Dynamically Move List Collector Options in ServiceNow

For basic information go to List Collector. My requirement was to populate List Collector dynamically on change of requested for.

Solution: List Collector or slashbucket stores values on basis of index values of left side options and index values in a list should be sorted.

var varName = 'u_app_name';
  var leftBucket = gel(varName + '_select_0');
  var rightBucket = gel(varName + '_select_1');
  var allOptions = leftBucket.options;
  
//on requested for change first clear rightBucket
  while(rightBucket.firstChild) {
                if(rightBucket.firstChild != null && rightBucket.firstChild != '') {
                    rightBucket.removeChild(rightBucket.firstChild);
                }
            } 
   
   //Get all the options from custom table
  var grApp=new GlideRecord('u_swo_application_list');
  grApp.query();
  
  while(grApp.next())
   {
   var exist=false;
   for(var i=0;i    {
    if(allOptions[i].value==grApp.sys_id)
     {
     exist=true;
    }
   }
   if(!exist){
   //add option to right side bucket
    var option = document.createElement("option");
    option.value = grApp.sys_id;
    option.text = grApp.u_application_name;
    leftBucket.add(option);
   }
  }
  sortSelect(leftBucket);
  allOptions = leftBucket.options;
  
  var selectedIDs =[];// new Array();
  
//custom table where storing right side slashbucket options   var gr=new GlideRecord('u_swo_leaver_and_joiner');
// caller is requested for value i.e sys_id
  gr.addQuery('u_requested_for.sys_id',caller);
  gr.addQuery('u_access',true);
  gr.query();
  var index=0;
  while(gr.next())
   {
   
   //selectedIDs[index]=index;//gr.u_application;
   for(var j=0;j    {
    
    if(allOptions[j].value==gr.u_application)
     {
     //insert index value only
     selectedIDs[index]=j;
     index++;
     break;
    }
   }
  }
//sort array
   selectedIDs.sort();
  moveSelectedOptions(selectedIDs, leftBucket, rightBucket,'-None-');
  sortSelect(rightBucket);