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.
$(() => {
$.connection.hub.url = 'https://js.devexpress.com/Demos/Mvc/signalr';
const hub = $.connection.liveUpdateSignalRHub;
const store = new DevExpress.data.CustomStore({
load() {
return hub.server.getAllStocks();
},
key: 'Symbol',
});
hub.client.updateStockPrice = function (data) {
store.push([{ type: 'update', key: data.Symbol, data }]);
};
$.connection.hub.start({ waitForPageLoad: false }).done(() => {
$('#gridContainer').dxDataGrid({
dataSource: store,
showBorders: true,
repaintChangesOnly: true,
highlightChanges: true,
columns: [{
dataField: 'LastUpdate',
dataType: 'date',
width: 115,
format: 'longTime',
}, {
dataField: 'Symbol',
}, {
dataField: 'Price',
dataType: 'number',
format: '#0.####',
cellTemplate(container, options) {
container.addClass((options.data.Change > 0) ? 'inc' : 'dec');
container.html(options.text);
},
}, {
dataField: 'Change',
dataType: 'number',
width: 140,
format: '#0.####',
cellTemplate(container, options) {
const fieldData = options.data;
container.addClass(fieldData.Change > 0 ? 'inc' : 'dec');
$('<span>')
.addClass('current-value')
.text(options.text)
.appendTo(container);
$('<span>')
.addClass('arrow')
.appendTo(container);
$('<span>')
.addClass('diff')
.text(`${fieldData.PercentChange.toFixed(2)}%`)
.appendTo(container);
},
}, {
dataField: 'DayOpen',
dataType: 'number',
format: '#0.####',
}, {
dataField: 'DayMin',
dataType: 'number',
format: '#0.####',
}, {
dataField: 'DayMax',
dataType: 'number',
format: '#0.####',
}],
});
});
});
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<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" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>window.jQuery || document.write(decodeURIComponent('%3Cscript src="js/jquery.min.js"%3E%3C/script%3E'))</script>
<script src="https://unpkg.com/signalr@2.4.3/jquery.signalR.js"></script>
<script src="../signalr-hub.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/22.2.6/css/dx.light.css" />
<script src="https://cdn3.devexpress.com/jslib/22.2.6/js/dx.all.js"></script>
<link rel="stylesheet" type="text/css" href="styles.css" />
<script src="index.js"></script>
</head>
<body class="dx-viewport">
<div class="demo-container">
<div id="gridContainer"></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=');
}
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;
}
}
}