Capture lat/long from html5 and update node via rules component?

Hi,

I am creating a system where staff go and visit clients.. We have a view with appointments and when the staff arrive the select the appointment and click a VBO link that runs a rules component to update a time field.. At the same time I would like to capture and store the html5 location data to a lat/long geofield.. I see there is some support for geofield in rules but I couldn't see a way for it to use the location data from the logged in user's browser..

Any ideas?

Thanks..