CollectionView-based Validation

The FlexGrid works with the CollectionView class to provide item and collection-level validation.

To use this feature, set the CollectionView's getError property to a function that takes three parameters (the data item being validated, the property to validate, and whether the value is being parsed or has already been stored). The function should return a string describing the error or null if there are no errors.

The grid below has as data source with a getError function that ensures the 'Sales' and 'Expenses' properties of the items contain positive values, and provides meaningful error messages if numeric or date cells cannot be parsed.

To see how CollectionView-based validation works, try entering negative values for 'Sales' or 'Expenses' cells, or strings that cannot be parsed into numbers or dates into numeric/date cells:

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './styles.css'; import { CollectionView, DateTime } from '@grapecity/wijmo'; import { FlexGrid } from '@grapecity/wijmo.grid'; import '@grapecity/wijmo.input'; document.readyState === 'complete' ? init() : window.onload = init; function init() { // CollectionView with validation var view = new CollectionView(getData(), { getError: (item, prop, parsing) => { // parsing errors if (parsing) { return prop == 'date' ? 'Please enter a date in the format "M/d/yyyy".' : 'Please enter a number.'; } // data errors if (prop == 'sales' && item.sales < 0) { return 'Sales cannot be negative!'; } if (prop == 'expenses' && item.expenses < 0) { return 'Expenses cannot be negative!'; } // no errors return null; } }); // show the data in a grid new FlexGrid('#theGrid', { itemsSource: view, columns: [ { binding: 'id', header: 'ID', isReadOnly: true }, { binding: 'country', header: 'Country', isRequired: true, dataMap: getCountries() }, { binding: 'sales', header: 'Sales' }, { binding: 'expenses', header: 'Expenses' }, { binding: 'date', header: 'Date', isRequired: true, format: 'M/d/yyyy' }, { binding: 'overdue', header: 'Overdue' } ] }); // create some random data function getCountries() { return 'US,Germany,UK,Japan,Sweden,Norway,Denmark'.split(','); } function getData() { let countries = getCountries(), today = new Date(), data = []; for (let i = 0; i < countries.length; i++) { data.push({ id: i, country: countries[i], sales: Math.random() * 10000, expenses: Math.random() * 5000, date: DateTime.addDays(today, -Math.random() * 360), overdue: (i + 1) % 4 == 0 }); } return data; } }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>GrapeCity Wijmo FlexGrid CollectionView 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 class="container-fluid"> <div id="theGrid"> </div> </div> </body> </html>
.wj-flexgrid { max-height: 200px; margin-bottom: 12px; } body { margin-bottom: 24px; }
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