Leaflet Plugin: Leaflet.Elevation (height profile)

(@sinhex)

Hello,

i want to hack into the Trackservers Leaflet Libraries the Leaflet.Elevation Plugin:
https://github.com/MrMufflon/Leaflet.Elevation
you can see working static html test here, this is how it looks: https://dev.peterscheerer.de/playground/leaflet/02/example_gpx.html

The main problem i have: i don’t know how to hook in the current Track(s) from the Trackservers Database so the leaflet.elevation code can read it.

The Plugin itself is working, i loaded into trackserver.php:

				wp_enqueue_script( 'leaflet-gpx', TRACKSERVER_JSLIB . 'leaflet-gpx/gpx.js', array(), false, true );
				wp_enqueue_script( 'leaflet-elevation', TRACKSERVER_JSLIB . 'leaflet-elevation-0.0.4/leaflet.elevation-0.0.4.min.js', array(), false, true );
				wp_enqueue_style( 'leaflet-elevation', TRACKSERVER_JSLIB . 'leaflet-elevation-0.0.4/leaflet.elevation-0.0.4.css' );
				wp_enqueue_script( 'd3', TRACKSERVER_JSLIB . 'd3/d3.v3.min.js', array(), false, true );

and i put this code into trackserver.js

                var el = L.control.elevation({
                        theme: "steelblue-theme",
                        width: 400,
                        collapsed: true,
                 });
                 
                 el.addTo(map);  
                 
                 
        		var g=new L.GPX("./test.gpx", {async: true});
   
                      		
                 g.on("addline",function(e){
	                   el.addData(e.line);
                 });

what i want to do is now to change the hardcoded “./test.gpx” url into the current Track from Trackserver.

Any Ideas? Thanks pete

The page I need help with: [log in to see the link]

Viewing 3 replies - 1 through 3 (of 3 total)

kabouton
(@kabouton)

6 years, 5 months ago

Sinhex
Thats the same plugin I use. Please keep us posted how you do it. Thanks

Plugin Author tinuzz
(@tinuzz)

6 years, 5 months ago

Hi,

When Trackserver gets tracks from the database, it only uses the coordinates, not the timestamps or the elevation, because there wasn’t really any useful way to present them. The tracks are served in a format called ‘polyline’, that doesn’t have room for other data than coordinates.

If you want to create an altitude graph, a different format is needed. At one point, Trackserver supported GeoJSON, but that was never really used, and at current, it doesn’t work.

See https://github.com/tinuzz/wp-plugin-trackserver/blob/master/trackserver.php#L96

At the very least, you’d have to expand the function ‘send_as_geojson’ (https://github.com/tinuzz/wp-plugin-trackserver/blob/master/trackserver.php#L3310) to include elevation data and maybe also the timestamps.

But that function isn;t called anywhere in the code, because at some point the whole interaction between te client en the server has been redesigned and GeoJSON fell off the map, so to speak.

You would have to change the function ‘send_alltracks’ (https://github.com/tinuzz/wp-plugin-trackserver/blob/master/trackserver.php#L3343) to send GeoJSON instead of Polyline, and then there may be some work needed on the JavaScript side as well.

So, in short: this is going to be quite some work. I’m afraid it’s not something I can dedicate a lot of time to, but I’m open to pull requests on Github.

Please let me know if you have any more questions!

Cheers,
Martijn.

Plugin Author tinuzz
(@tinuzz)

6 years, 5 months ago

Hm, I forgot about something. See that as the Elevation plugin also supports GPX files, your best bet may be the GPX support in Trackserver.

Trackserver can send GPX files with multiple tracks inside, except this functionality is only implemented in the [tslink] shortcode and is currently not suitable for consumption in other ways. But that could be a lot easier to implement than GeoJSON support.

https://github.com/tinuzz/wp-plugin-trackserver/blob/master/trackserver.php#L1772

I think I can do something in that respect. I am preparing a new Trackserver release, it should be here before the end of the year with a lot of new features. I will have a look and see if I can improve the support for different formats a little.

Cheers,
Martijn.

Viewing 3 replies - 1 through 3 (of 3 total)

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