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.
@using DevExtreme.MVC.Demos.Models.SignalR
@(Html.DevExtreme().DataGrid<Stock>()
.ID("gridContainer")
.LoadPanel(loadPanel => loadPanel.Enabled(false))
.OnInitialized("onInitialized")
.RepaintChangesOnly(true)
.HighlightChanges(true)
.ShowBorders(true)
.Columns(columns => {
columns.AddFor(m => m.LastUpdate)
.Width(115)
.Format(Format.LongTime);
columns.AddFor(m => m.Symbol);
columns.AddFor(m => m.Price)
.Format("#0.####")
.CellTemplate(@<text>
<span class="<%- data.Change > 0 ? 'inc' : 'dec' %>">
<%- text %>
</span>
</text>);
columns.AddFor(m => m.Change)
.Width(140)
.Format("#0.####")
.CellTemplate(@<text>
<span class="<%- data.Change > 0 ? 'inc' : 'dec' %>">
<span class="current-value"><%- text %></span>
<span class="arrow"></span>
<span class="diff"><%- data.PercentChange.toFixed(2) %>%</span>
</span>
</text>);
columns.AddFor(m => m.DayOpen)
.Format("#0.####");
columns.AddFor(m => m.DayMin)
.Format("#0.####");
columns.AddFor(m => m.DayMax)
.Format("#0.####");
})
)
<script src="~/Scripts/jquery.signalR-2.2.2.js"></script>
<script src="~/signalr/hubs"></script>
<script>
function onInitialized(e) {
e.component.beginCustomLoading();
}
$(function () {
var hub = $.connection.liveUpdateSignalRHub;
var store = new DevExpress.data.CustomStore({
load: function () {
return hub.server.getAllStocks();
},
key: "Symbol"
});
hub.client.updateStockPrice = function (data) {
store.push([{ type: "update", key: data.Symbol, data: data }]);
};
$.connection.hub.start({ waitForPageLoad: false }).done(function () {
$("#gridContainer").dxDataGrid({
dataSource: store
});
});
});
</script>
using DevExtreme.MVC.Demos.Models;
using DevExtreme.MVC.Demos.Models.DataGrid;
using DevExtreme.MVC.Demos.Models.SampleData;
using System;
using System.Linq;
using System.Web.Mvc;
namespace DevExtreme.MVC.Demos.Controllers {
public class DataGridController : Controller {
public ActionResult SignalRService() {
return View();
}
}
}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 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;
}
}
}
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);
}
}
}
#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=');
}