gpx = togpx(geoJson, {
+            featureDescription: function () {},
+        });
+        const statsComment = BR.Gpx._statsComment(geoJson);
+        const xml = '<?xml version="1.0" encoding="UTF-8"?>' + statsComment + gpx;
+        return BR.Gpx.pretty(xml, 1);
+    },
+
+    // <!-- track-length = 319 filtered ascend = 2 plain-ascend = -1 cost=533 energy=.0kwh time=44s -->
+    _statsComment: function (geoJson) {
+        const props = geoJson.features?.[0].properties;
+        if (!props) return '';
+
+        let comment = '<!--';
+        comment += ' track-length = ' + props['track-length'];
+        comment += ' filtered ascend = ' + props['filtered ascend'];
+        comment += ' plain-ascend = ' + props['plain-ascend'];
+        comment += ' cost=' + props['cost'];
+        if (props['total-energy']) {
+            // TODO 'wh'? (also for stats, see issue),
+            // see brouter OsmTrack.getFormattedEnergy
+            comment += ' energy=' + (props['total-energy'] / 3600000).toFixed(1) + 'kwh';
+        }
+        if (props['total-time']) {
+            // TODO format, e.g. total-time=14833 -> time=4h 7m 13s
+            // see brouter OsmTrack.getFormattedTime2
+            comment += ' time=' + props['total-time'] + 's';
+        }
+        comment += ' -->';
+        return comment;
+    },
+
+    // modified version of
+    // https://gist.github.com/sente/1083506#gistcomment-2254622
+    // MIT License, Copyright (c) 2016 Stuart Powers, ES6 version by Jonathan Gruber
+    pretty: function (xml, indentSize = 2) {
+        const PADDING = ' '.repeat(indentSize);
+        const newline = '\n';
+        // break into lines, keep trkpt with subelement ele in single line
+        const reg = /(>)(<)(?!ele|\/trkpt)(\/?)/g;
+        let pad = 0;
+
+        xml = xml.replace('<metadata/>', '');
+        xml = xml.replace(reg, `$1${newline}$2$3`);
+
+        let lines = xml.split(newline);
+        lines = lines.map((node, index) => {
+            let indent = 0;
+            if (node.match(/.+<\/\w[^>]*>$/)) {
+                indent = 0;
+            } else if (node.match(/^<\/\w/) && pad > 0) {
+                pad -= 1;
+            } else if (node.match(/^<\w[^>]*[^\/]>.*$/)) {
+                indent = 1;
+            } else {
+                indent = 0;
+            }
+
+            pad += indent;
+
+            return PADDING.repeat(pad - indent) + node;
+        });
+
+        for (const [i, line] of lines.entries()) {
+            // break gpx attributes into separate lines
+            if (line.includes('<gpx ')) {
+                lines[i] = line.replace(/ ([a-z:]+=")/gi, ` ${newline}${PADDING}$1`);
+                break;
+            }
+        }
+
+        return lines.join(newline);
+    },
+};