Inserting JSON in DataTable in Google Visualisation - gwt

Question

I read that JSON can be inserted into a datatable. However, its done
in JS on the HTML page (if memory serves right). I am using the GWT-
visualisation driver as given here, and the only methods to add a row are not
designed with JSON in mind. Is there any work-able solution? I am
trying to make a Stacked Column Chart.
Thanks.

Answer 1

I also struggled with this using geomap and data table combined. In my workaround I used the evalJSON() in prototype javascript framework to make the json string an object.
var country_obj = country_data.evalJSON(true);
Then I loop over the object's length :
var data = new google.visualization.DataTable();
data.addRows(country_obj.country.length);
data.addColumn('string', 'Country');
data.addColumn('number', map_context);
var j = country_obj.country.length;
for ( i = 0; i < j; i++ )
{
var num = new Number(country_obj.country[i].geo_mstat_reads);
data.setValue(i, 0, country_obj.country[i].country_name);
data.setValue(i, 1, num.valueOf());
}
// and then the table.draw() with the data
This worked very well for me because it scales to the exact size of the dataset you are trying to show.
Also you can do a whole whack of operations on an object which makes your life and coding easier to read and write.
I hope this helps you with your problem.

Answer 2

same pb, and don't know if it's feasible :
public native DataTable createDataTable(String obj) /*-{
console.log("create Datatable :" + obj);
var dt = new $wnd.google.visualization.DataTable(obj);
console.log("Datatable created");
return dt;
}-*/;
This create an empty dataTable whereas the JSON input is well formatted...