Tracking of vehicles in Rails via geocoding and plotting on a map - ruby-on-rails-3

Question

I have a Rails 3.2.19 app that I'd like to track vehicles (Units) with using geocoding and plotting on Google Maps.
I came up with a way to get coordinates by using the taip_parser gem and creating a rake task that constantly listens for inbound taip data, parses the latitude and longitude and updates the vehicle model's latitude and longitude fields. From there I was able to plot vehicle locations using the gmaps4rails gem. The limitation of this is that you have to use a specific 3G/4G modem that speaks in TAIP to send the lat/long to the Rails server so the rake task can parse it.
What I'd like to do is to negate having to use these expensive 3G/4G modems and instead pull the coordinates from a mobile device located in the vehicle (currently an iPad).
So my thoughts are to use the HTML5 Geolocation feature in the browser to obtain the latitude and longitude of the unit and somehow store that into the Unit's latitude/longitude database fields upon page/partial refresh which happens currently via Ajax.
This would break the dependence on the the existing devices and allow any mobile GPS enabled device to be compatible with this feature.
Currently in my app I have gmaps4rails to plot the units using my rake task and taip data parsing and also geocoder which I'm testing to geocode addresses as they are created for another purpose.
My questions are:
Can someone provide an example of how to use the HTML5 geolocation feature in a rails view? Once HTML5 geolocation is enabled in the view, how to get the latitude and longitude into the respective models latitude and longitude fields? Perhaps an example iteration of multiple objects' latitude longitude using gmaps4rails
If my question is too vague or convoluted please let me know so I can edit it and make things more clear as to what I'm trying to do.

Answer 1

I was able to get this working by using some ajax and a custom controller action in my Rails app. Using Ajax and a hidden form, I pull the coordinates using HTML5, populate the form with the values, and to an ajax post submit.
See below for the code:
controller
def update_gps
#unit = current_user.unit
if #unit.update_attributes(params[:unit])
respond_to do |format|
format.html {redirect_to mdt_path}
format.js { render "index"}
end
end
end
index.html.erb
<div class="hidden">
<%= form_for(#unit, :url => update_gps_mdt_index_path, :html => {:method => :post}) do |f| %>
<%= f.text_field :latitude %>
<%= f.text_field :longitude %>
<%= f.button :submit %>
<% end %>
</div>
<script>
$(function() {
setInterval(function(){
$.getScript("/mdt");
}, 10000);
});
function updateCurrentLocation(){
navigator.geolocation.getCurrentPosition(function(position) {
var c = position.coords
var location = c.latitude +", "+ c.longitude
console.log(location)
var $updateLocationForm = $(".edit_unit")
$("#unit_latitude").val(c.latitude)
$("#unit_longitude").val( c.longitude)
var data = $(".edit_unit").serialize();
console.log(data)
$.ajax({
type: "POST",
url: $(".edit_unit").attr("action"),
data: data,
success: function(data) {
console.log('working: '+data);
},
error: function(msg) {
console.log('not working '+msg);
}
});
});
}
setInterval(updateCurrentLocation, 10000)
</script>