Demos
Input(Angular)
ComboBox
Infinite Scrolling

ComboBox with Infinite Scrolling (Angular)

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 Angular.

JavaScript
Angular
Vue
React
app.component.ts
index.html
app.component.html
styles.css
Copy to CodeMine
import 'bootstrap.css';
import '@mescius/wijmo.styles/wijmo.css';
import './styles.css';
//
import * as wijmo from '@mescius/wijmo';
import * as input from '@mescius/wijmo.input';
//
import '@angular/compiler';
import { Component, enableProdMode, Inject, ɵresolveComponentResources } from '@angular/core';

import { BrowserModule, bootstrapApplication } from '@angular/platform-browser';
import { WjInputModule } from '@mescius/wijmo.angular2.input';
//
@Component({
  standalone: true,
  imports: [WjInputModule, BrowserModule],
  selector: 'app-component',
  templateUrl: 'src/app.component.html',
})
export class AppComponent {
  theList: any[];
  //
  constructor() {
    // list that contains the items in the Combo (start with 10 items)
    this.theList = this._loadItems([], 10);
  }
  //
  initialized(combo: input.ComboBox) {
    combo.dropDown.addEventListener('scroll', (e) => {
      // stop adding items when the list reaches 2,000 items
      if (this.theList.length < 2000) {
        let list = <Element>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;
          this._loadItems(this.theList, 5);
          combo.collectionView.refresh();
          list.scrollTop = top;
        }
      }
    });
  }
  //
  private _loadItems(arr: any[], cnt: number) {
    for (let i = 0; i < cnt; i++) {
      arr.push('item ' + (arr.length + 1));
    }
    return arr;
  }
}
//

//
enableProdMode();

// Resolve resources (templateUrl, styleUrls etc), After resolution all URLs have been converted into `template` strings.
ɵresolveComponentResources(fetch).then(() => {
  // Bootstrap application
  bootstrapApplication(AppComponent).catch((err) => console.error(err));
});
import 'bootstrap.css'; import '@mescius/wijmo.styles/wijmo.css'; import './styles.css'; // import * as wijmo from '@mescius/wijmo'; import * as input from '@mescius/wijmo.input'; // import '@angular/compiler'; import { Component, enableProdMode, Inject, ɵresolveComponentResources } from '@angular/core'; import { BrowserModule, bootstrapApplication } from '@angular/platform-browser'; import { WjInputModule } from '@mescius/wijmo.angular2.input'; // @Component({ standalone: true, imports: [WjInputModule, BrowserModule], selector: 'app-component', templateUrl: 'src/app.component.html', }) export class AppComponent { theList: any[]; // constructor() { // list that contains the items in the Combo (start with 10 items) this.theList = this._loadItems([], 10); } // initialized(combo: input.ComboBox) { combo.dropDown.addEventListener('scroll', (e) => { // stop adding items when the list reaches 2,000 items if (this.theList.length < 2000) { let list = <Element>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; this._loadItems(this.theList, 5); combo.collectionView.refresh(); list.scrollTop = top; } } }); } // private _loadItems(arr: any[], cnt: number) { for (let i = 0; i < cnt; i++) { arr.push('item ' + (arr.length + 1)); } return arr; } } // // enableProdMode(); // Resolve resources (templateUrl, styleUrls etc), After resolution all URLs have been converted into `template` strings. ɵresolveComponentResources(fetch).then(() => { // Bootstrap application bootstrapApplication(AppComponent).catch((err) => console.error(err)); });
<!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"> <!-- Polyfills --> <script src="node_modules/core-js/client/shim.min.js"></script> <script src="node_modules/zone.js/fesm2015/zone.min.js"></script> <!-- SystemJS --> <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.21.5/system.src.js" integrity="sha512-skZbMyvYdNoZfLmiGn5ii6KmklM82rYX2uWctBhzaXPxJgiv4XBwJnFGr5k8s+6tE1pcR1nuTKghozJHyzMcoA==" crossorigin="anonymous"></script> <script src="systemjs.config.js"></script> <script> // workaround to load 'rxjs/operators' from the rxjs bundle System.import('rxjs').then(function (m) { System.set(SystemJS.resolveSync('rxjs/operators'), System.newModule(m.operators)); System.import('./src/app.component'); }); </script> </head> <body> <app-component></app-component> </body> </html>
<div class="container-fluid"> <wj-combo-box #theCombo [itemsSource]="theList" (initialized)="initialized(theCombo)"> </wj-combo-box> </div>
body { margin-bottom: 24px; }
(function (global) { SystemJS.config({ transpiler: './plugin-typescript.js', typescriptOptions: { "target": "ES2022", "module": "system", "emitDecoratorMetadata": true, "experimentalDecorators": true, }, baseURL: 'node_modules/', meta: { 'typescript': { "exports": "ts" }, '*.css': { loader: 'systemjs-plugin-css' }, '*.mjs': { format: 'esm' }, }, paths: { // paths serve as alias 'npm:': '' }, packageConfigPaths: [ '/node_modules/*/package.json', "/node_modules/@angular/*/package.json", "/node_modules/@mescius/*/package.json" ], map: { 'core-js': 'https://cdn.jsdelivr.net/npm/core-js@2.6.12/client/shim.min.js', 'typescript': 'https://cdnjs.cloudflare.com/ajax/libs/typescript/5.2.2/typescript.min.js', "rxjs": "https://cdnjs.cloudflare.com/ajax/libs/rxjs/7.8.1/rxjs.umd.min.js", 'systemjs-plugin-css': 'https://cdn.jsdelivr.net/npm/systemjs-plugin-css@0.1.37/css.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.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.touch': 'npm:@mescius/wijmo.touch/index.js', '@mescius/wijmo.cloud': 'npm:@mescius/wijmo.cloud/index.js', '@mescius/wijmo.barcode': 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'npm:@mescius/wijmo.angular2.barcode.specialized/index.js', 'bootstrap.css': 'npm:bootstrap/dist/css/bootstrap.min.css', 'jszip': 'https://cdnjs.cloudflare.com/ajax/libs/jszip/3.10.1/jszip.min.js', '@angular/core': 'npm:@angular/core/fesm2022/core.mjs', '@angular/core/primitives/signals': 'npm:@angular/core/fesm2022/primitives/signals.mjs', '@angular/core/primitives/event-dispatch': 'npm:@angular/core/fesm2022/primitives/event-dispatch.mjs', '@angular/common': 'npm:@angular/common/fesm2022/common.mjs', '@angular/common/http': 'npm:@angular/common/fesm2022/http.mjs', '@angular/compiler': 'npm:@angular/compiler/fesm2022/compiler.mjs', '@angular/platform-browser': 'npm:@angular/platform-browser/fesm2022/platform-browser.mjs', '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/fesm2022/platform-browser-dynamic.mjs', '@angular/http': 'npm:@angular/http/fesm2022/http.mjs', '@angular/router': 'npm:@angular/router/fesm2022/router.mjs', '@angular/forms': 'npm:@angular/forms/fesm2022/forms.mjs', }, // packages tells the System loader how to load when no filename and/or no extension packages: { "./src": { defaultExtension: 'ts' }, "node_modules": { defaultExtension: 'js' }, wijmo: { defaultExtension: 'js', } } }); })(this);