Wijmo CollectionView nullのソート方法

by Wijmo5_jp

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdn.grapecity.com/wijmo/5.latest/styles/wijmo.min.css">
<script src="https://cdn.grapecity.com/wijmo/5.latest/controls/wijmo.min.js"></script>
<script src="https://cdn.grapecity.com/wijmo/5.latest/controls/cultures/wijmo.culture.ja.min.js"></script>
<script src="https://cdn.grapecity.com/wijmo/5.latest/controls/wijmo.grid.min.js"></script>
<div class="container-fluid">
  <label>nullのソート方法
    <select id="sortNulls">
      <option value="Natural">最小値として扱う</option>
      <option value="Last">常に最後に表示</option>
      <option value="First">常に先頭に表示</option>
    </select>
  </label><br>
  <div id="flexGrid"></div>
</div>

CSS

body {
  margin: 50px 0;
}

JavaScript

document.readyState === 'complete' ? init() : window.onload = init;
function init() {
  var view = new wijmo.collections.CollectionView(getData(5), {
    sortNulls: wijmo.collections.SortNulls.Natural
  });
  var flexGrid = new wijmo.grid.FlexGrid('#flexGrid', {
    itemsSource: view,
    columns: [
      { binding: '商品名', width: 200 },
      { binding: '受注日', width: 120 },
      { binding: '金額', format: 'c', width: 100 }
    ]
  });
  document.getElementById('sortNulls').addEventListener('change', function (e) {
    view.sortNulls = e.target.value;
  });
}

var productNames = ['果汁100%オレンジ', '果汁100%グレープ', '果汁100%レモン', '果汁100%ピーチ', 'コーヒーマイルド', 'コーヒービター', 'コーヒーミルク', 'ピリピリビール', 'オタル白ラベル', 'バードワイン'];
function random(max, min) {
  if (!min) min = 0;
  return Math.floor(Math.random() * (max - min)) + min;
}
function randomDate() {
  let date = new Date((new Date()).getFullYear() - 5, 3, 1);
  return wijmo.DateTime.addDays(date, random(365 * 5));
}
function getData(length) {
  let data = [];
  for (let i = 0; i < length; i++) {
    data.push({
      No: i == 2 ? null : i,
      商品名: i == 2 ? null : productNames[random(productNames.length)],
      受注日: i == 2 ? null : randomDate(),
      金額: i == 2 ? null : random(99, 1) * 100,
      値引: i == 2 ? null : random(3) == 0
    });
  }
  return data;
}