Preserve Row Heights

When the data source changes, the FlexGrid control automatically re-generates all rows, and resets their sizes to the original values. This sample shows how you can preserve the row heights when the data is refreshed. It uses the loadingRows event to save the original row heights and the loadedRows event to restore them.

Learn about FlexGrid | FlexGrid API Reference

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './styles.css'; import * as wjGrid from '@grapecity/wijmo.grid'; import { getData } from './data'; // document.readyState === 'complete' ? init() : window.onload = init; // function init() { // // create the grid var theGrid = new wjGrid.FlexGrid('#theGrid', { itemsSource: getData(), allowResizing: 'Both' }); // // preserve row heights when refreshing the data var heightMap = null; theGrid.loadingRows.addHandler(function (s, e) { heightMap = new Map(); theGrid.rows.forEach(function (row) { heightMap.set(row.dataItem, row.height); }); console.log('saved'); }); theGrid.loadedRows.addHandler(function (s, e) { theGrid.rows.forEach(function (row) { var height = heightMap.get(row.dataItem); if (height != null) { row.height = height; } }); console.log('restored'); }); // // force a data reload document.getElementById('reload').addEventListener('click', function () { theGrid.collectionView.refresh(); }); }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>MESCIUS Wijmo FlexGrid Preserve Row Height</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"> <button id="reload" class="btn btn-default"> Reload </button> <div id="theGrid"> </div> </body> </html>
// create some random data export function getData() { var countries = 'US,Germany,UK,Japan,Italy,Greece'.split(','), data = []; for (var i = 0; i < 200; i++) { data.push({ id: i, country: countries[i % countries.length], active: i % 5 != 0, downloads: Math.round(Math.random() * 200000), sales: Math.random() * 100000, expenses: Math.random() * 50000 }); } return data; }
.wj-flexgrid { max-height: 250px; margin: 6px 0; }
(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.chart.map': 'npm:@grapecity/wijmo.chart.map/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.transposedmultirow': 'npm:@grapecity/wijmo.grid.transposedmultirow/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.rest': 'npm:@grapecity/wijmo.rest/index.js', '@grapecity/wijmo.pdf': 'npm:@grapecity/wijmo.pdf/index.js', '@grapecity/wijmo.pdf.security': 'npm:@grapecity/wijmo.pdf.security/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', '@grapecity/wijmo.barcode': 'npm:@grapecity/wijmo.barcode/index.js', '@grapecity/wijmo.barcode.common': 'npm:@grapecity/wijmo.barcode.common/index.js', '@grapecity/wijmo.barcode.composite': 'npm:@grapecity/wijmo.barcode.composite/index.js', '@grapecity/wijmo.barcode.specialized': 'npm:@grapecity/wijmo.barcode.specialized/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);