class.js

function ReportChart(url) {
  this.url = url;
}

ReportChart.prototype.getChart = function() {
  $.get(
    this.url,
    function(result) {
      chart = result['chart'];
      data = result['data'];
      if (chart == 'line') {
        new Morris.Line(data);
      } else if (chart == 'bar') {
        new Morris.Bar(data);
      }
    }
  )
}

$(document).ready(function(){
  $("#generate").click(function(){
    report = ReportChart("{% url 'reportlab:generate_chart' 2 %}");
    report.getChart();
  }
});