text: 
  var launchSuccess ;
  var landSuccess;
  var launchYear;
  var launchYearState; 
  var Manager;
  $(document).ready(function(){
    
      // just for 100 data
       
      
      $("#loader").show();  
      fetch("https://api.spacexdata.com/v3/launches?limit=100") 
      .then(function(result) {
          return result.json();
      }).then(function(data){
          console.log(data);
          Data = data;
          $("#loader").hide();
          insertData(data);
          launchSuccess=false;
          landSuccess = false;
          launchYear = null;
          $('#filter_launch_false').addClass('disabled');
          $('#filter_landing_false').addClass('disabled'); 
          
          
          setTimeout(function()
          {
           
            Manager =  new Window.filterManager(new Window.target());
  
             
  
            Manager.setFilter(new Window.launchFilter());
            Manager.setFilter(new Window.landFilter());
            Manager.setFilter(new Window.yearFilter());
  
            console.log(Manager);
            
            attachListener();
  
  
          },1000)
         
          
      })
      .catch(function(err) {
          // This is where you run code if its returns any errors
          console.log("error occured "+err);
      }); 
  
      
      function attachListener(){
         // added listener to the filters
  
          $("a").click(function(){
             var id = $(this)[0].id; 
             console.log(id);
             if(id=="filter_launch_true")
             { 
             
              if(launchSuccess==true)
                return ;
                $('#filter_launch_false').removeClass("disabled");
                $('#filter_launch_true').addClass("disabled"); 
  
                launchSuccess = true;    
               
                 
                let obj = {launchSuccess,landSuccess,launchYear};
                 Manager.filterRequest(obj);
               
  
  
  
             }
             else if(id=="filter_launch_false")
             { 
               if(launchSuccess==false)
                  return ;
                  $('#filter_launch_true').removeClass("disabled");
                  $('#filter_launch_false').addClass("disabled"); 
                  launchSuccess=false;
                  
                  let obj = {launchSuccess,landSuccess,launchYear};
                  Manager.filterRequest(obj);
               // filterdata       
        
             }
             else if(id=="filter_landing_true")
             {
                 if(landSuccess==true)
                   return ;
                   $('#filter_landing_false').removeClass("disabled");
                   $('#filter_landing_true').addClass("disabled"); 
  
                  landSuccess=true;
  
               
                let obj = {launchSuccess,landSuccess,launchYear};
                Manager.filterRequest(obj);
  
  
                 // filter data  
             }
             else if(id == "filter_landing_false")
             {
                  if(landSuccess==false)
                      return ;
                      $('#filter_landing_true').removeClass("disabled");
                      $('#filter_landing_false').addClass("disabled");  
                    landSuccess=false;  
                   
                   let obj = {launchSuccess,landSuccess,launchYear};
                   Manager.filterRequest(obj);
  
             }
             else
             {  
  
                let arr = id.split("_");
                if(launchYear==arr[1])
                   return;
                if(launchYear == null)
                  {
                    launchYearState = $(this);
                    launchYearState.addClass("disabled");
                  } 
                else
                   {
                      launchYearState.removeClass("disabled");
                      launchYearState = $(this);
                      launchYearState.addClass("disabled");
  
                   }   
                launchYear=arr[1];
              
               
               let obj = {launchSuccess,landSuccess,launchYear};
               Manager.filterRequest(obj);
  
  
              }     
          });
      }
      function insertData(data)
      {   
          $("#data_inserted").empty();
          for(var i=0;i<data.length;i++)
          { 
            var mission_id = data[i].mission_id;
            var land_succ ;
            var img=null;
            if(mission_id==undefined)
               mission_id="Not Decided Yet"; 
  
            if(data[i].rocket && data[i].rocket.first_stage.cores[0].land_success)
               land_succ = data[i].rocket.first_stage.cores[0].land_success;
            else
               land_succ="Not Known";
            
           if(data[i].links.mission_patch_small!=null)
              img = data[i].links.mission_patch_small;
           else
              img = "img/download.jpg";   
               
                    
  
            var str = '<div class="col-md-3 col-sm-6 mb-2">'+
                        '<div class="card mb-4" style="height:600px">'+
                          '<img class="card-img-top" src="'+img+'"alt="img/download.jpg">'+
                          '<div class="card-body">'+
                              '<h6 style="color:blue" class="card-title" style="text-decoration-color: lightskyblue">'+data[i].mission_name+" #"+data[i].flight_number+'</h6>'+
                          '<p class="card-text"><strong>Mission ids: </strong><span>'+mission_id+'</span></p>'+
                          '<p class="card-text"><strong>Launch year: </strong><span>'+data[i].launch_year+'</span></p>'+
                          '<p class="card-text"><strong>Successful launch: </strong><span>'+data[i].launch_success+'</span></p>'+
                          '<p class="card-text"><strong>Successful landing: </strong><span>'+land_succ+'</span></p>'+   
                         '</div>'+
                        '</div>'+ 
                      '</div>';
                      $("#data_inserted").append(str);          
          }
      }
  
      
      
      
     
    
    });
  
  //   mission_patch_small