Event-Based Validation (React)

The FlexGrid helps with validation in several ways.

Automatic Type Coercion, Data Maps, Event-Based Validation, and CollectionView-Based Validation.

The grid below demonstrates the three first items. It has a Country column with a data map that prevents users from entering invalid countries. The cellEditEnding event is used to ensure that the 'Sales' and 'Expenses' columns contain positive values.

This example uses React.

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './app.css'; // import * as React from 'react'; import * as ReactDOM from 'react-dom'; import { FlexGrid, FlexGridColumn } from '@grapecity/wijmo.react.grid'; import { changeType, DataType, isNumber } from '@grapecity/wijmo'; class App extends React.Component { constructor(props) { super(props); this.countries = ['US', 'Germany', 'UK', 'Japan', 'Italy', 'Greece']; this.state = { data: this.getData() }; } render() { return <div className="container-fluid"> <FlexGrid initialized={this.initializeGrid.bind(this)} itemsSource={this.state.data}> <FlexGridColumn binding="id" header="ID" width={50} isReadOnly={true}/> <FlexGridColumn binding="country" header="Country" isRequired={true} dataMap={this.countries}/> <FlexGridColumn binding="sales" header="Sales" format="n2"/> <FlexGridColumn binding="expenses" header="Expenses" format="n2"/> <FlexGridColumn binding="overdue" header="Overdue"/> </FlexGrid> </div>; } // event-based validation initializeGrid(flex) { flex.cellEditEnding.addHandler((s, e) => { let col = s.columns[e.col]; if (col.binding == 'sales' || col.binding == 'expenses') { let value = changeType(s.activeEditor.value, DataType.Number, col.format); if (!isNumber(value) || value < 0) { e.cancel = true; e.stayInEditMode = true; alert('Please enter a positive amount.'); } } }); } // create some random data getData() { let data = []; for (let i = 0; i < this.countries.length; i++) { data.push({ id: i, country: this.countries[i], sales: Math.random() * 10000, expenses: Math.random() * 5000, overdue: i % 4 == 0 }); } return data; } } ReactDOM.render(<App />, document.getElementById('app'));
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>GrapeCity Wijmo FlexGrid Validation</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 id="app"></div> </body> </html>
.wj-flexgrid { max-height: 200px; margin-bottom: 12px; } body { margin-bottom: 24px; }
(function (global) { 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', '@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', 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packages: { src: { defaultExtension: 'jsx' }, "node_modules": { defaultExtension: 'js' }, } }); })(this);