Wijmo 5 - FlexGrid CustomFilter Popup

HTML

<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<link rel="stylesheet" href="http://cdn.wijmo.com/5.latest/styles/wijmo.min.css">
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.input.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.grid.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/controls/wijmo.grid.filter.min.js"></script>
<script src="http://cdn.wijmo.com/5.latest/interop/angular/wijmo.angular.min.js"></script>
<!-- mark this as an Angular application and give it a controller -->
<div ng-app="app" ng-controller="appCtrl" class="container">
  <wj-flex-grid control="grid" items-source="data" allow-resizing="Both">
  </wj-flex-grid>

<wj-popup control="customFilter" show-trigger=0 >
  <h1>
    Custom Filter
  </h1>
  <button class="wj-hide-ok" ng-click="applyFilter()">
  Apply
  </button>
  <button class="wj-hide-ok" ng-click='removeFilter()'>
  Remove
  </button>
  <button class="wj-hide-ok">
  Close
  </button>
</wj-popup>
</div>

CSS

.wj-flexgrid {
  height: 150px; 
  margin-top:10px;
 }
 
 .activeFocus{
   color:red;
 }
 
 .wj-flexchart {
   height: 300px;
 }

JavaScript

// define app, include Wijmo 5 directives
var app = angular.module('app', ['wj']);

// controller
app.controller('appCtrl', function($scope) {
	var filterItem;
  $scope.cols=[];
  // create some random data
  var countries = 'US,Germany,UK,Japan,Italy,Greece'.split(','),
    data = [];
  for (var i = 0; i < countries.length; i++) {
    data.push({
      country: countries[i],
      downloads: Math.round(Math.random() * 20000),
      sales: Math.random() * 10000,
      expenses: Math.random() * 5000
    });
  }
	
  $scope.applyFilter=function(){
    var colNum=filterItem.parentNode.parentNode['wj-cell-index'].col;
    var binding=$scope.grid.columns[colNum].binding;
    if($scope.cols.indexOf(binding)<0){
    	$scope.cols.push(binding);
    }
    console.log('filter applied');
    $scope.grid.refresh();
  }
  
  $scope.removeFilter=function(){
    var colNum=filterItem.parentNode.parentNode['wj-cell-index'].col;
    var binding=$scope.grid.columns[colNum].binding;
    if($scope.cols.indexOf(binding)>-1){
    	$scope.cols.splice($scope.cols.indexOf(binding),1);
    }
    console.log('filter removed');
    $scope.grid.refresh();
  }
  
  // expose data as a CollectionView to get events
  $scope.data = new wijmo.collections.CollectionView(data);
  
  $scope.$watch("grid",function(){
  	var grid= $scope.grid;
    if(grid){
    	grid.columnHeaders.rows.defaultSize=40;
      //add tooltip and highlight the filter icon
      grid.updatedLayout.addHandler((s,e)=>{
      	//get filter icons
      	var elemList=s.hostElement.querySelectorAll('.wj-glyph-filter');
        elemList.forEach((el)=>{
        	//get binding accociated with column
          var cell=el.parentNode.parentNode;
          var colNum=cell['wj-cell-index'].col;
          var binding=s.columns[colNum].binding;
          
          var lineBR=document.createElement('br');
          cell.style.height="100px";
          cell.insertBefore(lineBR,cell.firstChild);
          var...