ComboBox with Infinite Scrolling (React)

The ComboBox below populates the drop-down list by adding a few items whenever the user scrolls near the bottom of the list. This provides an 'infinite scrolling' experience. This sample limits the number of items to 2,000.

Learn about Input Controls | ComboBox API Reference

This example uses React.

app.jsx
index.html
app.css
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import 'bootstrap.css'; import '@mescius/wijmo.styles/wijmo.css'; import ReactDOM from 'react-dom/client'; import React from 'react'; import useEvent from 'react-use-event-hook'; import * as wjInput from '@mescius/wijmo.react.input'; const loadItems = (arr, cnt) => { for (let i = 0; i < cnt; i++) { arr.push('item ' + (arr.length + 1)); } return arr; }; const theList = loadItems([], 10); function App() { const initialized = useEvent((combo, e) => { combo.dropDown.addEventListener('scroll', (e) => { // stop adding items when the list reaches 2,000 items if (theList.length < 2000) { let list = e.target; // if the user scrolled near the bottom of the list if (list.scrollTop + list.clientHeight + 100 > list.scrollHeight) { // save scroll top, add items, refresh list, restore scroll top let top = list.scrollTop; loadItems(theList, 5); combo.collectionView.refresh(); list.scrollTop = top; } } }); }); return (<div className="container-fluid"> <wjInput.ComboBox itemsSource={theList} initialized={initialized}/> </div>); } const container = document.getElementById('app'); if (container) { const root = ReactDOM.createRoot(container); root.render(<App />); }
import 'bootstrap.css'; import '@mescius/wijmo.styles/wijmo.css'; import ReactDOM from 'react-dom/client'; import React from 'react'; import useEvent from 'react-use-event-hook'; import * as wjInput from '@mescius/wijmo.react.input'; const loadItems = (arr, cnt) => { for (let i = 0; i < cnt; i++) { arr.push('item ' + (arr.length + 1)); } return arr; }; const theList = loadItems([], 10); function App() { const initialized = useEvent((combo, e) => { combo.dropDown.addEventListener('scroll', (e) => { // stop adding items when the list reaches 2,000 items if (theList.length < 2000) { let list = e.target; // if the user scrolled near the bottom of the list if (list.scrollTop + list.clientHeight + 100 > list.scrollHeight) { // save scroll top, add items, refresh list, restore scroll top let top = list.scrollTop; loadItems(theList, 5); combo.collectionView.refresh(); list.scrollTop = top; } } }); }); return (<div className="container-fluid"> <wjInput.ComboBox itemsSource={theList} initialized={initialized}/> </div>); } const container = document.getElementById('app'); if (container) { const root = ReactDOM.createRoot(container); root.render(<App />); }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>MESCIUS Wijmo ComboBox with Infinite Scrolling</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <!-- SystemJS --> <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.40/system.src.js" integrity="sha512-G6mEj6h18+m3MvzdviSDfPle/TfH0//cXcB33AKlNR/Rha0yQsKefDZKRTkIZos97HEGq2JMV1RT5ybMoQ3WsQ==" crossorigin="anonymous"></script> <script src="systemjs.config.js"></script> <script> System.import('./src/app'); </script> </head> <body> <div id="app"></div> </body> </html>
body { margin-bottom: 24px; }
(function (global) { window.process = { env: { NODE_ENV: "production" } } System.config({ transpiler: 'plugin-babel', babelOptions: { es2015: true, react: true }, meta: { '*.css': { loader: 'css' } }, paths: { // paths serve as alias 'npm:': 'node_modules/' }, // map tells the System loader where to look for things map: { 'jszip': 'npm:jszip/dist/jszip.js', '@mescius/wijmo': 'npm:@mescius/wijmo/index.js', '@mescius/wijmo.input': 'npm:@mescius/wijmo.input/index.js', '@mescius/wijmo.styles': 'npm:@mescius/wijmo.styles', '@mescius/wijmo.cultures': 'npm:@mescius/wijmo.cultures', '@mescius/wijmo.chart': 'npm:@mescius/wijmo.chart/index.js', '@mescius/wijmo.chart.analytics': 'npm:@mescius/wijmo.chart.analytics/index.js', '@mescius/wijmo.chart.animation': 'npm:@mescius/wijmo.chart.animation/index.js', '@mescius/wijmo.chart.annotation': 'npm:@mescius/wijmo.chart.annotation/index.js', '@mescius/wijmo.chart.finance': 'npm:@mescius/wijmo.chart.finance/index.js', '@mescius/wijmo.chart.finance.analytics': 'npm:@mescius/wijmo.chart.finance.analytics/index.js', '@mescius/wijmo.chart.hierarchical': 'npm:@mescius/wijmo.chart.hierarchical/index.js', '@mescius/wijmo.chart.interaction': 'npm:@mescius/wijmo.chart.interaction/index.js', '@mescius/wijmo.chart.radar': 'npm:@mescius/wijmo.chart.radar/index.js', '@mescius/wijmo.chart.render': 'npm:@mescius/wijmo.chart.render/index.js', '@mescius/wijmo.chart.webgl': 'npm:@mescius/wijmo.chart.webgl/index.js', '@mescius/wijmo.chart.map': 'npm:@mescius/wijmo.chart.map/index.js', '@mescius/wijmo.gauge': 'npm:@mescius/wijmo.gauge/index.js', '@mescius/wijmo.grid': 'npm:@mescius/wijmo.grid/index.js', '@mescius/wijmo.grid.detail': 'npm:@mescius/wijmo.grid.detail/index.js', '@mescius/wijmo.grid.filter': 'npm:@mescius/wijmo.grid.filter/index.js', '@mescius/wijmo.grid.search': 'npm:@mescius/wijmo.grid.search/index.js', '@mescius/wijmo.grid.style': 'npm:@mescius/wijmo.grid.style/index.js', '@mescius/wijmo.grid.grouppanel': 'npm:@mescius/wijmo.grid.grouppanel/index.js', '@mescius/wijmo.grid.multirow': 'npm:@mescius/wijmo.grid.multirow/index.js', '@mescius/wijmo.grid.transposed': 'npm:@mescius/wijmo.grid.transposed/index.js', '@mescius/wijmo.grid.transposedmultirow': 'npm:@mescius/wijmo.grid.transposedmultirow/index.js', '@mescius/wijmo.grid.pdf': 'npm:@mescius/wijmo.grid.pdf/index.js', '@mescius/wijmo.grid.sheet': 'npm:@mescius/wijmo.grid.sheet/index.js', '@mescius/wijmo.grid.xlsx': 'npm:@mescius/wijmo.grid.xlsx/index.js', '@mescius/wijmo.grid.selector': 'npm:@mescius/wijmo.grid.selector/index.js', '@mescius/wijmo.grid.cellmaker': 'npm:@mescius/wijmo.grid.cellmaker/index.js', '@mescius/wijmo.grid.immutable': 'npm:@mescius/wijmo.grid.immutable/index.js', '@mescius/wijmo.touch': 'npm:@mescius/wijmo.touch/index.js', '@mescius/wijmo.cloud': 'npm:@mescius/wijmo.cloud/index.js', '@mescius/wijmo.nav': 'npm:@mescius/wijmo.nav/index.js', '@mescius/wijmo.odata': 'npm:@mescius/wijmo.odata/index.js', '@mescius/wijmo.olap': 'npm:@mescius/wijmo.olap/index.js', '@mescius/wijmo.rest': 'npm:@mescius/wijmo.rest/index.js', '@mescius/wijmo.pdf': 'npm:@mescius/wijmo.pdf/index.js', '@mescius/wijmo.pdf.security': 'npm:@mescius/wijmo.pdf.security/index.js', '@mescius/wijmo.viewer': 'npm:@mescius/wijmo.viewer/index.js', '@mescius/wijmo.xlsx': 'npm:@mescius/wijmo.xlsx/index.js', '@mescius/wijmo.undo': 'npm:@mescius/wijmo.undo/index.js', '@mescius/wijmo.interop.grid': 'npm:@mescius/wijmo.interop.grid/index.js', '@mescius/wijmo.barcode': 'npm:@mescius/wijmo.barcode/index.js', '@mescius/wijmo.barcode.common': 'npm:@mescius/wijmo.barcode.common/index.js', '@mescius/wijmo.barcode.composite': 'npm:@mescius/wijmo.barcode.composite/index.js', '@mescius/wijmo.barcode.specialized': 'npm:@mescius/wijmo.barcode.specialized/index.js', "@mescius/wijmo.react.chart.analytics": "npm:@mescius/wijmo.react.chart.analytics/index.js", "@mescius/wijmo.react.chart.animation": "npm:@mescius/wijmo.react.chart.animation/index.js", "@mescius/wijmo.react.chart.annotation": "npm:@mescius/wijmo.react.chart.annotation/index.js", "@mescius/wijmo.react.chart.finance.analytics": "npm:@mescius/wijmo.react.chart.finance.analytics/index.js", "@mescius/wijmo.react.chart.finance": "npm:@mescius/wijmo.react.chart.finance/index.js", "@mescius/wijmo.react.chart.hierarchical": "npm:@mescius/wijmo.react.chart.hierarchical/index.js", "@mescius/wijmo.react.chart.interaction": "npm:@mescius/wijmo.react.chart.interaction/index.js", "@mescius/wijmo.react.chart.radar": "npm:@mescius/wijmo.react.chart.radar/index.js", "@mescius/wijmo.react.chart": "npm:@mescius/wijmo.react.chart/index.js", "@mescius/wijmo.react.core": "npm:@mescius/wijmo.react.core/index.js", '@mescius/wijmo.react.chart.map': 'npm:@mescius/wijmo.react.chart.map/index.js', "@mescius/wijmo.react.gauge": "npm:@mescius/wijmo.react.gauge/index.js", "@mescius/wijmo.react.grid.detail": "npm:@mescius/wijmo.react.grid.detail/index.js", "@mescius/wijmo.react.grid.filter": "npm:@mescius/wijmo.react.grid.filter/index.js", "@mescius/wijmo.react.grid.grouppanel": "npm:@mescius/wijmo.react.grid.grouppanel/index.js", '@mescius/wijmo.react.grid.search': 'npm:@mescius/wijmo.react.grid.search/index.js', "@mescius/wijmo.react.grid.multirow": "npm:@mescius/wijmo.react.grid.multirow/index.js", "@mescius/wijmo.react.grid.sheet": "npm:@mescius/wijmo.react.grid.sheet/index.js", '@mescius/wijmo.react.grid.transposed': 'npm:@mescius/wijmo.react.grid.transposed/index.js', '@mescius/wijmo.react.grid.transposedmultirow': 'npm:@mescius/wijmo.react.grid.transposedmultirow/index.js', '@mescius/wijmo.react.grid.immutable': 'npm:@mescius/wijmo.react.grid.immutable/index.js', "@mescius/wijmo.react.grid": "npm:@mescius/wijmo.react.grid/index.js", "@mescius/wijmo.react.input": "npm:@mescius/wijmo.react.input/index.js", "@mescius/wijmo.react.olap": "npm:@mescius/wijmo.react.olap/index.js", "@mescius/wijmo.react.viewer": "npm:@mescius/wijmo.react.viewer/index.js", "@mescius/wijmo.react.nav": "npm:@mescius/wijmo.react.nav/index.js", "@mescius/wijmo.react.base": "npm:@mescius/wijmo.react.base/index.js", '@mescius/wijmo.react.barcode.common': 'npm:@mescius/wijmo.react.barcode.common/index.js', '@mescius/wijmo.react.barcode.composite': 'npm:@mescius/wijmo.react.barcode.composite/index.js', '@mescius/wijmo.react.barcode.specialized': 'npm:@mescius/wijmo.react.barcode.specialized/index.js', 'jszip': 'npm:jszip/dist/jszip.js', 'react': 'npm:react/index.js', 'react-dom': 'npm:react-dom/index.js', 'react-dom/client': 'npm:react-dom/client.js', "scheduler": "npm:scheduler/index.js", 'redux': 'npm:redux/dist/redux.min.js', 'react-redux': 'npm:react-redux/dist/react-redux.min.js', 'bootstrap.css': 'npm:bootstrap/dist/css/bootstrap.min.css', 'css': 'npm:systemjs-plugin-css/css.js', 'plugin-babel': 'npm:systemjs-plugin-babel/plugin-babel.js', 'systemjs-babel-build':'npm:systemjs-plugin-babel/systemjs-babel-browser.js', "react-use-event-hook": "npm:react-use-event-hook/dist/esm/useEvent.js", }, // packages tells the System loader how to load when no filename and/or no extension packages: { src: { defaultExtension: 'jsx' }, "node_modules": { defaultExtension: 'js' }, } }); })(this);