Lazy load grouping in React Grid component

8 Dec 202324 minutes to read

In React, lazy loading refers to the technique of loading data dynamically when they are needed, instead of loading everything upfront. Lazy loading can significantly improve the performance of your application by reducing the initial load time.

Lazy load grouping in Syncfusion Grid allows you to load and display grouped data efficiently by fetching only the required data on demand. This feature is useful when dealing with large datasets where loading all the data at once might affect performance. The Grid will render only the initial level caption rows in the collapsed state at grouping. The child rows of each caption will be fetched in on demand and render in the Grid when you expand the caption row.

To enable this feature, need to set the groupSettings.enableLazyLoading property to true.

The following example demonstrates how to enable the lazy load grouping feature by setting groupSettings.enableLazyLoading property.

App.jsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, Page, LazyLoadGroup, Inject } from '@syncfusion/ej2-react-grids';
import * as React from 'react';
import { data } from './datasource';
function App() {
    const groupOptions = {
        enableLazyLoading: true,
        columns: ['ProductName', 'CustomerName']
    };
    return (<div>
    <GridComponent dataSource={data} allowPaging={true} allowGrouping={true} groupSettings={groupOptions}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120'/>
        <ColumnDirective field='ProductName' headerText='Product Name' width='160'/>
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120'/>
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160'/>
      </ColumnsDirective>
      <Inject services={[Page, Group, LazyLoadGroup]}/>
    </GridComponent></div>);
}
;
export default App;

App.tsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, Page, LazyLoadGroup, GroupSettingsModel, Inject } from '@syncfusion/ej2-react-grids'
import * as React from 'react';
import { data } from './datasource';

function App() {
  const groupOptions: GroupSettingsModel = {
    enableLazyLoading: true,
    columns: ['ProductName', 'CustomerName']
  }
  return (<div>
    <GridComponent dataSource={data} allowPaging={true} allowGrouping={true} groupSettings={groupOptions}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120' />
        <ColumnDirective field='ProductName' headerText='Product Name' width='160' />
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120' />
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160' />
      </ColumnsDirective>
      <Inject services={[Page, Group, LazyLoadGroup]} />
    </GridComponent></div>)
};
export default App;

datasource.jsx

export let data = createLazyLoadData();
function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

datasource.tsx

export let data: Object[] = createLazyLoadData();

function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

Handling the lazy load grouping at server-side

When using the lazy load grouping feature of the Grid, you can use the UrlAdaptor of DataManager when binding remote data to handle the lazy load grouping at the server-side. Along with the default server request, this feature will additionally send the following details to handle the lazy load grouping:

Property Name	Description
isLazyLoad	Used to differentiate the default grouping and lazy load grouping
onDemandGroupInfo	Contains the details of expanded caption row grouping level, skip, take and filter query of the child records

In the server-side, you can bind these details with the isLazyLoad and onDemandGroupInfo parameters in the DataManagerRequest model. Please refer to the below screenshots.

The following code example describes lazy load grouping being handled on the server-side along with other grid actions.

public IActionResult UrlDatasource([FromBody] DataManagerRequest dm)
{
    IEnumerable groupedData = null;
    IEnumerable<Customers> DataSource = customers;
    DataOperations operation = new DataOperations();

    if (dm.Search != null && dm.Search.Count > 0)
    {
        DataSource = operation.PerformSearching(DataSource, dm.Search);  //Search
    }
    if (dm.Where != null && dm.Where.Count > 0) //Filtering
    {
        DataSource = operation.PerformFiltering(DataSource, dm.Where, dm.Where[0].Operator);
    }
    int count = DataSource.Cast<Customers>().Count();
    if (dm.Sorted != null && dm.Sorted.Count > 0) //Sorting
    {
        DataSource = operation.PerformSorting(DataSource, dm.Sorted);
    }   
    if (dm.IsLazyLoad == false && dm.Skip != 0)
    {
        DataSource = operation.PerformSkip(DataSource, dm.Skip); // Paging
    }
    if (dm.IsLazyLoad == false && dm.Take != 0)
    {
        DataSource = operation.PerformTake(DataSource, dm.Take);
    }
    if (dm.IsLazyLoad)
    {
        groupedData = operation.PerformGrouping<Customers>(DataSource, dm); // Lazy load grouping
        if (dm.OnDemandGroupInfo != null && dm.Group.Count() == dm.OnDemandGroupInfo.Level)
        {
            count = groupedData.Cast<Customers>().Count();
        }
        else
        {
            count = groupedData.Cast<Group>().Count();
        }
        groupedData = operation.PerformSkip(groupedData, dm.OnDemandGroupInfo == null ? dm.Skip : dm.OnDemandGroupInfo.Skip);
        groupedData = operation.PerformTake(groupedData, dm.OnDemandGroupInfo == null ? dm.Take : dm.OnDemandGroupInfo.Take);
    }
return dm.RequiresCounts ? Json(new { result = groupedData == null ? DataSource : groupedData, count = count }) : Json(DataSource);
}

Lazy load grouping with infinite scrolling

Lazy loading grouping with infinite scrolling is a valuable feature in scenarios where there is a need to present grouped data, efficiently handle large datasets, and ensure a seamless experience. This feature enables loading data on demand as the interface is interacted with, ensuring optimal performance and responsiveness while effectively managing and presenting large grouped datasets

How lazy load grouping with infinite scrolling works

1. When you enable lazy load grouping with infinite scrolling, the Grid initially renders only the top-level caption rows in a collapsed state.

2. The child rows associated with each group caption are loaded and rendered in the Grid only when you expand the corresponding caption row.

3. Infinite scrolling enables the Grid to load additional data as the user scrolls to the end of the scrollbar.

To enable this feature, you need to set the groupSettings.enableLazyLoading and enableInfiniteScrolling properties to true.

The following example demonstrates how to enable the lazy load grouping with infinite scrolling feature using the groupSettings.enableLazyLoading and enableInfiniteScrolling properties.

App.jsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, InfiniteScroll, LazyLoadGroup, Inject } from '@syncfusion/ej2-react-grids';
import * as React from 'react';
import { data } from './datasource';
function App() {
    const groupOptions = {
        enableLazyLoading: true,
        columns: ['ProductName', 'CustomerName']
    };
    return (<div>
    <GridComponent dataSource={data} allowGrouping={true} groupSettings={groupOptions} height={315} enableInfiniteScrolling={true}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120'/>
        <ColumnDirective field='ProductName' headerText='Product Name' width='160'/>
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120'/>
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160'/>
      </ColumnsDirective>
      <Inject services={[Group, LazyLoadGroup, InfiniteScroll]}/>
    </GridComponent></div>);
}
;
export default App;

App.tsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, InfiniteScroll, LazyLoadGroup, GroupSettingsModel, Inject } from '@syncfusion/ej2-react-grids'
import * as React from 'react';
import { data } from './datasource';

function App() {
  const groupOptions: GroupSettingsModel = {
    enableLazyLoading: true,
    columns: ['ProductName', 'CustomerName']
  };
  return (<div>
    <GridComponent dataSource={data} allowGrouping={true} groupSettings={groupOptions} height={315} enableInfiniteScrolling={true}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120' />
        <ColumnDirective field='ProductName' headerText='Product Name' width='160' />
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120' />
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160' />
      </ColumnsDirective>
      <Inject services={[Group, LazyLoadGroup, InfiniteScroll]} />
    </GridComponent></div>)
};
export default App;

datasource.jsx

export let data = createLazyLoadData();
function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

datasource.tsx

export let data: Object[] = createLazyLoadData();

function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

• The enableInfiniteScrolling property is optional and can be set to true or false based on the requirement.
• When enabling the enableInfiniteScrolling feature, it is necessary to define the height property.

Lazy load grouping with virtual scrolling

The lazy load grouping with virtual scrolling feature in the Syncfusion React Grid allows you to efficiently present and analyze large grouped datasets. This feature optimizes performance, reduces initial load time, and provides smooth scrolling through the dataset.

How lazy load grouping with virtual scrolling works

1. When you enable lazy load grouping with virtual scrolling, the Grid renders only the initial level caption rows in a collapsed state.

2. The child rows associated with each group caption are loaded and rendered in the Grid only when you expand the respective caption row.

3. Virtual scrolling allows the Grid to load and display a buffered set of records while scrolling vertically.

To enable this feature, you need to set the groupSettings.enableLazyLoading and enableVirtualization properties to true.

The following example demonstrates how to enable the lazy load grouping with virtual scrolling feature using the groupSettings.enableLazyLoading and enableVirtualization properties.

App.jsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, VirtualScroll, LazyLoadGroup, GroupSettingsModel, Inject } from '@syncfusion/ej2-react-grids'
import * as React from 'react';
import { data } from './datasource';

function App() {
  const groupOptions = {
    enableLazyLoading: true,
    columns: ['ProductName', 'CustomerName']
  };
  return (<div>
    <GridComponent dataSource={data} allowGrouping={true} groupSettings={groupOptions} height={315} enableVirtualization={true}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120' />
        <ColumnDirective field='ProductName' headerText='Product Name' width='160' />
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120' />
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160' />
      </ColumnsDirective>
      <Inject services={[Group, LazyLoadGroup, VirtualScroll]} />
    </GridComponent></div>)
};
export default App;

App.tsx

import { ColumnDirective, ColumnsDirective } from '@syncfusion/ej2-react-grids';
import { GridComponent, Group, VirtualScroll, LazyLoadGroup, GroupSettingsModel, Inject } from '@syncfusion/ej2-react-grids'
import * as React from 'react';
import { data } from './datasource';

function App() {
  const groupOptions: GroupSettingsModel = {
    enableLazyLoading: true,
    columns: ['ProductName', 'CustomerName']
  };
  return (<div>
    <GridComponent dataSource={data} allowGrouping={true} groupSettings={groupOptions} height={315} enableVirtualization={true}>
      <ColumnsDirective>
        <ColumnDirective field='OrderID' headerText='Order ID' textAlign="Right" width='120' />
        <ColumnDirective field='ProductName' headerText='Product Name' width='160' />
        <ColumnDirective field='ProductID' headerText='Product ID' textAlign="Right" width='120' />
        <ColumnDirective field='CustomerName' headerText='Customer Name' width='160' />
      </ColumnsDirective>
      <Inject services={[Group, LazyLoadGroup, VirtualScroll]} />
    </GridComponent></div>)
};
export default App;

datasource.jsx

export let data = createLazyLoadData();
function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

datasource.tsx

export let data: Object[] = createLazyLoadData();

function createLazyLoadData() {
    var lazyLoadData = [];
    var customerid = ['VINET', 'TOMSP', 'HANAR', 'VICTE', 'SUPRD', 'HANAR', 'CHOPS', 'RICSU', 'WELLI', 'HILAA', 'ERNSH', 'CENTC',
        'OTTIK', 'QUEDE', 'RATTC', 'ERNSH', 'FOLKO', 'BLONP', 'WARTH', 'FRANK', 'GROSR', 'WHITC', 'WARTH', 'SPLIR', 'RATTC', 'QUICK', 'VINET',
        'MAGAA', 'TORTU', 'MORGK', 'BERGS', 'LEHMS', 'BERGS', 'ROMEY', 'ROMEY', 'LILAS', 'LEHMS', 'QUICK', 'QUICK', 'RICAR', 'REGGC', 'BSBEV',
        'COMMI', 'QUEDE', 'TRADH', 'TORTU', 'RATTC', 'VINET', 'LILAS', 'BLONP', 'HUNGO', 'RICAR', 'MAGAA', 'WANDK', 'SUPRD', 'GODOS', 'TORTU',
        'OLDWO', 'ROMEY', 'LONEP', 'ANATR', 'HUNGO', 'THEBI', 'DUMON', 'WANDK', 'QUICK', 'RATTC', 'ISLAT', 'RATTC', 'LONEP', 'ISLAT', 'TORTU',
        'WARTH', 'ISLAT', 'PERIC', 'KOENE', 'SAVEA', 'KOENE', 'BOLID', 'FOLKO', 'FURIB', 'SPLIR', 'LILAS', 'BONAP', 'MEREP', 'WARTH', 'VICTE',
        'HUNGO', 'PRINI', 'FRANK', 'OLDWO', 'MEREP', 'BONAP', 'SIMOB', 'FRANK', 'LEHMS', 'WHITC', 'QUICK', 'RATTC', 'FAMIA'];
    var product = ['Chai', 'Chang', 'Aniseed Syrup', 'Chef Anton\'s Cajun Seasoning', 'Chef Anton\'s Gumbo Mix', 'Grandma\'s Boysenberry Spread',
        'Uncle Bob\'s Organic Dried Pears', 'Northwoods Cranberry Sauce', 'Mishi Kobe Niku', 'Ikura', 'Queso Cabrales', 'Queso Manchego La Pastora', 'Konbu',
        'Tofu', 'Genen Shouyu', 'Pavlova', 'Alice Mutton', 'Carnarvon Tigers', 'Teatime Chocolate Biscuits', 'Sir Rodney\'s Marmalade', 'Sir Rodney\'s Scones',
        'Gustaf\'s Knäckebröd', 'Tunnbröd', 'Guaraná Fantástica', 'NuNuCa Nuß-Nougat-Creme', 'Gumbär Gummibärchen', 'Schoggi Schokolade', 'Rössle Sauerkraut',
        'Thüringer Rostbratwurst', 'Nord-Ost Matjeshering', 'Gorgonzola Telino', 'Mascarpone Fabioli', 'Geitost', 'Sasquatch Ale', 'Steeleye Stout', 'Inlagd Sill',
        'Gravad lax', 'Côte de Blaye', 'Chartreuse verte', 'Boston Crab Meat', 'Jack\'s New England Clam Chowder', 'Singaporean Hokkien Fried Mee', 'Ipoh Coffee',
        'Gula Malacca', 'Rogede sild', 'Spegesild', 'Zaanse koeken', 'Chocolade', 'Maxilaku', 'Valkoinen suklaa', 'Manjimup Dried Apples', 'Filo Mix', 'Perth Pasties',
        'Tourtière', 'Pâté chinois', 'Gnocchi di nonna Alice', 'Ravioli Angelo', 'Escargots de Bourgogne', 'Raclette Courdavault', 'Camembert Pierrot', 'Sirop d\'érable',
        'Tarte au sucre', 'Vegie-spread', 'Wimmers gute Semmelknödel', 'Louisiana Fiery Hot Pepper Sauce', 'Louisiana Hot Spiced Okra', 'Laughing Lumberjack Lager', 'Scottish Longbreads',
        'Gudbrandsdalsost', 'Outback Lager', 'Flotemysost', 'Mozzarella di Giovanni', 'Röd Kaviar', 'Longlife Tofu', 'Rhönbräu Klosterbier', 'Lakkalikööri', 'Original Frankfurter grüne Soße'];
    var customername = ['Maria', 'Ana Trujillo', 'Antonio Moreno', 'Thomas Hardy', 'Christina Berglund', 'Hanna Moos', 'Frédérique Citeaux', 'Martín Sommer', 'Laurence Lebihan', 'Elizabeth Lincoln',
        'Victoria Ashworth', 'Patricio Simpson', 'Francisco Chang', 'Yang Wang', 'Pedro Afonso', 'Elizabeth Brown', 'Sven Ottlieb', 'Janine Labrune', 'Ann Devon', 'Roland Mendel', 'Aria Cruz', 'Diego Roel',
        'Martine Rancé', 'Maria Larsson', 'Peter Franken', 'Carine Schmitt', 'Paolo Accorti', 'Lino Rodriguez', 'Eduardo Saavedra', 'José Pedro Freyre', 'André Fonseca', 'Howard Snyder', 'Manuel Pereira',
        'Mario Pontes', 'Carlos Hernández', 'Yoshi Latimer', 'Patricia McKenna', 'Helen Bennett', 'Philip Cramer', 'Daniel Tonini', 'Annette Roulet', 'Yoshi Tannamuri', 'John Steel', 'Renate Messner', 'Jaime Yorres',
        'Carlos González', 'Felipe Izquierdo', 'Fran Wilson', 'Giovanni Rovelli', 'Catherine Dewey', 'Jean Fresnière', 'Alexander Feuer', 'Simon Crowther', 'Yvonne Moncada', 'Rene Phillips', 'Henriette Pfalzheim',
        'Marie Bertrand', 'Guillermo Fernández', 'Georg Pipps', 'Isabel de Castro', 'Bernardo Batista', 'Lúcia Carvalho', 'Horst Kloss', 'Sergio Gutiérrez', 'Paula Wilson', 'Maurizio Moroni', 'Janete Limeira', 'Michael Holz',
        'Alejandra Camino', 'Jonas Bergulfsen', 'Jose Pavarotti', 'Hari Kumar', 'Jytte Petersen', 'Dominique Perrier', 'Art Braunschweiger', 'Pascale Cartrain', 'Liz Nixon', 'Liu Wong', 'Karin Josephs', 'Miguel Angel Paolino',
        'Anabela Domingues', 'Helvetius Nagy', 'Palle Ibsen', 'Mary Saveley', 'Paul Henriot', 'Rita Müller', 'Pirkko Koskitalo', 'Paula Parente', 'Karl Jablonski', 'Matti Karttunen', 'Zbyszek Piestrzeniewicz'];
    var customeraddress = ['507 - 20th Ave. E.\r\nApt. 2A', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '4726 - 11th Ave. N.E.', '7 Houndstooth Rd.', '59 rue de l\'Abbaye', 'Luisenstr. 48', '908 W. Capital Way', '722 Moss Bay Blvd.', '4110 Old Redmond Rd.', '14 Garrett Hill', 'Coventry House\r\nMiner Rd.', 'Edgeham Hollow\r\nWinchester Way',
        '7 Houndstooth Rd.', '2817 Milton Dr.', 'Kirchgasse 6', 'Sierras de Granada 9993', 'Mehrheimerstr. 369', 'Rua da Panificadora, 12', '2817 Milton Dr.', 'Mehrheimerstr. 369'];
    var quantityperunit = ['10 boxes x 20 bags', '24 - 12 oz bottles', '12 - 550 ml bottles', '48 - 6 oz jars', '36 boxes', '12 - 8 oz jars', '12 - 1 lb pkgs.', '12 - 12 oz jars', '18 - 500 g pkgs.', '12 - 200 ml jars',
        '1 kg pkg.', '10 - 500 g pkgs.', '2 kg box', '40 - 100 g pkgs.', '24 - 250 ml bottles', '32 - 500 g boxes', '20 - 1 kg tins', '16 kg pkg.', '10 boxes x 12 pieces', '30 gift boxes', '24 pkgs. x 4 pieces', '24 - 500 g pkgs.', '12 - 250 g pkgs.',
        '12 - 355 ml cans', '20 - 450 g glasses', '100 - 250 g bags'];
    var OrderID = 10248;
    for (var i = 0; i < 20000; i++) {
        lazyLoadData.push({
            'OrderID': OrderID + i,
            'CustomerID': customerid[Math.floor(Math.random() * customerid.length)],
            'CustomerName': customername[Math.floor(Math.random() * customername.length)],
            'CustomerAddress': customeraddress[Math.floor(Math.random() * customeraddress.length)],
            'ProductName': product[Math.floor(Math.random() * product.length)],
            'ProductID': i,
            'Quantity': quantityperunit[Math.floor(Math.random() * quantityperunit.length)]
        });
    }
    return lazyLoadData;
}

When using the enableVirtualization feature, it is necessary to define the height property.

Limitations for lazy load grouping

• Due to the element height limitation in browsers, the maximum number of records loaded by the grid is limited due to the browser capability.
• Lazy load grouping is only supported by the UrlAdaptor and JsonAdaptor adaptors.
• Lazy load grouping is not compatible with the following features
  • Batch editing
  • Row template
  • Print
  • Row drag and drop in collapsed group
  • ExpandAll method
  • Column virtualization
  • Hierarchical Grid
  • Detail Template
  • Row and Cell Spanning
• Programmatic selection is not supported in lazy load grouping.
• Drag selection, Cell selection (box and flow), Row Selection is not working in collapsed state.
• Clipboard is not support when the groups are in collapsed state.