export value of checkboxes to excel in jQuery datatables

SOLUTION

You're using DataTables 1.10.8. Before this version (1.10.7 and earlier) there was TableTools with fnCellRender option that would help to do what you want. Since 1.10.8 TableTools extension has been replaced with Buttons extension.

With Buttons extension you may use exportOptions and tell DataTables that you want the the data used for sorting (orthogonal: 'sort'). Then you need to define render function and return appropriate data when sorting is performed (type === 'sort').

/*
 * Create an array with the values of all the checkboxes in a column 
 */
$.fn.dataTable.ext.order['dom-checkbox'] = function (settings, col) {
    return this.api()
        .column(col, { order: 'index' })
        .nodes()
        .map(function (td, i) {
            return $('input', td).prop('checked') ? '1' : '0';
        });
};

var table = $('#example1').DataTable({
    dom : 'Bfrtlip',    
    buttons: [
        {
            extend: 'excel',
            exportOptions: {
                orthogonal: 'sort'
            }
        }        
    ],
    columnDefs: [{
       targets:[0,5],
       orderDataType: 'dom-checkbox',
       render: function(data, type, row, meta){
          if(type === 'sort'){
             var api = new $.fn.dataTable.Api( meta.settings );
             var $input = $(api.cell({ row: meta.row, column: meta.col }).node()).find('input');
             data = $input.prop('checked') ? '1' : '0';
          }
           
          return data;    
       }
    }]
});

table.buttons().container()
    .appendTo( $('.col-sm-6:eq(0)', table.table().container() ) );

DEMO

See this jsFiddle for code and demonstration.