# Parsing values When the user commits an edit, the editor's DOM value (a string for text / number / date inputs, a boolean for checkboxes) is parsed by `parseEditorValue` into the canonical value for the column's type. > Live demo: Validation while editing - https://svgrid.com/demos/24-validation/ The examples on this page run against these rows: ```svelte ``` ```ts import { parseEditorValue } from '@svgrid/grid' parseEditorValue('text', 'Ada') // 'Ada' parseEditorValue('number', '42') // 42 parseEditorValue('number', '4.5') // 4.5 parseEditorValue('number', 'NaN') // null (rejected - caller decides) parseEditorValue('number', '') // null parseEditorValue('date', '2026-05-27') // '2026-05-27T00:00:00.000Z' parseEditorValue('datetime', '2026-05-27T14:32') // '2026-05-27T14:32:00.000Z' parseEditorValue('checkbox', 'true') // true parseEditorValue('checkbox', true) // true ``` The full source is short and worth reading: [`cell-editors.ts`](https://github.com/sv-grid/sv-grid/blob/main/packages/grid/src/editors/cell-editors.ts). ## Custom parsing with `valueParser` Add a per-column `valueParser` to refine the committed value **after** the built-in `parseEditorValue` coercion, before it is written to the row. Return the final value to store. It runs on every commit and flows through the undo history and `onCellValueChange`. ```ts { field: 'sku', editorType: 'text', // "kb 101" -> "KB-101" valueParser: ({ newValue }) => String(newValue).trim().toUpperCase().replace(/\s+/g, '-') }, { field: 'price', editorType: 'text', format: { type: 'currency', currency: 'USD' }, // accept "$1,299.90" / "1299.9" -> 1299.9 valueParser: ({ newValue, oldValue }) => { const n = Number(String(newValue).replace(/[^0-9.\-]/g, '')) return Number.isFinite(n) ? Math.round(n * 100) / 100 : oldValue } }, { field: 'discount', editorType: 'number', // clamp 0..100, integer valueParser: ({ newValue }) => Math.max(0, Math.min(100, Math.round(Number(newValue) || 0))) }, ``` The callback receives `ValueParserParams`: ```ts type ValueParserParams = { newValue: unknown // value after built-in per-editorType coercion oldValue: unknown // the cell's previous value rawInput: string // the raw string the editor produced (pre-coercion) data: TData // the row object columnId: string } ``` > Live demo: valueParser - transform on commit - https://svgrid.com/demos/175-value-parser/ ## What "null" means `parseEditorValue` returns `null` to signal "could not parse". The grid treats `null` as an empty value and writes it into the cell. If you want **invalid input rejected** (the value reverts to its pre-edit state), intercept before the write - see [Validation](https://svgrid.com/docs/help/editing/validation/). ## Try it `valueParser` runs after the editor's own coercion and before the value reaches your row, so it is the place to normalise input. Type a name in lower case, or a salary with a `k` suffix. ```svelte ``` ## See also - [Saving values](https://svgrid.com/docs/help/editing/saving-values/) - [Validation](https://svgrid.com/docs/help/editing/validation/) --- SvGrid is the Svelte 5 data grid (`npm install @svgrid/grid`, MIT). This page: https://svgrid.com/docs/help/editing/parsing-values/ . All docs: https://svgrid.com/llms.txt