When accessing the Google maps list through https://www.google.com/maps and the "Saved" menu entry to the left, a request to www.google.com/maps/preview/entitylist/getlist returns a json-like data structure that contains the name, comment and coordinates of the entries in the list.
The first 4 characters of the returned value are not part of the json data structure. In the remaining object, the list of places is found in a nested list in cleaned_data[[1]][[9]] (R notation).
The elements of this list can be parsed with a an R function like this:
# Function to convert a single entry to a GPX waypoint
to_gpx <- function(x) {
# Extract name, latitude, longitude, and comment from the list
name <- x[[3]]
lat <- x[[2]][[6]][3]
lon <- x[[2]][[6]][4]
comment <- x[[4]] # Extract the comment
# Create the GPX waypoint string including the comment as description
gpx_string <- paste0(
'<wpt lat="', lat, '" lon="', lon, '">',
'<name>', name, '</name>',
'<desc>', comment, '</desc>',
'</wpt>'
)
return(gpx_string)
}
To not having to deal with credentials and sessions and stuff, I made a firefox plugin that parses any replies from that url and converts them to gpx. The source code can be found here: https://github.com/tux2000/Google-Maps-Lists-GPX-Exporter-Firefox and the plugin can be installed from here: https://addons.mozilla.org/en-US/firefox/addon/google-maps-lists-gpx-exporter/