GPX plugin for Leaflet


Leaflet is a Javascript library for displaying
interactive maps. This plugin, based on the work of Pavel
Shramov and his
leaflet-plugins, allows for
displaying and analyzing GPX tracks and their waypoints so they can be
displayed on a Leaflet map as a new layer.

As it parses the GPX data, leaflet-gpx records information about the
GPX track, including total time, moving time, total distance, elevation
stats and heart-rate, and makes it accessible through an exhaustive set
of accessor methods.

GPX parsing will automatically handle pauses in the track with a default
tolerance interval of 15 seconds between points. You can configure this
interval by setting max_point_interval, in milliseconds, in the options
passed to the GPX constructor.

I've put together a complete example as a
demo.

License

leaflet-gpx is under the BSD 2-clause license. Please refer to the
attached LICENSE file and/or to the copyright header in gpx.js for more
information.

Usage

Usage is very simple:

* Include the Leaflet stylesheet and script, and the leaflet-gpx script,
in your HTML page;
* Create your Leaflet map, with your choice of base layer(s);
* Create the L.GPX layer to display your GPX track.

``html















`

$3

`javascript
const map = L.map('map');
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
attribution: 'Map data © OpenStreetMap'
}).addTo(map);

await import('gpx.js').then((module) => {
new L.GPX('https://...').on('loaded', (e) => {
map.fitBounds(e.target.getBounds());
}).addTo(map);
});
`

Functions

If you want to display additional information about the GPX track, you can do
so in the 'loaded' event handler, calling one of the following methods on the
GPX object e.target:

* get_name(): returns the name of the GPX track
* get_distance(): returns the total track distance, in meters
* get_start_time(): returns a Javascript Date object representing the
starting time
* get_end_time(): returns a Javascript Date object representing when the
last point was recorded
* get_moving_time(): returns the moving time, in milliseconds
* get_total_time(): returns the total track time, in milliseconds
* get_moving_pace(): returns the average moving pace in milliseconds per km
* get_moving_speed(): returns the average moving speed in km per hour
* get_total_speed(): returns the average total speed in km per hour
* get_elevation_min(): returns the lowest elevation, in meters
* get_elevation_max(): returns the highest elevation, in meters
* get_elevation_gain(): returns the cumulative elevation gain, in meters
* get_elevation_loss(): returns the cumulative elevation loss, in meters
* get_speed_max(): returns the maximum speed in km per hour
* get_average_hr(): returns the average heart rate (if available)
* get_average_cadence(): returns the average cadence (if available)
* get_average_temp(): returns the average of the temperature (if available)

If you're not a fan of the metric system, you also have the following methods
at your disposal:

* get_distance_imp(): returns the total track distance in miles
* get_moving_pace_imp(): returns the average moving pace in milliseconds per
mile
* get_moving_speed_imp(): returns the average moving speed in miles per hour
* get_total_speed_imp(): returns the average total speed in miles per hour
* get_elevation_min_imp(): returns the lowest elevation, in feet
* get_elevation_max_imp(): returns the highest elevation, in feet
* get_elevation_gain_imp(): returns the cumulative elevation gain, in feet
* get_elevation_loss_imp(): returns the cumulative elevation loss, in feet
* get_speed_max_imp(): returns the maximum speed in miles per hour

The reason why these methods return milliseconds is that you have at your
disposal nice helper methods to format a duration in milliseconds into a cool
string:

* get_duration_string(duration, hidems) format to a string like 3:07'48"
or 59'32.431, where duration is in
milliseconds and hidems is an optional boolean you can use to request never
to display millisecond precision.
* get_duration_string_iso(duration, hidems) formats to an ISO like
representation like 3:07:48 or 59:32.431, where duration is in
milliseconds and hidems is an optional boolean you can use to request never
to display millisecond precision.

You can also get full elevation, heartrate, cadence and temperature data with:

* get_elevation_data() and get_elevation_data_imp()
* get_speed_data() and get_speed_data_imp()
* get_heartrate_data() and get_heartrate_data_imp()
* get_cadence_data() and get_cadence_data_imp()
* get_temp_data() and get_temp_data_imp()

These methods all return an array of points [distance, value, tooltip] where
the distance is either in kilometers or in miles and the elevation in meters or
feet, depending on whether you use the _imp variant or not. Heart rate,
obviously, doesn't change.

Reloading

You can make leaflet-gpx reload the source GPX file by calling the
reload() method. For example, to trigger a reload every 5 seconds, you
can do:

`javascript
var gpx = new L.GPX(url);
setInterval(function() {
gpx.reload();
}, 5000);
`

About marker icons

$3

By default, leaflet-gpx uses Leaflet's default icon image for all
markers. You can override this behavior by providing a Leaflet Icon
object, or the path or URL to an image to use as the marker, for any of
the markers supported by this plugin as part of the markers parameter:

`javascript
new L.GPX(url, {
async: true,
markers: {
startIcon: ...,
endIcon: ...
wptIcons: { ... },
wptTypeIcons: { ... },
pointMatchers: [ ... ],
}
}).on('loaded', function(e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
`

* startIcon is used for the marker at the beginning of the GPX track;
* endIcon is used for the marker at the end of the GPX track;
* wptIcons and wptTypeIcons are mappings of waypoint symbols and
types to the icon you want to use for each;
* pointMatchers is an array of custom point matchers and their
respective icon (see below);

You can also override any of those to null to disable the
corresponding marker altogether.

Here is how you would override the URL of the provided icons for start
and end markers, but none of the other types of markers:

`javascript
new L.GPX(url, {
async: true,
markers: {
startIcon: 'images/pin-icon-start.png',
endIcon: 'images/pin-icon-end.png',
}
}).on('loaded', function(e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
`

It's usually preferrable and more flexible to provide a Leaflet Icon
instance directly, for example from
leaflet-awesome-markers. See
for more information.

`javascript
new L.GPX(url, {
async: true,
markers: {
wptIcons: {
'Coffee shop': new L.AwesomeMarkers.icon({
icon: 'coffee',
prefix: 'fa',
markerColor: 'blue',
iconColor: 'white'
})
}
}
}).on('loaded', function (e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
`

$3

You can fine tune marker options using any of the parameters expected by
Leaflet's base L.Icon class
using the marker_options parameters:

`javascript
new L.GPX(url, {
async: true,
marker_options: {
iconSize: [38, 95],
iconAnchor: [22, 94],
}
}).on('loaded', function(e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
`

$3

Note that you do not need to override all the marker definitions, or
marker options, when providing the markers and marker_options
parameters to the GPX constructor as this plugin will use sensible
defaults for all of those settings.

About waypoints

By default, this plugin will parse all Waypoints from a GPX file. This
can be controlled via the value waypoint in gpx_options, e.g.
parseElements: ['track', 'route', 'waypoint'].

The icon used in the marker representing each track waypoint is
determined based on the waypoint's properties, in this order:

* If the waypoint has a sym attribute, the markers.wptIcons[sym]
icon is used;
* If the waypoint has a type attribute, the markers.wptTypeIcons[type]
icon is used;
* Point matchers are evaluated in order, if one matches the waypoint's
name attribute, its icon is used (see _Named markers_ below);
* If none of the above rules match, the default '' (empty string) icon
entry in wptIcons is used.

`javascript
new L.GPX(url, {
async: true,
markers: {
wptIcons: {
'': new L.Icon.Default,
'Geocache Found': 'img/gpx/geocache.png',
'Park': 'img/gpx/tree.png'
},
}
}).on('loaded', function (e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
`

Named points

GPX points can be named, for example to denote certain POIs (points of
interest). You can setup rules to match point names to create labeled
markers for those points by providing a pointMatchers array in the
markers constructor parameter.

Each element in this array must define a regex to match the point's
name and an icon definition (a L.Icon or subclass object, or the URL
to an icon image).

Each named point in the GPX track is evaluated against those rules and
a marker is created with the point's name as label from the first
matching rule. This also applies to named waypoints, but keep in mind
that waypoint icons rules take precedence over point matchers.

`javascript
new L.GPX(url, {
async: true,
markers: {
pointMatchers: [
{
regex: /Coffee/,
icon: new L.AwesomeMarkers.icon({
icon: 'coffee',
markerColor: 'blue',
iconColor: 'white'
}),
},
{
regex: /Home/,
icon: new L.AwesomeMarkers.icon({
icon: 'home',
markerColor: 'green',
iconColor: 'white'
}),
}
]
}
}).on('loaded', function(e) {
map.fitToBounds(e.target.getBounds());
}).addTo(map);
`

Events

Events are fired on the L.GPX object as the GPX data is being parsed
and the map layers generated. You can listen for those events by
attaching the corresponding event listener on the L.GPX object:

`javascript
new L.GPX(url, async: true, {
// options
}).on('addpoint', function(e) {
console.log('Added ' + e.point_type + ' point: ' + e.point);
}).on('loaded', function(e) {
var gpx = e.target;
map.fitToBounds(gpx.getBounds());
}).on('error', function(e) {
console.log('Error loading file: ' + e.err);
}).addTo(map);
`

Note that for your event listeners to be correctly triggered, you need
to pass async: true to the L.GPX constructor; otherwise the parsing
of the GPX happens synchronously in the constructor before you your
event listeners get registered!

addpoint events are fired for every marker added to the map, in
particular for the start and end points, all the waypoints, and all the
named points that matched pointMatchers rules. Each addpoint event
contains the following properties:

- point: the marker object itself, from which you can get or modify
the latitude and longitude of the point and any other attribute of the
marker.
- point_type: one of start, end, waypoint or label, allowing
you to identify what type of point the marker is for.
- element: the track point element the marker was created for.

One use case for those events is for example to attach additional
content or behavior to the markers that were generated (popups, etc).

error events are fired when no layers of the type(s) specified in
options.gpx_options.parseElements can be parsed out of the given
file. For instance, error would be fired if a file with no waypoints
was attempted to be loaded with parseElements set to ['waypoint'].
Each error event contains the following property:

- err: a message with details about the error that occurred.

Line styling

leaflet-gpx understands the GPX
Style extension, and will
extract styling information defined on routes and track segments to use
for drawing the corresponding polyline.

`xml



FF0000
0.5
1
square
square
0,10
3




`

You can override the style of the lines by passing a polyline_options
array into the options argument of the L.GPX constructor, each
element of the array defines the style for the corresponding route
and/or track in the file (in the same order).

`javascript
new L.GPX(url, {
polyline_options: [{
color: 'green',
opacity: 0.75,
weight: 3,
lineCap: 'round'
},{
color: 'blue',
opacity: 0.75,
weight: 1
}]
}).on('loaded', function(e) {
var gpx = e.target;
map.fitToBounds(gpx.getBounds());
}).addTo(map);
`

If you have many routes or tracks in your GPX file and you want them to
share the same styling, you can pass polyline_options as a single
object rather than an array (this is also how leaflet-gpx worked
before the introduction of the array):

`javascript
new L.GPX(url, {
polyline_options: {
color: 'green',
opacity: 0.75,
weight: 3,
lineCap: 'round'
}
}).on('loaded', function(e) {
var gpx = e.target;
map.fitToBounds(gpx.getBounds());
}).addTo(map);
`

For more information on the available polyline styling options, refer to
the Leaflet documentation on
Polyline. By
default, if no styling is available, the line will be drawn in _blue_.

GPX parsing options

$3

Some GPX tracks contain the actual route/track twice, both the
and elements are used. You can tell leaflet-gpx which tag to
use or to use both (which is the default setting for backwards
compatibility). The parseElements field of gpx_options controls this
behavior. It should be an array that contains 'route' and/or 'track'
and/or 'waypoint'.

$3

GPX file may contain multiple tracks represented by elements,
each track possibly composed of multiple segments with
elements. Although this plugin will always represent each GPX route and
each GPX track as distinct entities with their own start and end
markers, track segments will by default be joined into a single line.

You can disable this behavior by setting the joinTrackSegments flag to
false in the gpx_options:

`javascript
new L.GPX(url, {
gpx_options: {
joinTrackSegments: false
}
}).on('loaded', function(e) {
map.fitBounds(e.target.getBounds());
}).addTo(map);
``

Caveats

* Distance calculation is relatively accurate, but elevation change
calculation is not topographically adjusted, so the total elevation
gain/loss/change might appear inaccurate in some situations.
* Currently doesn't seem to work in IE8/9. See #9 and #11 for
discussion.