Customize Drop-Down Button

import React from 'react'; import SelectBox from 'devextreme-react/select-box'; import { Template } from 'devextreme-react/core/template'; import { products, simpleProducts } from './data.js'; import ImageIcon from './imageIcon.js'; import IndicatorIcon from './indicatorIcon.js'; import ConditionalIcon from './conditionalIcon.js'; import Item from './item.js'; class App extends React.Component { constructor(props) { super(props); this.deferredProducts = { loadMode: 'raw', load: () => { this.setState({ isLoaded: false }); const promise = new Promise((resolve) => { setTimeout(() => { resolve(simpleProducts); this.setState({ isLoaded: true }); }, 3000); }); return promise; }, }; this.state = { selectedItem: products[0], isLoaded: true, }; this.renderLoadIndicator = this.renderLoadIndicator.bind(this); this.renderConditionalIcon = this.renderConditionalIcon.bind(this); this.selectionChanged = this.selectionChanged.bind(this); } render() { return ( <div className='dx-fieldset'> <div className='dx-field'> <div className='dx-field-label'>Image as the icon</div> <div className='dx-field-value'> <SelectBox dataSource={simpleProducts} dropDownButtonRender={ImageIcon} /> </div> </div> <div className='dx-field'> <div className='dx-field-label'>Load indicator as the icon</div> <div className='dx-field-value'> <SelectBox dataSource={this.deferredProducts} dropDownButtonTemplate='loadIndicator'> <Template name='loadIndicator' render={this.renderLoadIndicator} /> </SelectBox> </div> </div> <div className='dx-field'> <div className='dx-field-label'>Value-dependent icon</div> <div className='dx-field-value'> <SelectBox dataSource={products} defaultValue={products[0].ID} selectedItem={this.state.selectedItem} displayExpr='Name' showClearButton={true} valueExpr='ID' itemRender={Item} dropDownButtonTemplate='conditionalIcon' onSelectionChanged={this.selectionChanged} > <Template name='conditionalIcon' render={this.renderConditionalIcon} /> </SelectBox> </div> </div> </div> ); } renderLoadIndicator() { return <IndicatorIcon isLoaded={this.state.isLoaded} />; } renderConditionalIcon() { return <ConditionalIcon value={this.state.selectedItem} />; } selectionChanged({ selectedItem }) { this.setState({ selectedItem }); } } export default App;