Backend API
@if (connectionStarted) {
<div>
<dx-data-grid
id="gridContainer"
[dataSource]="dataSource"
[showBorders]="true"
[repaintChangesOnly]="true"
[highlightChanges]="true"
>
<dxi-data-grid-column
dataField="lastUpdate"
dataType="date"
[width]="115"
format="longTime"
>
</dxi-data-grid-column>
<dxi-data-grid-column dataField="symbol"> </dxi-data-grid-column>
<dxi-data-grid-column
dataField="price"
dataType="number"
format="#0.####"
cellTemplate="priceCellTemplate"
>
</dxi-data-grid-column>
<dxi-data-grid-column
dataField="change"
dataType="number"
[width]="140"
format="#0.####"
cellTemplate="changeCellTemplate"
>
</dxi-data-grid-column>
<dxi-data-grid-column
dataField="dayOpen"
dataType="number"
format="#0.####"
>
</dxi-data-grid-column>
<dxi-data-grid-column dataField="dayMin" dataType="number" format="#0.####">
</dxi-data-grid-column>
<dxi-data-grid-column dataField="dayMax" dataType="number" format="#0.####">
</dxi-data-grid-column>
<div
*dxTemplate="let cell of 'priceCellTemplate'"
[class.inc]="cell.data.change > 0"
[class.dec]="cell.data.change < 0"
>
<span>{{ cell.text }}</span>
</div>
<div
*dxTemplate="let cell of 'changeCellTemplate'"
[class.inc]="cell.data.change > 0"
[class.dec]="cell.data.change < 0"
>
<span class="current-value">{{ cell.text }}</span>
<span class="arrow"></span>
<span class="diff">{{ cell.data.percentChange.toFixed(2) }}%</span>
</div>
</dx-data-grid>
</div>
}
import { bootstrapApplication } from '@angular/platform-browser';
import {
ChangeDetectorRef, Component, enableProdMode, provideZoneChangeDetection,
} from '@angular/core';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import { DxDataGridModule } from 'devextreme-angular';
import { CustomStore } from 'devextreme-angular/common/data';
if (!/localhost/.test(document.location.host)) {
enableProdMode();
}
@Component({
selector: 'demo-app',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css'],
imports: [
DxDataGridModule,
],
})
export class AppComponent {
dataSource: CustomStore;
connectionStarted: boolean;
constructor(private changeDetectorRef: ChangeDetectorRef) {
this.connectionStarted = false;
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: Record<string, unknown>) => {
store.push([{ type: 'update', key: data.symbol, data }]);
});
this.dataSource = store;
this.connectionStarted = true;
this.changeDetectorRef.detectChanges();
});
}
}
bootstrapApplication(AppComponent, {
providers: [
provideZoneChangeDetection({ eventCoalescing: true, runCoalescing: true }),
],
});
::ng-deep #gridContainer span.current-value {
display: inline-block;
margin-right: 5px;
}
::ng-deep #gridContainer span.diff {
width: 50px;
display: inline-block;
}
::ng-deep #gridContainer .inc {
color: var(--dx-color-success);
}
::ng-deep #gridContainer .dec {
color: var(--dx-color-danger);
}
::ng-deep #gridContainer .inc .arrow,
::ng-deep #gridContainer .dec .arrow {
display: inline-block;
height: 10px;
width: 10px;
background-repeat: no-repeat;
background-size: 10px 10px;
}
::ng-deep #gridContainer .inc .arrow {
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAADKSURBVHjaYtTaLs1ABEiG0nPRJa56PEHhsxBhmCUQT4OyrwHxcXyKmQgYJgHE64CYDYrXQcXIMhCbAcgWkGzgNKh38QUB0QamIUUErkhKI9ZAGyCeTERkTYaqxWsgKA2txhdG6GGsvUNGGpeBRMUiGhCFGsqGzUBQQJsxkA5AemaiG5hDIBIIgQSgK0FmMDACs549kN5FZLjhA7+A2A2U9YSAOBeLAk4gnoBDczoOcSFGPIUDPxB/wCHHiKtwYGKgMhg1cBAaCBBgAJTUIL3ToPZfAAAAAElFTkSuQmCC');
}
::ng-deep #gridContainer .dec .arrow {
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAADJSURBVHjaYvzPgBfgkhYA4o8QFahKmBioDEYNHIQGsgBxIBCLkqgvAYi/g1mMjMjir0EJzR6If/6HpChKMMgMe3DKBeIcKhiY8x/MYoDj+RQYNgdkGLqBbEB8kgzDToL1YjEQhKWB+BUJhj0H64Eahs1AELYhMpJ+gtUiGYbLQBBOI8LANLBaIg1kAAc0vkiAqSPBQFAkHcNi2DGoHMkGgrAENOCRI0ECRQ2JBoKwJTQCfkLZDPgMZPxPXN5NhtJzMSsJVBMAAgwAyWSY2svfmrwAAAAASUVORK5CYII=');
}
<!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" />
</head>
<body class="dx-viewport">
<div class="demo-container">
<demo-app>Loading...</demo-app>
</div>
<script src="https://cdn.jsdelivr.net/npm/zone.js@0.16.2/bundles/zone.umd.js"></script>
<script src="./bundle.js" type="module"></script>
</body>
</html>
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.