Strava API - How to get route image

Question

Does anyone know how to get finish route map image after users post their activity on Strava. I have read Strava API document, but I haven't found it yet

I use https://strava.github.io/api/v3/activities/:id to get an activity, there is "map" field, but I still not find out this field description.

Thanks everyone.

Answer 1

Strava takes the set of lat/longs recorded, and encodes them using the GOOGLE POLYLINE ENCODING algorithm. This is in order to reduce the data transmitted through the APP and the WEB SERVICE.

If you need to draw the route, you need to

1. Take the polyline string.
2. Decode it to get an array of lat/lon.
3. Loop through the array and draw the polyline on the maps.

I used the @mapbox/polyline npm module to decode the polyline in javascript.

Another, and a better way to do that is that you use the google maps static api. Where you will input a polyline, and get an image with a route drawn. The static api will look like

https://maps.googleapis.com/maps/api/staticmap?size=600x300&maptype=roadmap&path=enc:GIVE_YOUR_POLYLINE_DATA&key=GIVE_YOUR_API_KEY

Answer 2

The summary_polyline can be decoded into a set of coordinates. The algorithm used for a polyline is described here and lots of libraries can handle it.

You can also use the Google Maps static API for example without decoding.

This Ruby code from a slack bot for Strava does it all.