Is it possible to make a draggable marker and get its coordinates in gmaps4rails so that the user can drag the marker to select the point he needs and get the selected point coordinates?
It is not realized in a gem.
But do not forget that you have access to all created objects. For example, a card can be obtained using:Gmaps4Rails.map
Gmaps4Rails.map
You could inspire: https://github.com/apneadiving/Google-Maps-for-Rails/wiki/Javascript-goodies