Client-Side Data Processing

import React from 'react'; import DataSource from 'devextreme/data/data_source'; import CustomStore from 'devextreme/data/custom_store'; import Chart, { ValueAxis, Label, Legend, Series, Size, Export, LoadingIndicator } from 'devextreme-react/chart'; import SelectBox from 'devextreme-react/select-box'; class App extends React.Component { constructor(props) { super(props); this.temperature = [6, 7, 8, 9, 10, 11, 12]; this.palette = ['#c3a2cc', '#b7b5e0', '#e48cba']; this.paletteIndex = 0; this.monthWeather = new DataSource({ store: new CustomStore({ load: () => { return fetch('../../../../data/monthWeather.json') .then(e => e.json()) .catch(() => { throw 'Data Loading Error'; }); }, loadMode: 'raw' }), filter: ['t', '>', '6'], paginate: false }); this.customizePoint = () => { const color = this.palette[this.paletteIndex]; this.paletteIndex = this.paletteIndex === 2 ? 0 : this.paletteIndex + 1; return { color }; }; this.changeTemperature = (e) => { this.monthWeather.filter(['t', '>', e.value]); this.monthWeather.load(); }; } customizeLabel(e) { return `${e.valueText}${'&#176C'}`; } render() { return ( <div id={'chart-demo'}> <Chart title={'Temperature in Barcelona: January 2012'} dataSource={this.monthWeather} customizePoint={this.customizePoint}> <Size height={420} /> <ValueAxis> <Label customizeText={this.customizeLabel} /> </ValueAxis> <Series argumentField={'day'} valueField={'t'} type={'bar'} /> <Legend visible={false} /> <Export enabled={true} /> <LoadingIndicator enabled={true} /> </Chart> <div className={'action'}> <SelectBox id={'choose-temperature'} dataSource={this.temperature} width={70} defaultValue={6} onValueChanged={this.changeTemperature} /> <div className={'label'}>Choose a temperature threshold, &deg;C: </div> </div> </div> ); } } export default App;