React Charts - Server-Side Data Processing

DevExtreme Chart supports remote data processing. In this demo, the component loads weather data for a specified month from an ASP.NET backend service. When you change a month in the drop down, the Chart component sends a new query to update displayed data.

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TS JS

Backend API

import React from 'react'; import { DataSource } from 'devextreme-react/common/data'; import Chart, { ValueAxis, ArgumentAxis, CommonPaneSettings, Grid, Series, Label, Legend, Size, Border, Tooltip, Export, LoadingIndicator, } from 'devextreme-react/chart'; import type { ChartTypes } from 'devextreme-react/chart'; import SelectBox from 'devextreme-react/select-box'; import type { SelectBoxTypes } from 'devextreme-react/select-box'; import { months, monthLabel } from './data.ts'; const year = 2017; let selectedMonth = 1; const startOfMonthStr = (month: number): string => `${month}/01/${year}`; const endOfMonthStr = (month: number): string => { const nextMonth = (month === 12) ? 1 : month + 1; const nextYear = (month === 12) ? year + 1 : year; const lastDay = new Date(nextYear, nextMonth - 1, 0).getDate(); return `${month}/${lastDay}/${year}`; }; const chartDataSource = new DataSource({ key: 'Date', load: () => { const startVisible = startOfMonthStr(selectedMonth); const endVisible = endOfMonthStr(selectedMonth); const url = 'https://js.devexpress.com/Demos/NetCore/api/TemperatureData' + `?startVisible=${encodeURIComponent(startVisible)}` + `&endVisible=${encodeURIComponent(endVisible)}` + `&startBound=${encodeURIComponent(startVisible)}` + `&endBound=${encodeURIComponent(endVisible)}`; return fetch(url) .then((r) => { if (!r.ok) throw new Error(`Network response fails: ${r.status}`); return r.json(); }) .then((arr) => arr.map((item: { MinTemp: number, MaxTemp: number, Date: string }) => ({ ...item, Temperature: (item.MinTemp + item.MaxTemp) / 2, Date: new Date(item.Date), }))); }, paginate: false, }); function onValueChanged(data: SelectBoxTypes.ValueChangedEvent): void { selectedMonth = data.value; chartDataSource.load(); } function customizeLabel(e: { valueText: string; }): string { return `${e.valueText}${'&#176C'}`; } function customizeArgumentAxisLabel(e: { value: string | number | Date, valueText: string; }): string { return new Date(e.value).getDate().toString(); } function customizeTooltip({ valueText }: ChartTypes.PointInfo): Record<string, string> { return { text: `${valueText}${'&#176C'}`, }; } function App() { return ( <div id="chart-demo"> <Chart title={`Temperature in Seattle, ${year}`} dataSource={chartDataSource}> <Size height={420} /> <ValueAxis valueType="numeric"> <Grid opacity={0.2} /> <Label customizeText={customizeLabel} /> </ValueAxis> <ArgumentAxis type="discrete"> <Grid visible={true} opacity={0.5} /> <Label customizeText={customizeArgumentAxisLabel} /> </ArgumentAxis> <CommonPaneSettings> <Border visible={true} width={2} top={false} right={false} /> </CommonPaneSettings> <Series argumentField="Date" valueField="Temperature" type="spline" /> <Legend visible={false} /> <Export enabled={true} /> <Tooltip enabled={true} customizeTooltip={customizeTooltip} /> <LoadingIndicator enabled={true} /> </Chart> <div className="action"> <div className="label">Choose a month:</div> <SelectBox id="selectbox" width={150} valueExpr="id" inputAttr={monthLabel} displayExpr="name" items={months} defaultValue={selectedMonth} onValueChanged={onValueChanged} /> </div> </div> ); } export default App;

import React from 'react'; import { DataSource } from 'devextreme-react/common/data'; import Chart, { ValueAxis, ArgumentAxis, CommonPaneSettings, Grid, Series, Label, Legend, Size, Border, Tooltip, Export, LoadingIndicator, } from 'devextreme-react/chart'; import SelectBox from 'devextreme-react/select-box'; import { months, monthLabel } from './data.js'; const year = 2017; let selectedMonth = 1; const startOfMonthStr = (month) => `${month}/01/${year}`; const endOfMonthStr = (month) => { const nextMonth = month === 12 ? 1 : month + 1; const nextYear = month === 12 ? year + 1 : year; const lastDay = new Date(nextYear, nextMonth - 1, 0).getDate(); return `${month}/${lastDay}/${year}`; }; const chartDataSource = new DataSource({ key: 'Date', load: () => { const startVisible = startOfMonthStr(selectedMonth); const endVisible = endOfMonthStr(selectedMonth); const url = 'https://js.devexpress.com/Demos/NetCore/api/TemperatureData' + `?startVisible=${encodeURIComponent(startVisible)}` + `&endVisible=${encodeURIComponent(endVisible)}` + `&startBound=${encodeURIComponent(startVisible)}` + `&endBound=${encodeURIComponent(endVisible)}`; return fetch(url) .then((r) => { if (!r.ok) throw new Error(`Network response fails: ${r.status}`); return r.json(); }) .then((arr) => arr.map((item) => ({ ...item, Temperature: (item.MinTemp + item.MaxTemp) / 2, Date: new Date(item.Date), })), ); }, paginate: false, }); function onValueChanged(data) { selectedMonth = data.value; chartDataSource.load(); } function customizeLabel(e) { return `${e.valueText}${'&#176C'}`; } function customizeArgumentAxisLabel(e) { return new Date(e.value).getDate().toString(); } function customizeTooltip({ valueText }) { return { text: `${valueText}${'&#176C'}`, }; } function App() { return ( <div id="chart-demo"> <Chart title={`Temperature in Seattle, ${year}`} dataSource={chartDataSource} > <Size height={420} /> <ValueAxis valueType="numeric"> <Grid opacity={0.2} /> <Label customizeText={customizeLabel} /> </ValueAxis> <ArgumentAxis type="discrete"> <Grid visible={true} opacity={0.5} /> <Label customizeText={customizeArgumentAxisLabel} /> </ArgumentAxis> <CommonPaneSettings> <Border visible={true} width={2} top={false} right={false} /> </CommonPaneSettings> <Series argumentField="Date" valueField="Temperature" type="spline" /> <Legend visible={false} /> <Export enabled={true} /> <Tooltip enabled={true} customizeTooltip={customizeTooltip} /> <LoadingIndicator enabled={true} /> </Chart> <div className="action"> <div className="label">Choose a month:</div> <SelectBox id="selectbox" width={150} valueExpr="id" inputAttr={monthLabel} displayExpr="name" items={months} defaultValue={selectedMonth} onValueChanged={onValueChanged} /> </div> </div> ); } export default App;

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.tsx'; ReactDOM.render( <App />, document.getElementById('app'), );

export const months = [{ id: 1, name: 'January', }, { id: 2, name: 'February', }, { id: 3, name: 'March', }, { id: 4, name: 'April', }, { id: 5, name: 'May', }, { id: 6, name: 'June', }, { id: 7, name: 'July', }, { id: 8, name: 'August', }, { id: 9, name: 'September', }, { id: 10, name: 'October', }, { id: 11, name: 'November', }, { id: 12, name: 'December', }]; export const monthLabel = { 'aria-label': 'Month' };

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.js'; ReactDOM.render(<App />, document.getElementById('app'));

export const months = [ { id: 1, name: 'January', }, { id: 2, name: 'February', }, { id: 3, name: 'March', }, { id: 4, name: 'April', }, { id: 5, name: 'May', }, { id: 6, name: 'June', }, { id: 7, name: 'July', }, { id: 8, name: 'August', }, { id: 9, name: 'September', }, { id: 10, name: 'October', }, { id: 11, name: 'November', }, { id: 12, name: 'December', }, ]; export const monthLabel = { 'aria-label': 'Month' };

<!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/25.2.4/css/dx.light.css" /> <link rel="stylesheet" type="text/css" href="styles.css" /> <script src="https://cdn.jsdelivr.net/npm/core-js@2.6.12/client/shim.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/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>

.action { width: 270px; margin-top: 20px; display: flex; justify-content: space-between; align-items: center; }

To bind data from a remote source, the demo implements a CustomStore (within a DataSource object) and fetches data using the load method. To process data on the server, the ASP.NET backend service is configured to accept processing operations in each request. For backend implementation details, refer to TemperatureDataController.cs in the ASP.NET Core version of this demo: Server-Side Data Processing - ASP.NET Core Charts.

You can shape data within the DataSource as needed (for instance, apply a filter). Disable the paginate property to prevent data partitioning.

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