Backend API
import React, { useEffect, useState } from 'react';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import { CustomStore } from 'devextreme-react/common/data';
import DataGrid, { Column } from 'devextreme-react/data-grid';
import PriceCell from './PriceCell.tsx';
import ChangeCell from './ChangeCell.tsx';
const App = () => {
const [connectionStarted, setConnectionStarted] = useState(false);
const [dataSource, setDataSource] = useState<CustomStore | undefined>(undefined);
useEffect(() => {
const hubConnection = new HubConnectionBuilder()
.withUrl('https://js.devexpress.com/Demos/NetCore/liveUpdateSignalRHub', {
skipNegotiation: true,
transport: HttpTransportType.WebSockets,
})
.build();
const store = new CustomStore({
load: () => hubConnection.invoke('getAllStocks'),
key: 'symbol',
});
hubConnection
.start()
.then(() => {
hubConnection.on('updateStockPrice', (data) => {
store.push([{ type: 'update', key: data.symbol, data }]);
});
setConnectionStarted(true);
setDataSource(store);
});
}, []);
return (
<div>
{connectionStarted && (
<DataGrid
id="gridContainer"
dataSource={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, { useEffect, useState } from 'react';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import { CustomStore } from 'devextreme-react/common/data';
import DataGrid, { Column } from 'devextreme-react/data-grid';
import PriceCell from './PriceCell.js';
import ChangeCell from './ChangeCell.js';
const App = () => {
const [connectionStarted, setConnectionStarted] = useState(false);
const [dataSource, setDataSource] = useState(undefined);
useEffect(() => {
const hubConnection = new HubConnectionBuilder()
.withUrl('https://js.devexpress.com/Demos/NetCore/liveUpdateSignalRHub', {
skipNegotiation: true,
transport: HttpTransportType.WebSockets,
})
.build();
const store = new CustomStore({
load: () => hubConnection.invoke('getAllStocks'),
key: 'symbol',
});
hubConnection.start().then(() => {
hubConnection.on('updateStockPrice', (data) => {
store.push([{ type: 'update', key: data.symbol, data }]);
});
setConnectionStarted(true);
setDataSource(store);
});
}, []);
return (
<div>
{connectionStarted && (
<DataGrid
id="gridContainer"
dataSource={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 { type DataGridTypes } from 'devextreme-react/data-grid';
import React from 'react';
const ChangeCell = (cell: DataGridTypes.ColumnCellTemplateData) => (
<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>
);
export default ChangeCell;
import React from 'react';
import type { DataGridTypes } from 'devextreme-react/data-grid';
const PriceCell = (cell: DataGridTypes.ColumnCellTemplateData) => (
<div className={cell.data.change > 0 ? 'inc' : 'dec' }>
<span>{cell.text}</span>
</div>
);
export default PriceCell;
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.tsx';
ReactDOM.render(
<App />,
document.getElementById('app'),
);
import React from 'react';
const ChangeCell = (cell) => (
<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>
);
export default ChangeCell;
import React from 'react';
const PriceCell = (cell) => (
<div className={cell.data.change > 0 ? 'inc' : 'dec'}>
<span>{cell.text}</span>
</div>
);
export default PriceCell;
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.js';
ReactDOM.render(<App />, document.getElementById('app'));
<!DOCTYPE html>
<html lang="en">
<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=5.0" />
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/26.1.5/css/dx.light.css" />
<link rel="stylesheet" type="text/css" href="./bundle.css" />
</head>
<body class="dx-viewport">
<div class="demo-container">
<div id="app"></div>
</div>
<script src="bundles/vendor/react.vendor.js"></script>
<script src="./bundle.js"></script>
</body>
</html>
#gridContainer span.current-value {
display: inline-block;
margin-right: 5px;
}
#gridContainer span.diff {
width: 50px;
display: inline-block;
}
#gridContainer .inc {
color: var(--dx-color-success);
}
#gridContainer .dec {
color: var(--dx-color-danger);
}
#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=');
}
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;
using DevExpress.Data.Utils;
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 NonCryptographicRandom _updateOrNotRandom = NonCryptographicRandom.System;
private readonly Timer _timer;
private readonly object _updateStockPricesLock = new object();
static readonly NonCryptographicRandom random = NonCryptographicRandom.System;
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;
using DevExpress.Data.Utils;
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 NonCryptographicRandom random = NonCryptographicRandom.System;
decimal GenerateChange() {
return (decimal)random.Next(-200, 200) / 10000;
}
}
}
For more information about integration with push services, refer to the following help topic: Integration with Push Services.
Data used in this demo is for demonstration purposes only.