Chaining Filters

The CollectionView.filter property allows you to specify one filtering function for the collection. You can use the results of one filter to create a secondary filter.

This is called chaining and it can be done using another CollectionView, as shown in this example.

You can also use the CollectionView.filters property to add multiple filter funtions to the view. This is a new option that is usually simpler and more efficient than chaining filters.

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './styles.css'; // import * as wijmo from '@grapecity/wijmo'; import * as grid from '@grapecity/wijmo.grid'; import * as gridFilter from '@grapecity/wijmo.grid.filter'; import { getData } from './data'; // document.readyState === 'complete' ? init() : window.onload = init; // function init() { // // create a CollectionView based on the raw data let view = new wijmo.CollectionView(getData()); // // create a second CollectionView based on the first one let view2 = new wijmo.CollectionView(view.items, { collectionChanged: (sender) => { let cnt = document.querySelector('#cnt'); cnt.textContent = wijmo.format('{length:n0}', sender.items); } }); // // show initial item count view2.onCollectionChanged(); // // bind a grid to the second CollectionView let theGrid = new grid.FlexGrid('#theGrid', { itemsSource: view2, alternatingRowStep: 0, headersVisibility: 'Column' }); // // add a filter to the grid (will act on the second CollectionView) var filter = new gridFilter.FlexGridFilter(theGrid); // // update the filter on the first CollectionView when the text changes document.querySelector('#theFilter').addEventListener('input', (e) => { // // update first CollectionView's filter let filterText = e.target.value.toLowerCase(); // view.filter = (item) => { return filterText ? item.country.toLowerCase().indexOf(filterText) > -1 : true; }; // // update second collection view's sourceCollection view2.sourceCollection = view.items; }); }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>GrapeCity CollectionView Chaining Filters</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <!-- SystemJS --> <script src="node_modules/systemjs/dist/system.src.js"></script> <script src="systemjs.config.js"></script> <script> System.import('./src/app'); </script> </head> <body> <div class="container-fluid"> <div class="form-group row"> <div class="col-md-2"> <input id="theFilter" name="filter" class="form-control" placeholder="country filter" /> </div> </div> <p> Result (<span id="cnt"></span> items): </p> <div id="theGrid"> </div> </div> </body> </html>
// export function getData() { let countries = ['US', 'Germany', 'UK', 'Japan', 'Italy', 'Greece'], data = []; // for (let i = 0; i < 1000; i++) { data.push({ id: i, country: countries[i % countries.length], downloads: Math.round(Math.random() * 20000), sales: Math.random() * 10000, expenses: Math.random() * 5000 }); } // return data; }
.wj-flexgrid { max-height: 250px; } label { width: 100% }
(function (global) { System.config({ transpiler: 'plugin-babel', babelOptions: { es2015: 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', '@grapecity/wijmo': 'npm:@grapecity/wijmo/index.js', '@grapecity/wijmo.input': 'npm:@grapecity/wijmo.input/index.js', '@grapecity/wijmo.styles': 'npm:@grapecity/wijmo.styles', '@grapecity/wijmo.cultures': 'npm:@grapecity/wijmo.cultures', '@grapecity/wijmo.chart': 'npm:@grapecity/wijmo.chart/index.js', '@grapecity/wijmo.chart.analytics': 'npm:@grapecity/wijmo.chart.analytics/index.js', '@grapecity/wijmo.chart.animation': 'npm:@grapecity/wijmo.chart.animation/index.js', '@grapecity/wijmo.chart.annotation': 'npm:@grapecity/wijmo.chart.annotation/index.js', '@grapecity/wijmo.chart.finance': 'npm:@grapecity/wijmo.chart.finance/index.js', '@grapecity/wijmo.chart.finance.analytics': 'npm:@grapecity/wijmo.chart.finance.analytics/index.js', '@grapecity/wijmo.chart.hierarchical': 'npm:@grapecity/wijmo.chart.hierarchical/index.js', '@grapecity/wijmo.chart.interaction': 'npm:@grapecity/wijmo.chart.interaction/index.js', '@grapecity/wijmo.chart.radar': 'npm:@grapecity/wijmo.chart.radar/index.js', '@grapecity/wijmo.chart.render': 'npm:@grapecity/wijmo.chart.render/index.js', '@grapecity/wijmo.chart.webgl': 'npm:@grapecity/wijmo.chart.webgl/index.js', '@grapecity/wijmo.gauge': 'npm:@grapecity/wijmo.gauge/index.js', '@grapecity/wijmo.grid': 'npm:@grapecity/wijmo.grid/index.js', '@grapecity/wijmo.grid.detail': 'npm:@grapecity/wijmo.grid.detail/index.js', '@grapecity/wijmo.grid.filter': 'npm:@grapecity/wijmo.grid.filter/index.js', '@grapecity/wijmo.grid.search': 'npm:@grapecity/wijmo.grid.search/index.js', '@grapecity/wijmo.grid.grouppanel': 'npm:@grapecity/wijmo.grid.grouppanel/index.js', '@grapecity/wijmo.grid.multirow': 'npm:@grapecity/wijmo.grid.multirow/index.js', '@grapecity/wijmo.grid.transposed': 'npm:@grapecity/wijmo.grid.transposed/index.js', '@grapecity/wijmo.grid.pdf': 'npm:@grapecity/wijmo.grid.pdf/index.js', '@grapecity/wijmo.grid.sheet': 'npm:@grapecity/wijmo.grid.sheet/index.js', '@grapecity/wijmo.grid.xlsx': 'npm:@grapecity/wijmo.grid.xlsx/index.js', '@grapecity/wijmo.grid.selector': 'npm:@grapecity/wijmo.grid.selector/index.js', '@grapecity/wijmo.grid.cellmaker': 'npm:@grapecity/wijmo.grid.cellmaker/index.js', '@grapecity/wijmo.nav': 'npm:@grapecity/wijmo.nav/index.js', '@grapecity/wijmo.odata': 'npm:@grapecity/wijmo.odata/index.js', '@grapecity/wijmo.olap': 'npm:@grapecity/wijmo.olap/index.js', '@grapecity/wijmo.pdf': 'npm:@grapecity/wijmo.pdf/index.js', '@grapecity/wijmo.viewer': 'npm:@grapecity/wijmo.viewer/index.js', '@grapecity/wijmo.xlsx': 'npm:@grapecity/wijmo.xlsx/index.js', '@grapecity/wijmo.undo': 'npm:@grapecity/wijmo.undo/index.js', '@grapecity/wijmo.interop.grid': 'npm:@grapecity/wijmo.interop.grid/index.js', '@grapecity/wijmo.touch': 'npm:@grapecity/wijmo.touch/index.js', '@grapecity/wijmo.cloud': 'npm:@grapecity/wijmo.cloud/index.js', 'jszip': 'npm:jszip/dist/jszip.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' }, // packages tells the System loader how to load when no filename and/or no extension packages: { src: { defaultExtension: 'js' }, "node_modules": { defaultExtension: 'js' }, } }); })(this);