Pull data from excel using SheetJS library

Question

The following program uses a static JSON object as its data source. I just want to replace the JSON Object with an excel file. It seems to be possible using SheetJS library but I cannot find a working sample that uses a file link instead of a File upload mechanism. How to replace the JSON object with an excel file as the data source in the following code and pull data using SheetJS library?

 google.load('visualization', '1', {'packages':['table']});
    var SiteData = SiteInfo();
    var map;
    function initialize() 
    {  
  map = new google.maps.Map(document.getElementById('map_canvas'), {
    center: new google.maps.LatLng(55.7200,12.5700),
    zoom: 2,
    mapTypeControl: false,
    streetViewControl: false,
    mapTypeId: google.maps.MapTypeId.ROADMAP
      });
  for(m=0;m<SiteData.length;m++)
  {
    var image;
    if(SiteData[m].Connection=="Sitetype1")
    {
      image = "http://labs.google.com/ridefinder/images/mm_20_white.png";  
    }
    else if(SiteData[m].Connection=="sitetype2")
    {
      image = "http://labs.google.com/ridefinder/images/mm_20_black.png";
    }
    else
    {
        image = "http://labs.google.com/ridefinder/images/mm_20_purple.png";
    }
    setmarkers(map,SiteData[m].Latitude,SiteData[m].Longitude,image)
  }
}
function setmarkers(map,lat,lon,image)
{
    var latlon = new google.maps.LatLng(lat,lon);
    var marker = new google.maps.Marker({map:map,position:latlon,icon:image});
}
function Changesite(sc)
{   
    var mpls = Outage();
    for(var i=0,numSite = SiteData.length;i<numSite;i++)
    {
        if(SiteData[i].Sitecode==sc)
        {
            var data = new google.visualization.DataTable();
            data.addColumn('String', 'sitecode');
            data.addColumn('String', SiteData[i].Sitecode);
            data.addRows([
              ['Connection', SiteData[i].Connection],
              ['Bandwidth', SiteData[i].Bandwidth],
              ['Address', SiteData[i].Address],
              ['Country', SiteData[i].Country],
                 ]);
            var chart = new google.visualization.Table

(document.getElementById('chart'));
            var options = {
                    'title': SiteData[i].Sitecode+ ' ',
                             };
            chart.draw(data, options);
      }
    }
    }
function SiteInfo()
{
    var Siteinfo = 

[{"Connection":"Direct","Sitecode":"site1","Address":"Usa","Bandwidth":"6 

Mbps","Country":"USA","Latency":"44 ms","Latitude":44,"Longitude":34,"Item 

Type":"Item"}];
return Siteinfo;
}
function Outage()
{
    var Outage_Data= [{"COUNTRY":"USA ","SITECODE":"site1","Outage 

":"Issue1","DATE ":"4/1/2015"}];
    return Outage_Data;
}