SignalR Service
This example demonstrates real-time data update in a DataGrid bound to a SignalR service. Access to the service is configured in a CustomStore.
The CustomStore fetches the remote dataset at launch and keeps its local copy. Whenever the remote dataset changes, the server calls a client-side function that updates the local copy of the dataset (updateStockPrices in this demo). This function uses the store's push(changes) method.
For server-side configuration, refer to the ASP.NET MVC version of this demo.
For more information about integration with push services, refer to the following help topic: Integration with Push Services.
NOTE: Data used in this demo is for demonstration purposes only.
Feel free to share demo-related thoughts here.
If you have technical questions, please create a support ticket in the DevExpress Support Center.
If you have technical questions, please create a support ticket in the DevExpress Support Center.
Thank you!
We appreciate your feedback.
We appreciate your feedback.
import React from 'react';
import DataGrid, {
Column
} from 'devextreme-react/data-grid';
import CustomStore from 'devextreme/data/custom_store';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import PriceCell from './PriceCell.js';
import ChangeCell from './ChangeCell.js';
class App extends React.Component {
constructor(props) {
super(props);
this.state = { connectionStarted: false, dataSource: null };
var hubConnection = new HubConnectionBuilder()
.withUrl('https://js.devexpress.com/Demos/NetCore/liveUpdateSignalRHub', {
skipNegotiation: true,
transport: HttpTransportType.WebSockets
})
.build();
var store = new CustomStore({
load: () => hubConnection.invoke('getAllStocks'),
key: 'symbol'
});
hubConnection
.start()
.then(() => {
hubConnection.on('updateStockPrice', (data) => {
store.push([{ type: 'update', key: data.symbol, data: data }]);
});
this.setState({ connectionStarted: true, dataSource: store });
});
}
render() {
return (
<div>
{this.state.connectionStarted &&
(<DataGrid
id="gridContainer"
dataSource={this.state.dataSource}
showBorders={true}
repaintChangesOnly={true}
highlightChanges={true}
>
<Column dataField="lastUpdate" dataType="date" width={115} format="longTime" />
<Column dataField="symbol" />
<Column dataField="price" dataType="number" format="#0.####" cellRender={PriceCell} />
<Column dataField="change" dataType="number" width={140} format="#0.####" cellRender={ChangeCell} />
<Column dataField="dayOpen" dataType="number" format="#0.####" />
<Column dataField="dayMin" dataType="number" format="#0.####" />
<Column dataField="dayMax" dataType="number" format="#0.####" />
</DataGrid>)
}
</div>
);
}
}
export default App;
import React from 'react';
export default function ChangeCell(cell) {
return (
<div className={cell.data.change > 0 ? 'inc' : 'dec' }>
<span className="current-value">{cell.text}</span>
<span className="arrow"></span>
<span className="diff">{cell.data.percentChange.toFixed(2)}%</span>
</div>
);
}
import React from 'react';
export default function DiscountCell(cell) {
return (
<div className={cell.data.change > 0 ? 'inc' : 'dec' }>
<span>{cell.text}</span>
</div>
);
}
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.js';
ReactDOM.render(
<App />,
document.getElementById('app')
);
<!DOCTYPE html>
<html>
<head>
<title>DevExtreme Demo</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/21.1.6/css/dx.common.css" />
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/21.1.6/css/dx.light.css" />
<link rel="stylesheet" type="text/css" href="styles.css" />
<script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
<script src="https://unpkg.com/systemjs@0.21.3/dist/system.js"></script>
<script type="text/javascript" src="config.js"></script>
<script type="text/javascript">
System.import('./index.js');
</script>
</head>
<body class="dx-viewport">
<div class="demo-container">
<div id="app"></div>
</div>
</body>
</html>
#gridContainer span.current-value {
display: inline-block;
margin-right: 5px;
}
#gridContainer span.diff {
width: 50px;
display: inline-block;
}
#gridContainer .inc {
color: #2ab71b;
}
#gridContainer .dec {
color: #f00;
}
#gridContainer .inc .arrow,
#gridContainer .dec .arrow {
display: inline-block;
height: 10px;
width: 10px;
background-repeat: no-repeat;
background-size: 10px 10px;
}
#gridContainer .inc .arrow {
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAADKSURBVHjaYtTaLs1ABEiG0nPRJa56PEHhsxBhmCUQT4OyrwHxcXyKmQgYJgHE64CYDYrXQcXIMhCbAcgWkGzgNKh38QUB0QamIUUErkhKI9ZAGyCeTERkTYaqxWsgKA2txhdG6GGsvUNGGpeBRMUiGhCFGsqGzUBQQJsxkA5AemaiG5hDIBIIgQSgK0FmMDACs549kN5FZLjhA7+A2A2U9YSAOBeLAk4gnoBDczoOcSFGPIUDPxB/wCHHiKtwYGKgMhg1cBAaCBBgAJTUIL3ToPZfAAAAAElFTkSuQmCC');
}
#gridContainer .dec .arrow {
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAADJSURBVHjaYvzPgBfgkhYA4o8QFahKmBioDEYNHIQGsgBxIBCLkqgvAYi/g1mMjMjir0EJzR6If/6HpChKMMgMe3DKBeIcKhiY8x/MYoDj+RQYNgdkGLqBbEB8kgzDToL1YjEQhKWB+BUJhj0H64Eahs1AELYhMpJ+gtUiGYbLQBBOI8LANLBaIg1kAAc0vkiAqSPBQFAkHcNi2DGoHMkGgrAENOCRI0ECRQ2JBoKwJTQCfkLZDPgMZPxPXN5NhtJzMSsJVBMAAgwAyWSY2svfmrwAAAAASUVORK5CYII=');
}
window.config = {
transpiler: 'plugin-babel',
meta: {
'devextreme/localization.js': {
"esModule": true
},
},
paths: {
'npm:': 'https://unpkg.com/'
},
defaultExtension: 'js',
map: {
'react': 'npm:react@17.0.2/umd/react.development.js',
'react-dom': 'npm:react-dom@17.0.2/umd/react-dom.development.js',
'prop-types': 'npm:prop-types@15.7.2/prop-types.js',
'@aspnet/signalr': 'npm:@aspnet/signalr@1.0.0/dist/cjs',
'tslib': 'npm:tslib@2.3.1/tslib.js',
'rrule': 'npm:rrule@2.6.6/dist/es5/rrule.js',
'luxon': 'npm:luxon@1.28.0/build/global/luxon.min.js',
'es6-object-assign': 'npm:es6-object-assign@1.1.0',
'devextreme': 'npm:devextreme@21.1.6/cjs',
'devextreme-react': 'npm:devextreme-react@21.1.6',
'jszip': 'npm:jszip@3.7.1/dist/jszip.min.js',
'devextreme-quill': 'npm:devextreme-quill@1.4.2/dist/dx-quill.min.js',
'devexpress-diagram': 'npm:devexpress-diagram@2.1.32/dist/dx-diagram.js',
'devexpress-gantt': 'npm:devexpress-gantt@3.0.14/dist/dx-gantt.js',
'@devextreme/vdom': 'npm:@devextreme/vdom@1.2.2',
'inferno': 'npm:inferno@7.4.10/dist/inferno.min.js',
'inferno-compat': 'npm:inferno-compat@7.4.10/dist/inferno-compat.min.js',
'inferno-create-element': 'npm:inferno-create-element@7.4.10/dist/inferno-create-element.min.js',
'inferno-dom': 'npm:inferno-dom@1.0.7/dist/inferno-dom.min.js',
'inferno-hydrate': 'npm:inferno-hydrate@7.4.10/dist/inferno-hydrate.min.js',
'inferno-clone-vnode': 'npm:inferno-clone-vnode@7.4.10/dist/inferno-clone-vnode.min.js',
'inferno-create-class': 'npm:inferno-create-class@7.4.10/dist/inferno-create-class.min.js',
'inferno-extras': 'npm:inferno-extras@7.4.10/dist/inferno-extras.min.js',
// SystemJS plugins
'plugin-babel': 'npm:systemjs-plugin-babel@0.0.25/plugin-babel.js',
'systemjs-babel-build': 'npm:systemjs-plugin-babel@0.0.25/systemjs-babel-browser.js'
},
packages: {
'devextreme': {
defaultExtension: 'js'
},
'@devextreme/vdom': {
defaultExtension: 'js'
},
'devextreme-react': {
main: 'index.js'
},
'devextreme/events/utils': {
main: 'index'
},
'devextreme/events': {
main: 'index'
},
'@aspnet/signalr': {
main: 'index.js',
defaultExtension: 'js'
},
'es6-object-assign': {
main: './index.js',
defaultExtension: 'js'
}
},
packageConfigPaths: [
"npm:@devextreme/*/package.json",
],
babelOptions: {
sourceMaps: false,
stage0: true,
react: true
}
};
System.config(window.config);
using System.Collections.Generic;
using DevExtreme.MVC.Demos.Models.SignalR;
using Microsoft.AspNet.SignalR;
namespace DevExtreme.MVC.Demos.Hubs {
public class LiveUpdateSignalRHub : Hub {
private readonly StockTicker _stockTicker;
public LiveUpdateSignalRHub() {
_stockTicker = StockTicker.Instance;
}
public IEnumerable<Stock> GetAllStocks() {
return _stockTicker.GetAllStocks();
}
}
}
using System;
using System.Collections.Generic;
using System.Threading;
using DevExtreme.MVC.Demos.Hubs;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
namespace DevExtreme.MVC.Demos.Models.SignalR {
public class StockTicker {
public readonly static StockTicker Instance = new StockTicker(GlobalHost.ConnectionManager.GetHubContext<LiveUpdateSignalRHub>().Clients);
private readonly IEnumerable<Stock> _stocks;
private IHubConnectionContext<dynamic> Clients { get; set; }
private readonly TimeSpan _updateInterval = TimeSpan.FromMilliseconds(500);
private readonly Random _updateOrNotRandom = new Random();
private readonly Timer _timer;
private readonly object _updateStockPricesLock = new object();
static readonly Random random = new Random();
private StockTicker(IHubConnectionContext<dynamic> clients) {
Clients = clients;
_stocks = GenerateStocks();
_timer = new Timer(UpdateStockPrices, null, _updateInterval, _updateInterval);
}
public IEnumerable<Stock> GetAllStocks() {
return _stocks;
}
static IEnumerable<Stock> GenerateStocks() {
return new[] {
new Stock(37.95M) { Symbol = "MSFT", DayOpen=36.5M, LastUpdate = DateTime.Now },
new Stock(24.85M) { Symbol = "INTC", DayOpen=24.9M, LastUpdate = DateTime.Now },
new Stock(22.99M){ Symbol = "CSCO", DayOpen=22.7M, LastUpdate = DateTime.Now },
new Stock(30.71M){ Symbol = "SIRI", DayOpen=30.7M, LastUpdate = DateTime.Now },
new Stock(58.73M){ Symbol = "AAPL", DayOpen=54.9M, LastUpdate = DateTime.Now },
new Stock(110M){ Symbol = "HOKU", DayOpen=121.2M, LastUpdate = DateTime.Now },
new Stock(38.11M){ Symbol = "ORCL", DayOpen=37.9M, LastUpdate = DateTime.Now },
new Stock(17.61M) { Symbol = "AMAT", DayOpen=17.5M, LastUpdate = DateTime.Now },
new Stock(40.80M){ Symbol = "YHOO", DayOpen=39.9M, LastUpdate = DateTime.Now },
new Stock(31.85M){ Symbol = "LVLT", DayOpen=32.9M, LastUpdate = DateTime.Now },
new Stock(20.63M){ Symbol = "DELL", DayOpen=17.9M, LastUpdate = DateTime.Now },
new Stock(63.70M) { Symbol = "GOOG", DayOpen=55.9M, LastUpdate = DateTime.Now }
};
}
private void UpdateStockPrices(object state) {
lock(_updateStockPricesLock) {
foreach(var stock in _stocks) {
if(TryUpdateStockPrice(stock)) {
BroadcastStockPrice(stock);
}
}
}
}
private bool TryUpdateStockPrice(Stock stock) {
var r = _updateOrNotRandom.NextDouble();
if(r > .1) {
return false;
}
stock.Update();
return true;
}
private void BroadcastStockPrice(Stock stock) {
Clients.All.updateStockPrice(stock);
}
}
}
using System;
namespace DevExtreme.MVC.Demos.Models.SignalR {
public class Stock {
readonly decimal _initPrice;
public Stock(decimal price) {
Price = price;
DayMax = price;
DayMin = price;
_initPrice = Price;
}
public string Symbol { get; set; }
public decimal Price { get; set; }
public decimal DayMax { get; set; }
public decimal DayMin { get; set; }
public decimal DayOpen { get; set; }
public DateTime LastUpdate { get; set; }
public decimal Change {
get {
return Price - DayOpen;
}
}
public double PercentChange {
get {
return (double)Math.Round(Change * 100 / DayOpen, 2);
}
}
public void Update() {
var isNewDay = LastUpdate.Day != DateTime.Now.Day;
var change = GenerateChange();
var newPrice = _initPrice + _initPrice * change;
Price = newPrice;
LastUpdate = DateTime.Now;
if(Price > DayMax || isNewDay)
DayMax = Price;
if(Price < DayMin || isNewDay)
DayMin = Price;
}
static Random random = new Random();
decimal GenerateChange() {
return (decimal)random.Next(-200, 200) / 10000;
}
}
}