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.

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Backend API

<template> <div v-if="connectionStarted"> <DxDataGrid id="gridContainer" :data-source="dataSource" :repaint-changes-only="true" :highlight-changes="true" :show-borders="true" > <DxColumn :width="115" data-field="lastUpdate" data-type="date" format="longTime" /> <DxColumn data-field="symbol" /> <DxColumn data-field="price" data-type="number" format="#0.####" cell-template="priceCellTemplate" /> <DxColumn :width="140" data-field="change" data-type="number" format="#0.####" cell-template="changeCellTemplate" /> <DxColumn data-field="dayOpen" data-type="number" format="#0.####" /> <DxColumn data-field="dayMin" data-type="number" format="#0.####" /> <DxColumn data-field="dayMax" data-type="number" format="#0.####" /> <template #priceCellTemplate="{ data: cellData }"> <PriceCell :cell-data="cellData"/> </template> <template #changeCellTemplate="{ data: cellData }"> <ChangeCell :cell-data="cellData"/> </template> </DxDataGrid> </div> </template> <script setup lang="ts"> import { onMounted, ref } from 'vue'; import { DxDataGrid, DxColumn, } from 'devextreme-vue/data-grid'; import CustomStore from 'devextreme/data/custom_store'; import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr'; import PriceCell from './PriceCell.vue'; import ChangeCell from './ChangeCell.vue'; const connectionStarted = ref(false); const dataSource = ref<CustomStore | null>(null); onMounted(() => { 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 }]); }); dataSource.value = store; connectionStarted.value = true; }); }); </script> <style> #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='); } </style>

<template> <div :class="{ inc: cellData.data.change > 0, dec: cellData.data.change < 0 }"> <span class="current-value">{{ cellData.text }}</span> <span class="arrow"/> <span class="diff">{{ cellData.data.percentChange.toFixed(2) }}%</span> </div> </template> <script setup lang="ts"> import { ColumnCellTemplateData } from 'devextreme/ui/data_grid'; defineProps<{ cellData: ColumnCellTemplateData }>(); </script>

<template> <div :class="{ inc: cellData.data.change > 0, dec: cellData.data.change < 0 }"> <span>{{ cellData.text }}</span> </div> </template> <script setup lang="ts"> import { ColumnCellTemplateData } from 'devextreme/ui/data_grid'; defineProps<{ cellData: ColumnCellTemplateData }>(); </script>

import { createApp } from 'vue'; import App from './App.vue'; createApp(App).mount('#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/23.1.5/css/dx.light.css" /> <script type="module"> import * as vueCompilerSFC from "https://unpkg.com/@vue/compiler-sfc@3.3.4/dist/compiler-sfc.esm-browser.js"; window.vueCompilerSFC = vueCompilerSFC; </script> <script src="https://unpkg.com/typescript@3.9.10/lib/typescript.js"></script> <script src="https://unpkg.com/core-js@2.6.12/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>

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; } } }