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Backend API
import React, {
useCallback, useEffect, useRef, useState,
} from 'react';
import Chart, {
ArgumentAxis,
ValueAxis,
Aggregation,
Legend,
Series,
ScrollBar,
ZoomAndPan,
LoadingIndicator,
Pane,
Tooltip,
Crosshair,
Margin,
HorizontalLine,
IAggregationProps,
} from 'devextreme-react/chart';
import { VisualRange } from 'devextreme-react/common/charts';
import CustomStore from 'devextreme/data/custom_store';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import TooltipTemplate from './TooltipTemplate.tsx';
const minVisualRangeLength = { minutes: 10 };
const defaultVisualRange: VisualRange = { length: 'hour' };
function App() {
const [dataSource, setDataSource] = useState(null);
const chartRef = useRef(null);
const customizePoint = useCallback((arg) => {
if (arg.seriesName === 'Volume') {
const point = chartRef.current.instance().getAllSeries()[0]
.getPointsByArg(arg.argument)[0].data;
if (point && point.close >= point.open) {
return { color: '#1db2f5' };
}
}
return null;
}, []);
const calculateCandle = useCallback<IAggregationProps['calculate']>((e) => {
const prices = e.data.map((d) => d.price);
if (prices.length) {
return {
date: new Date((e.intervalStart.valueOf() + e.intervalEnd.valueOf()) / 2),
open: prices[0],
high: Math.max.apply(null, prices),
low: Math.min.apply(null, prices),
close: prices[prices.length - 1],
};
}
return null;
}, []);
useEffect(() => {
const hubConnection = new HubConnectionBuilder()
.withUrl('https://js.devexpress.com/Demos/NetCore/stockTickDataHub', {
skipNegotiation: true,
transport: HttpTransportType.WebSockets,
})
.build();
const store = new CustomStore({
load: () => hubConnection.invoke('getAllData'),
key: 'date',
});
hubConnection
.start()
.then(() => {
hubConnection.on('updateStockPrice', (data) => {
store.push([{ type: 'insert', key: data.date, data }]);
});
setDataSource(store);
});
}, []);
return (
<div>
<Chart
id="chart"
ref={chartRef}
dataSource={dataSource}
title="Stock Price"
customizePoint={customizePoint}>
<Margin right={30} />
<Series
pane="Price"
argumentField="date"
type="candlestick">
<Aggregation
enabled={true}
method="custom"
calculate={calculateCandle} />
</Series>
<Series
pane="Volume"
name="Volume"
argumentField="date"
valueField="volume"
color="red"
type="bar">
<Aggregation
enabled={true}
method="sum" />
</Series>
<Pane name="Price"></Pane>
<Pane name="Volume" height={80}></Pane>
<Legend visible={false} />
<ArgumentAxis
argumentType="datetime"
minVisualRangeLength={minVisualRangeLength}
defaultVisualRange={defaultVisualRange} />
<ValueAxis placeholderSize={50} />
<ZoomAndPan argumentAxis="both" />
<ScrollBar visible={true} />
<LoadingIndicator enabled={true} />
<Tooltip
enabled={true}
shared={true}
argumentFormat="shortDateShortTime"
contentRender={TooltipTemplate}
/>
<Crosshair
enabled={true}>
<HorizontalLine visible={false} />
</Crosshair>
</Chart>
</div>
);
}
export default App;
import React, {
useCallback, useEffect, useRef, useState,
} from 'react';
import Chart, {
ArgumentAxis,
ValueAxis,
Aggregation,
Legend,
Series,
ScrollBar,
ZoomAndPan,
LoadingIndicator,
Pane,
Tooltip,
Crosshair,
Margin,
HorizontalLine,
} from 'devextreme-react/chart';
import CustomStore from 'devextreme/data/custom_store';
import { HubConnectionBuilder, HttpTransportType } from '@aspnet/signalr';
import TooltipTemplate from './TooltipTemplate.js';
const minVisualRangeLength = { minutes: 10 };
const defaultVisualRange = { length: 'hour' };
function App() {
const [dataSource, setDataSource] = useState(null);
const chartRef = useRef(null);
const customizePoint = useCallback((arg) => {
if (arg.seriesName === 'Volume') {
const point = chartRef.current
.instance()
.getAllSeries()[0]
.getPointsByArg(arg.argument)[0].data;
if (point && point.close >= point.open) {
return { color: '#1db2f5' };
}
}
return null;
}, []);
const calculateCandle = useCallback((e) => {
const prices = e.data.map((d) => d.price);
if (prices.length) {
return {
date: new Date((e.intervalStart.valueOf() + e.intervalEnd.valueOf()) / 2),
open: prices[0],
high: Math.max.apply(null, prices),
low: Math.min.apply(null, prices),
close: prices[prices.length - 1],
};
}
return null;
}, []);
useEffect(() => {
const hubConnection = new HubConnectionBuilder()
.withUrl('https://js.devexpress.com/Demos/NetCore/stockTickDataHub', {
skipNegotiation: true,
transport: HttpTransportType.WebSockets,
})
.build();
const store = new CustomStore({
load: () => hubConnection.invoke('getAllData'),
key: 'date',
});
hubConnection.start().then(() => {
hubConnection.on('updateStockPrice', (data) => {
store.push([{ type: 'insert', key: data.date, data }]);
});
setDataSource(store);
});
}, []);
return (
<div>
<Chart
id="chart"
ref={chartRef}
dataSource={dataSource}
title="Stock Price"
customizePoint={customizePoint}
>
<Margin right={30} />
<Series
pane="Price"
argumentField="date"
type="candlestick"
>
<Aggregation
enabled={true}
method="custom"
calculate={calculateCandle}
/>
</Series>
<Series
pane="Volume"
name="Volume"
argumentField="date"
valueField="volume"
color="red"
type="bar"
>
<Aggregation
enabled={true}
method="sum"
/>
</Series>
<Pane name="Price"></Pane>
<Pane
name="Volume"
height={80}
></Pane>
<Legend visible={false} />
<ArgumentAxis
argumentType="datetime"
minVisualRangeLength={minVisualRangeLength}
defaultVisualRange={defaultVisualRange}
/>
<ValueAxis placeholderSize={50} />
<ZoomAndPan argumentAxis="both" />
<ScrollBar visible={true} />
<LoadingIndicator enabled={true} />
<Tooltip
enabled={true}
shared={true}
argumentFormat="shortDateShortTime"
contentRender={TooltipTemplate}
/>
<Crosshair enabled={true}>
<HorizontalLine visible={false} />
</Crosshair>
</Chart>
</div>
);
}
export default App;
import React from 'react';
const formatCurrency = new Intl.NumberFormat('en-US',
{ style: 'currency', currency: 'USD', minimumFractionDigits: 0 }).format;
const formatNumber = new Intl.NumberFormat('en-US', {
minimumFractionDigits: 0,
}).format;
export default function TooltipTemplate(pointInfo) {
const volume = pointInfo.points.filter((point: { seriesName: string; }) => point.seriesName === 'Volume')[0];
const prices = pointInfo.points.filter((point: { seriesName: string; }) => point.seriesName !== 'Volume')[0];
return (
<div className="tooltip-template">
<div>{ pointInfo.argumentText }</div>
<div><span>Open: </span>
{ formatCurrency(prices.openValue) }
</div>
<div><span>High: </span>
{ formatCurrency(prices.highValue) }
</div>
<div><span>Low: </span>
{ formatCurrency(prices.lowValue) }
</div>
<div><span>Close: </span>
{ formatCurrency(prices.closeValue) }
</div>
<div><span>Volume: </span>
{ formatNumber(volume.value) }
</div>
</div>
);
}
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.tsx';
ReactDOM.render(
<App />,
document.getElementById('app'),
);
window.exports = window.exports || {};
window.config = {
transpiler: 'ts',
typescriptOptions: {
module: 'system',
emitDecoratorMetadata: true,
experimentalDecorators: true,
jsx: 'react',
},
meta: {
'react': {
'esModule': true,
},
'typescript': {
'exports': 'ts',
},
'devextreme/time_zone_utils.js': {
'esModule': true,
},
'devextreme/localization.js': {
'esModule': true,
},
'devextreme/viz/palette.js': {
'esModule': true,
},
},
paths: {
'npm:': 'https://unpkg.com/',
},
defaultExtension: 'js',
map: {
'ts': 'npm:plugin-typescript@4.2.4/lib/plugin.js',
'typescript': 'npm:typescript@4.2.4/lib/typescript.js',
'react': 'npm:react@17.0.2/umd/react.development.js',
'react-dom': 'npm:react-dom@17.0.2/umd/react-dom.development.js',
'prop-types': 'npm:prop-types@15.8.1/prop-types.js',
'@aspnet/signalr': 'npm:@aspnet/signalr@1.0.27/dist/cjs',
'tslib': 'npm:tslib@2.6.1/tslib.js',
'rrule': 'npm:rrule@2.6.4/dist/es5/rrule.js',
'luxon': 'npm:luxon@1.28.1/build/global/luxon.min.js',
'es6-object-assign': 'npm:es6-object-assign@1.1.0',
'devextreme': 'npm:devextreme@24.1.7/cjs',
'devextreme-react': 'npm:devextreme-react@24.1.7/cjs',
'jszip': 'npm:jszip@3.10.1/dist/jszip.min.js',
'devextreme-quill': 'npm:devextreme-quill@1.7.1/dist/dx-quill.min.js',
'devexpress-diagram': 'npm:devexpress-diagram@2.2.12/dist/dx-diagram.js',
'devexpress-gantt': 'npm:devexpress-gantt@4.1.56/dist/dx-gantt.js',
'@devextreme/runtime': 'npm:@devextreme/runtime@3.0.13',
'inferno': 'npm:inferno@7.4.11/dist/inferno.min.js',
'inferno-compat': 'npm:inferno-compat/dist/inferno-compat.min.js',
'inferno-create-element': 'npm:inferno-create-element@7.4.11/dist/inferno-create-element.min.js',
'inferno-dom': 'npm:inferno-dom/dist/inferno-dom.min.js',
'inferno-hydrate': 'npm:inferno-hydrate@7.4.11/dist/inferno-hydrate.min.js',
'inferno-clone-vnode': 'npm:inferno-clone-vnode/dist/inferno-clone-vnode.min.js',
'inferno-create-class': 'npm:inferno-create-class/dist/inferno-create-class.min.js',
'inferno-extras': 'npm:inferno-extras/dist/inferno-extras.min.js',
'devextreme-cldr-data': 'npm:devextreme-cldr-data@1.0.3',
// SystemJS plugins
'plugin-babel': 'npm:systemjs-plugin-babel@0.0.25/plugin-babel.js',
'systemjs-babel-build': 'npm:systemjs-plugin-babel@0.0.25/systemjs-babel-browser.js',
// Prettier
'prettier/standalone': 'npm:prettier@2.8.8/standalone.js',
'prettier/parser-html': 'npm:prettier@2.8.8/parser-html.js',
},
packages: {
'devextreme': {
defaultExtension: 'js',
},
'devextreme-react': {
main: 'index.js',
},
'devextreme/events/utils': {
main: 'index',
},
'devextreme/localization/messages': {
format: 'json',
defaultExtension: 'json',
},
'devextreme/events': {
main: 'index',
},
'@aspnet/signalr': {
main: 'index.js',
defaultExtension: 'js',
},
'es6-object-assign': {
main: './index.js',
defaultExtension: 'js',
},
},
packageConfigPaths: [
'npm:@devextreme/*/package.json',
'npm:@devextreme/runtime@3.0.13/inferno/package.json',
],
babelOptions: {
sourceMaps: false,
stage0: true,
react: true,
},
};
System.config(window.config);
import React from 'react';
const formatCurrency = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
}).format;
const formatNumber = new Intl.NumberFormat('en-US', {
minimumFractionDigits: 0,
}).format;
export default function TooltipTemplate(pointInfo) {
const volume = pointInfo.points.filter((point) => point.seriesName === 'Volume')[0];
const prices = pointInfo.points.filter((point) => point.seriesName !== 'Volume')[0];
return (
<div className="tooltip-template">
<div>{pointInfo.argumentText}</div>
<div>
<span>Open: </span>
{formatCurrency(prices.openValue)}
</div>
<div>
<span>High: </span>
{formatCurrency(prices.highValue)}
</div>
<div>
<span>Low: </span>
{formatCurrency(prices.lowValue)}
</div>
<div>
<span>Close: </span>
{formatCurrency(prices.closeValue)}
</div>
<div>
<span>Volume: </span>
{formatNumber(volume.value)}
</div>
</div>
);
}
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/24.1.7/css/dx.light.css" />
<link rel="stylesheet" type="text/css" href="styles.css" />
<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.tsx");
</script>
</head>
<body class="dx-viewport">
<div class="demo-container">
<div id="app"></div>
</div>
</body>
</html>
#chart {
height: 440px;
}
.tooltip-template span {
font-weight: 500;
}
using System.Collections.Generic;
using DevExtreme.MVC.Demos.Models.SignalRTickData;
using Microsoft.AspNet.SignalR;
namespace DevExtreme.MVC.Demos.Hubs {
public class StockTickDataHub : Hub {
private readonly TickDataService _service;
public StockTickDataHub() {
_service = TickDataService.Instance;
}
public IEnumerable<TickItem> GetAllData() {
return _service.GetAllData();
}
}
}
using DevExtreme.MVC.Demos.Hubs;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using System;
using System.Collections.Generic;
using System.Threading;
using DevExpress.Data.Utils;
namespace DevExtreme.MVC.Demos.Models.SignalRTickData {
public class TickDataService {
public readonly static TickDataService Instance = new TickDataService(GlobalHost.ConnectionManager.GetHubContext<StockTickDataHub>().Clients);
private IHubConnectionContext<dynamic> Clients { get; set; }
private readonly object updateStockPricesLock = new object();
private TickItem[] tickData;
private int lastTickIndex;
private Timer timer;
private TickDataService(IHubConnectionContext<dynamic> clients) {
Clients = clients;
tickData = GenerateTestData();
lastTickIndex = tickData.Length - 1;
timer = new Timer(Update, null, 1000, 1000);
}
public IEnumerable<TickItem> GetAllData() {
var data = new List<TickItem>();
lock(updateStockPricesLock) {
for(var i = lastTickIndex; data.Count < 10000; i--) {
data.Add(tickData[i]);
if(i == 0) {
i = tickData.Length - 1;
}
}
}
return data;
}
private void Update(object state) {
lock(updateStockPricesLock) {
lastTickIndex = (lastTickIndex + 1) % tickData.Length;
var tick = tickData[lastTickIndex];
tick.Date = DateTime.Now;
BroadcastStockPrice(tick);
}
}
private void BroadcastStockPrice(TickItem item) {
Clients.All.updateStockPrice(item);
}
private TickItem[] GenerateTestData() {
var lastPrice = 140m;
var random = NonCryptographicRandom.System;
var slowRandomValue = random.NextDouble();
var data = new TickItem[60 * 60 * 20];
var curTime = DateTime.Now;
for(var i = 0; i < data.Length / 2; i++) {
lastPrice = Math.Round(lastPrice * (decimal)(1 + 0.002 * (-1 + 2 * random.NextDouble())), 2);
if(i % 50 == 0) {
slowRandomValue = random.NextDouble();
if(slowRandomValue > 0.3 && slowRandomValue <= 0.5) slowRandomValue -= 0.2;
if(slowRandomValue > 0.5 && slowRandomValue <= 0.7) slowRandomValue += 0.2;
}
var volume = (int)(100 + 1900 * random.NextDouble() * slowRandomValue);
data[data.Length - 1 - i] = new TickItem(lastPrice, volume, curTime.AddSeconds(-1 * i));
data[i] = new TickItem(lastPrice, volume, curTime.AddSeconds(-1 * (data.Length - 1 - i)));
}
return data;
}
}
}
To display updated data in real time, use the aggregation configuration object. In this object, set the enabled property to true, the method property to custom
, and then implement the calculate function to process the incoming data. In this demo, the calculate function aggregates data into a one point for each interval.
You can also use the contentTemplate function to update the tooltip content with incoming data.