Fun with JavaScript

We were going to go to the Fenland Country Show at Quy today but it was bucketing down with rain this morning so we looked set to stay home so I decided to have another play with my mapping site.

And I've had a fun day upgrading the track side of things. "Tracks" are records of where you've been - pulled off the GPS in GPX format you can upload them to my web site and see where you've been on an OS map. You've been able to do that for a while but today I enhanced this somewhat.

First I gave users the option to have markers displayed every few points (it defaults to every thirty but they can tweak this up or down). Click on a marker and a popup "speech bubble" tells you the date and time you were at that point and how high the GPS thinks you were¹.

Then I extended it to let you pick which tracks you displayed from the GPX file. This is necessary as people often forget to clear their track log so the GPX file has a record of a number of walks done on different days.

But the final bit was the addition on a "walker". When you click on the link to show the walker a yellow marker appears and "walks" along the track while the date, time and height are displayed at the side. You can pause him, or make him go faster or slower. It's a blast.

Try it with this track from our walk up the Corbett on Mull.

Things still to do include:

1. A way of overriding the track selection for our purposes. When users click on links like this one from our walk yesterday I don't want them to be bothered with the first screen.
2. Creating a height profile graph from the track - nothing to do with OS mapping per se but it's something people want.
3. Doing the same for a "route" - whether that's possible with the MultiMap Open API I've yet to discover.

But that's enough for today, I've got a roast to look forward to.

1. This is often quite badly wrong, especially if it's just got a fix, I saw -200m recorded in one GPX file I was using!