Grouping in EJ2 TypeScript MultiSelect Dropdown

04 Sep 202613 minutes to read

The MultiSelect 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, vegetables are grouped according to their category using the groupBy field.

import { MultiSelect } from '@syncfusion/ej2-dropdowns';
//define the data with category
let 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' }
    ];
//initiate the MultiSelect
let vegetables: MultiSelect = new MultiSelect({
    //set the grouped data to dataSource property
    dataSource: vegetableData,
    // map the groupBy field with category column
    fields: { groupBy: 'category', text: 'vegetable', value: 'id' },
    // set the placeholder to the MultiSelect input
    placeholder: "Select vegetables",
    // Set the popup list height
    popupHeight: '200px'
});
//render the MultiSelect component
vegetables.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/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>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

HTML select

The MultiSelect also supports grouping list items by initializing the <select> element with <optgroup> tags. The nested items are wrapped based on the <optgroup> element present in the <select> element.

    <select id="selectElement">
        <optgroup label="Beans">
            <option value="1">Chickpea</option>
            <option value="2">Green bean</option>
            <option value="3">Horse gram</option>
        </optgroup>
        <optgroup label="Leafy and Salad">
            <option value="4">Spinach</option>
            <option value="5" selected="selected">Cabbage</option>
            <option value="6">Wheat grass</option>
        </optgroup>
    </select>

import { MultiSelect } from '@syncfusion/ej2-dropdowns';

    // initialize MultiSelect component
    let msObject: MultiSelect = new MultiSelect({
        placeholder:"Select vegetables"
    });

    // render initialized MultiSelect
    msObject.appendTo('#selectElement');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
     <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/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>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <select id="selectElement">
            <optgroup label="Beans">
                <option value="1">Chickpea</option>
                <option value="2">Green bean</option>
                <option value="3">Horse gram</option>
            </optgroup>
            <optgroup label="Leafy and Salad">
                <option value="4" selected="selected">Cabbage</option>
                <option value="5">Spinach</option>
                <option value="6">Wheat grass</option>
            </optgroup>
            
        </select>
    </div>

</body>

</html>

Customization

The grouping header can also be customized for both inline and fixed headers using the groupTemplate property.

Grouping with CheckBox

Previously, there was no checkbox for group headers. Now, this feature allows you to render a checkbox in the group header to select the group items in a single selection. You can enable this feature by setting the enableGroupCheckBox property value to true and the mode property to CheckBox.

Inject the CheckBoxSelection module into the MultiSelect to use the checkbox.

import { MultiSelect, CheckBoxSelection } from '@syncfusion/ej2-dropdowns';

MultiSelect.Inject(CheckBoxSelection);

//define the array of complex data
let sportsData: { [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' }
];

//initiate the MultiSelect
let msObject: MultiSelect = new MultiSelect({
    // bind the sports Data to datasource property
    dataSource: sportsData,
    // maps the appropriate column to fields property
    fields: { groupBy: 'category', text: 'vegetable', value: 'id' },
    //set the placeholder to MultiSelect input
    placeholder:"Select vegetables",
    // set the type of mode for checkbox to visualized the checkbox added in li element.
    mode: 'CheckBox',
    // set true for enable the selectAll support.
    showSelectAll: true,
    // set value for allowFiltering as true
    allowFiltering: true,
    // set placeholder to filterbar
    filterBarPlaceholder: "Search Vegetables",
    // set true for enableGroupCheckBox property
    enableGroupCheckBox: true
});
//render the component
msObject.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/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>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

See Also