Remote Operations
We recommend server-side data processing for large datasets. The ODataStore supports server-side paging, filtering, and sorting. DevExtreme provides extensions that help implement data processing for ASP.NET and PHP servers. You can also use the third-party extension for MongoDB. If these extensions do not suit your data source, implement server-side data processing manually according to the protocol described in the Custom Sources article.
Specify the remoteOperations property to notify the DataGrid of the server's data processing operations.
jQuery
$(function() { $("#dataGridContainer").dxDataGrid({ // ... remoteOperations: { filtering: true, paging: true, sorting: true, groupPaging: true, grouping: true, summary: true } }); });
Angular
<dx-data-grid ... > <dxo-remote-operations [filtering]="true" [paging]="true" [sorting]="true" [summary]="true" [grouping]="true" [groupPaging]="true"> </dxo-remote-operations> </dx-data-grid>
import { DxDataGridModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxDataGridModule ], // ... })
Vue
<template> <DxDataGrid ... > <DxRemoteOperations :filtering="true" :paging="true" :sorting="true" :summary="true" :grouping="true" :group-paging="true" /> </DxDataGrid> </template> <script> import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DxDataGrid, { DxRemoteOperations } from 'devextreme-vue/data-grid'; export default { components: { DxDataGrid, DxRemoteOperations }, // ... } </script>
React
import React from 'react'; import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DataGrid, { RemoteOperations } from 'devextreme-react/data-grid'; class App extends React.Component { render() { return ( <DataGrid ... > <RemoteOperations filtering={true} paging={true} sorting={true} summary={true} grouping={true} groupPaging={true} /> </DataGrid> ); } } export default App;
Deferred Selection
Use deferred mode to increase the DataGrid's performance when selecting multiple rows at once. In this mode, only the API (for example, the getSelectedRowsData() or getSelectedRowKeys() method) can request the DataGrid data. Assign true to the selection.deferred property to use deferred selection.
jQuery
$(function(){ $("#dataGridContainer").dxDataGrid({ // ... dataSource: { store: { type: "odata", url: "https://js.devexpress.com/Demos/DevAV/odata/Products", key: "Product_ID" } }, selection: { mode: "multiple", allowSelectAll: true, deferred: true } }); });
Angular
<dx-data-grid [dataSource]="dataSource"> <dxo-selection mode="multiple" [allowSelectAll]="true" [deferred]="true"> </dxo-selection> </dx-data-grid>
import { DxDataGridModule } from "devextreme-angular"; import "devextreme/data/odata/store"; // ... export class AppComponent { dataSource = { store: { type: "odata", url: "https://js.devexpress.com/Demos/DevAV/odata/Products", key: "Product_ID" } } } @NgModule({ imports: [ // ... DxDataGridModule ], // ... })
Vue
<template> <DxDataGrid :data-source="store"> <DxSelection mode="multiple" :allow-select-all="true" :deferred="true" /> </DxDataGrid> </template> <script> import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DxDataGrid, { DxSelection } from 'devextreme-vue/data-grid'; import ODataStore from 'devextreme/data/odata/store'; const store = new ODataStore({ url: 'https://js.devexpress.com/Demos/DevAV/odata/Products', key: 'Product_ID' }); export default { components: { DxDataGrid, DxSelection }, data() { return { store } } } </script>
React
import React from 'react'; import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DataGrid, { Selection } from 'devextreme-react/data-grid'; import ODataStore from 'devextreme/data/odata/store'; const store = new ODataStore({ url: 'https://js.devexpress.com/Demos/DevAV/odata/Products', key: 'Product_ID' }); class App extends React.Component { render() { return ( <DataGrid dataSource={store}> <Selection mode="multiple" allowSelectAll={true} deferred={true} /> </DataGrid> ); } } export default App;
The following tasks require using different API in deferred mode:
Setting initial selection
You should use the selectionFilter instead of the selectedRowKeys property to set the initially selected rows in deferred mode. Pass a filter expression to define records that should be selected.
jQuery
JavaScript$(function () { $("#dataGridContainer").dxDataGrid({ // ... selectionFilter: ["Task_Status", "=", "Completed"] }); });
Angular
HTMLTypeScript<dx-data-grid ... [selectionFilter]="['Task_Status', '=', 'Completed']"> </dx-data-grid>
import { DxDataGridModule } from "devextreme-angular"; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxDataGridModule ], // ... })
Vue
App.vue<template> <DxDataGrid ... :selection-filter="['Task_Status', '=', 'Completed']"> </DxDataGrid> </template> <script> // ... </script>
React
App.js// ... class App extends React.Component { selectionFilter = ['Task_Status', '=', 'Completed'];
} export default App;render() { return ( <DataGrid ... defaultSelectionFilter={this.selectionFilter}> </DataGrid> ); }
The DataGrid changes the selectionFilter property's value internally when a user selects a row. You can use the following code to obtain this property's value and send it to the server:
jQuery
JavaScriptfunction sendSelectedRows() { var selectionFilter = dataGridInstance.option("selectionFilter"); $.ajax({ method: "POST", url: "url/to/data/processing/method", data: { filter: (selectionFilter ? JSON.stringify(selectionFilter) : null) } }); }
Angular
TypeScriptimport { ..., ViewChild } from "@angular/core"; import { HttpClient, HttpClientModule } from "@angular/common/http"; import { DxDataGridModule, DxDataGridComponent } from "devextreme-angular"; // ... export class AppComponent { @ViewChild(DxDataGridComponent, { static: false }) dataGrid: DxDataGridComponent; // Prior to Angular 8 // @ViewChild(DxDataGridComponent) dataGrid: DxDataGridComponent; constructor(private httpClient: HttpClient) { } sendSelectedRows() { var selectionFilter = this.dataGrid.instance.option("selectionFilter"); this.httpClient .post("url/to/data/processing/method", "filter: " + (selectionFilter ? JSON.stringify(selectionFilter) : null) ) .subscribe(); } } @NgModule({ imports: [ // ... DxDataGridModule, HttpClientModule ], // ... })
Vue
App.vue<template> <DxDataGrid ... v-model:selection-filter="selectionFilter"> </DxDataGrid> </template> <script> import 'whatwg-fetch'; // ... export default { // ... data() { return { selectionFilter: ['Task_Status', '=', 'Completed'] } }, methods: { sendSelectedRows() { return new Promise((resolve, reject) => { fetch('https://mydomain.com/MyDataService', { method: 'POST', body: JSON.stringify({ filter: this.selectionFilter || null }) }), .then(response => { if (!response.ok) { throw new Error(`HTTP error: ${res.status} ${res.statusText}`); } return response.json(); }) .then(res => { resolve(res); }) .catch(error => { console.error(error); reject(error); }); }); } } } </script>
React
App.jsimport 'whatwg-fetch'; // ... class App extends React.Component { constructor(props) { super(props); this.state = { selectionFilter: ['Task_Status', '=', 'Completed'] } this.handleOptionChange = this.handleOptionChange.bind(this); } handleOptionChange(e) { if(e.fullName === 'selectionFilter') { this.setState({ selectionFilter: e.value }); } } render() { return ( <DataGrid ... selectionFilter={this.state.selectionFilter} onOptionChanged={this.handleOptionChange}> </DataGrid> ); } sendSelectedRows() { return new Promise((resolve, reject) => { fetch('https://mydomain.com/MyDataService', { method: 'POST', body: JSON.stringify({ filter: this.state.selectionFilter || null }) }), .then(response => { if (!response.ok) { throw new Error(`HTTP error: ${res.status} ${res.statusText}`); } return response.json(); }) .then(res => { resolve(res); }) .catch(error => { console.error(error); reject(error); }); }); } } export default App;
Checking whether a row is selected
Use the isRowSelected(data) method to determine whether a row is selected.
Getting the selected rows' data
In deferred mode, the getSelectedRowsData() and getSelectedRowKeys() methods return a native Promise or a jQuery.Promise when you use jQuery. Get the data within the callback function that resolves the Promise. This is data before being processed in the DataSource.
See Also
- key in ArrayStore | CustomStore | LocalStore | ODataStore
Lookup Optimization
As a rule, a lookup column contains IDs from a main data source field but displays human-readable values from its own data source. When the DataGrid first launches, it loads data from both data sources which causes performance to decrease.
You can send the human-readable values from the server as a part of the main data source alongside the IDs (like in this example) to optimize the lookup column. In this case, use the column's calculateDisplayValue property to specify which field provides the human-readable values. With this optimization, the lookup data source is not loaded until a user starts editing the lookup column.
jQuery
$(function () { $("#dataGridContainer").dxDataGrid({ //... columns: [{ caption: "Customer", // "CustomerName" provides human-readable values calculateDisplayValue: "CustomerName", dataField: "CustomerID", lookup: { valueExpr: "CustomerID", displayExpr: "ContactName", dataSource: { store: { // ... key: "CustomerID" } } } }, // ... ] }); });
Angular
<dx-data-grid ...> <dxi-column caption="Customer" dataField="CustomerID" calculateDisplayValue="CustomerName"> <!-- "CustomerName" provides human-readable values --> <dxo-lookup [dataSource]="dataSource" displayExpr="ContactName" valueExpr="CustomerID"> </dxo-lookup> </dxi-column> </dx-data-grid>
import { DxDataGridModule } from "devextreme-angular"; import "devextreme/data/array_store"; // or // import "devextreme/data/odata/store"; // import "devextreme/data/custom_store"; export class AppComponent { dataSource: any; constructor() { this.dataSource = { store: { // ... key: "CustomerID" } } } } @NgModule({ imports: [ // ... DxDataGridModule ], // ... })
Vue
<template> <DxDataGrid ... > <DxColumn caption="Customer" data-field="CustomerID" calculate-display-value="CustomerName"> <!-- "CustomerName" provides human-readable values --> <DxLookup :data-source="lookupDataSourceConfig" display-expr="ContactName" value-expr="CustomerID" /> </DxColumn> </DxDataGrid> </template> <script> import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DxDataGrid, { DxColumn, DxLookup } from 'devextreme-vue/data-grid'; import 'devextreme/data/array_store'; // ===== or ===== // import "devextreme/data/odata/store"; // import "devextreme/data/custom_store"; const lookupDataSourceConfig = { store: { // ... key: 'CustomerID' } } export default { components: { DxDataGrid, DxColumn, DxLookup }, data() { return { lookupDataSourceConfig } } } </script>
React
import React from 'react'; import 'devextreme/dist/css/dx.common.css'; import 'devextreme/dist/css/dx.light.css'; import DataGrid, { Column, Lookup } from 'devextreme-react/data-grid'; import 'devextreme/data/array_store'; // ===== or ===== // import "devextreme/data/odata/store"; // import "devextreme/data/custom_store"; const lookupDataSourceConfig = { store: { // ... key: 'CustomerID' } } class App extends React.Component { render() { return ( <DataGrid ... > <Column caption="Customer" dataField="CustomerID" calculateDisplayValue="CustomerName"> <!-- "CustomerName" provides human-readable values --> <Lookup dataSource={lookupDataSourceConfig} displayExpr="ContactName" valueExpr="CustomerID" /> </Column> </DataGrid> ); } } export default App;
See Also
Data Navigation
We recommend configuring one of the following features for a user to navigate a large dataset:
Pager
The pager allows a user to switch between pages in the dataset. This is the default navigation method.Virtual scrolling
Virtual scrolling allows users to scroll page by page or jump to any page in the dataset. To enable it, set scrolling.mode to "virtual".Infinite scrolling
In this mode, users scroll data page by page, but cannot skip pages. Use this mode if the virtual scrolling mode reduces performance, and navigation via the pager does not suit your case. To enable infinite scrolling, set scrolling.mode to "infinite".
Use the paging.pageSize to specify the number of rows that are loaded at a time. The bigger this value, the fewer requests are sent to the database. However, this increases the data transfer rate. This property is applied regardless of the specified navigation method.
Rendering Optimization
If you work with a large data set, follow the recommendations below to improve rendering performance:
Render only visible rows and columns
The DataGrid renders all rows and columns once it loads data. To improve performance, set the rowRenderingMode and columnRenderingMode properties in the scrolling object to "virtual". In this case, UI elements are only rendered when they come into the viewport. Use virtual row rendering if paging is disabled or the pageSize is higher than the default value. Virtual column rendering should be used in grids with more than 20 columns outside the viewport.Render elements with complex content last
The grid control can render cells with simple content first, and only then proceed to cells with complex content (filter row, command columns, editors and columns with checkboxes). In this case, the control shows content sooner and the app UI can be perceived as more responsive. To load simple content first, use the renderAsync property. You can also enable the same property for individual columns if they use content-heavy cell templates.Prevent columns from adjusting their widths to the content
Do not enable columnAutoWidth property. To further optimize rendering, set a fixed width for all columns. To do this, use a column's width or a component's columnWidth properties to specify the width for each column or all columns, respectively. Note that you should use individual settings because command columns ignore columnWidth.Do not use checkboxes in Boolean columns
The checkbox is the default editor for "Boolean" dataType columns. You can increase rendering speed if you instruct the grid to render text instead. To do this, assign false to the column's showEditorAlways. Use the trueText and falseText properties to specify display strings. The default values are true and false respectively.Implement onCellPrepared instead of cellTemplate for conditional formatting
Due to the design of DevExtreme UI components, onCellPrepared works faster when you need to stylize cells based on a certain condition.
If you have technical questions, please create a support ticket in the DevExpress Support Center.
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