The ComboBox supports wrapping nested elements into a group based on different categories. The category of each list item can be mapped through the groupBy field in the data table. The group header is displayed both as inline and fixed headers. The fixed group header content is updated dynamically on scrolling the popup list with its category value.
In the following sample, the vegetables are grouped according on its category using groupBy
field.
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component<{}, {}> {
// define the data with category
private vegetableData: { [key: string]: Object }[] = [
{ Vegetable: 'Cabbage', Category: 'Leafy and Salad', Id: 'item1' },
{ Vegetable: 'Spinach', Category: 'Leafy and Salad', Id: 'item2' },
{ Vegetable: 'Wheat grass', Category: 'Leafy and Salad', Id: 'item3' },
{ Vegetable: 'Yarrow', Category: 'Leafy and Salad', Id: 'item4' },
{ Vegetable: 'Pumpkins', Category: 'Leafy and Salad', Id: 'item5' },
{ Vegetable: 'Chickpea', Category: 'Beans', Id: 'item6' },
{ Vegetable: 'Green bean', Category: 'Beans', Id: 'item7' },
{ Vegetable: 'Horse gram', Category: 'Beans', Id: 'item8' },
{ Vegetable: 'Garlic', Category: 'Bulb and Stem', Id: 'item9' },
{ Vegetable: 'Nopal', Category: 'Bulb and Stem', Id: 'item10' },
{ Vegetable: 'Onion', Category: 'Bulb and Stem', Id: 'item11' }
];
// map the groupBy field with Category column
private fields: object = { groupBy: 'Category', text: 'Vegetable', value: 'Id' };
public render() {
return (
// specifies the tag for render the ComboBox component
<ComboBoxComponent id="comboelement" popupHeight='200px' fields={this.fields} dataSource={this.vegetableData} placeholder="Select a vegetable" />
);
}
}
ReactDOM.render(<App />, document.getElementById('sample'));
<!DOCTYPE html>
<html lang="en">
<head>
<title>Syncfusion React ComboBox</title>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="description" content="Essential JS 2 for React Components" />
<meta name="author" content="Syncfusion" />
<link href="//cdn.syncfusion.com/ej2/ej2-base/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/ej2-react-inputs/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/ej2-react-dropdowns/styles/material.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
<script src="systemjs.config.js"></script>
<style>
#loader {
color: #008cff;
height: 40px;
left: 45%;
position: absolute;
top: 45%;
width: 30%;
}
</style>
</head>
<body>
<div id='sample' style="margin: 40px auto 0; width:250px;">
<div id='loader'>Loading....</div>
</div>
</body>
</html>
The grouping header is also provided with customization option. This allows custom designing using
the groupTemplate
property for both inline and fixed headers as referred here:
Group Template support to ComboBox.