GeoGPXer is a JavaScript library designed to convert GPX data into GeoJSON format efficiently. It supports the conversion of waypoints, tracks, and routes, with additional handling for GPX extensions.
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此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.cn-greasyfork.org/scripts/523870/1521198/GeoGPXer.js
/**
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Derived from logic of https://github.com/M-Reimer/gpx2geojson/tree/master
*/
/**
* @desc The GeoGPXer namespace.
* @namespace
* @global
*/
var GeoGPXer = (function() {
// Define the GeoGPXer constructor
function GeoGPXer(obj) {
if (obj instanceof GeoGPXer) return obj;
if (!(this instanceof GeoGPXer)) return new GeoGPXer(obj);
this._wrapped = obj;
}
/**
* @desc Parses GPX text and returns an XML Document.
* @param {String} gpxText - The GPX data as a string.
* @return {Document} Parsed XML Document.
*/
GeoGPXer.prototype.read = function(gpxText) {
return new DOMParser().parseFromString(gpxText, "application/xml");
};
/**
* @desc Converts an XML Document to GeoJSON FeatureCollection.
* @param {Document} document - Parsed XML document of GPX data.
* @return {Object} GeoJSON FeatureCollection.
*/
GeoGPXer.prototype.toGeoJSON = function(document) {
const features = [];
for (const n of document.firstChild.childNodes) {
switch (n.tagName) {
case "wpt":
features.push(this.wptToPoint(n));
break;
case "trk":
features.push(this.trkToMultiLineString(n));
break;
case "rte":
features.push(this.rteToLineString(n));
break;
}
}
return {
type: "FeatureCollection",
features: features
};
};
/**
* @desc Extracts coordinates from a node.
* @param {Node} node - GPX node containing coordinates.
* @return {Array} Array of coordinates [longitude, latitude].
*/
GeoGPXer.prototype.coordFromNode = function(node) {
return [
parseFloat(node.getAttribute("lon")),
parseFloat(node.getAttribute("lat"))
];
};
/**
* @desc Creates a GeoJSON feature.
* @param {String} type - Type of geometry (Point, LineString, etc.).
* @param {Array} coords - Coordinates for the geometry.
* @param {Object} props - Properties of the feature.
* @return {Object} GeoJSON feature.
*/
GeoGPXer.prototype.makeFeature = function(type, coords, props) {
return {
type: "Feature",
geometry: {
type: type,
coordinates: coords
},
properties: props
};
};
/**
* @desc Converts a waypoint node to a GeoJSON Point feature.
* @param {Node} node - GPX waypoint node.
* @return {Object} GeoJSON Point feature.
*/
GeoGPXer.prototype.wptToPoint = function(node) {
const coord = this.coordFromNode(node);
const props = this.extractProperties(node);
return this.makeFeature("Point", coord, props);
};
/**
* @desc Converts a track node to a GeoJSON MultiLineString feature.
* @param {Node} node - GPX track node.
* @return {Object} GeoJSON MultiLineString feature.
*/
GeoGPXer.prototype.trkToMultiLineString = function(node) {
const coordslst = [];
const props = this.extractProperties(node);
for (const n of node.childNodes) {
if (n.tagName === "trkseg") {
const coords = [];
coordslst.push(coords);
for (const trkpt of n.getElementsByTagName("trkpt")) {
coords.push(this.coordFromNode(trkpt));
}
}
}
return this.makeFeature("MultiLineString", coordslst, props);
};
/**
* @desc Converts a route node to a GeoJSON LineString feature.
* @param {Node} node - GPX route node.
* @return {Object} GeoJSON LineString feature.
*/
GeoGPXer.prototype.rteToLineString = function(node) {
const coords = [];
const props = this.extractProperties(node);
for (const n of node.childNodes) {
if (n.tagName === "rtept") {
coords.push(this.coordFromNode(n));
}
}
return this.makeFeature("LineString", coords, props);
};
/**
* @desc Extracts properties from a GPX node.
* @param {Node} node - GPX node.
* @return {Object} Properties extracted from the node.
*/
GeoGPXer.prototype.extractProperties = function(node) {
const props = {};
for (const n of node.childNodes) {
if (n.nodeType === Node.ELEMENT_NODE && n.tagName !== "extensions") {
props[n.tagName] = n.textContent;
}
}
const extensions = node.getElementsByTagName("extensions");
if (extensions.length > 0) {
for (const ext of extensions[0].childNodes) {
if (ext.nodeType === Node.ELEMENT_NODE) {
props[`ex_${ext.tagName}`] = ext.textContent;
}
}
}
return props;
};
return GeoGPXer; // Return the GeoGPXer constructor
})();