fix: localize decimal separator

cypress/component/TableCellNumber.cy.js

@@ -0,0 +1,95 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+import { setLocale } from '@nextcloud/l10n'
+
+import TableCellNumber from '../../src/shared/components/ncTable/partials/TableCellNumber.vue'
+import NumberForm from '../../src/shared/components/ncTable/partials/rowTypePartials/NumberForm.vue'
+
+describe('TableCellNumber', () => {
+	beforeEach(() => {
+		setLocale('en_US')
+	})
+
+	it('displays decimals with the current locale separator', () => {
+		setLocale('de_DE')
+
+		mountNumberCell(1.234, { numberDecimals: 3 })
+
+		cy.get('.number-display').should('contain.text', '1,234')
+	})
+
+	it('keeps the configured amount of decimal places', () => {
+		mountNumberCell(1.2, { numberDecimals: 2 })
+
+		cy.get('.number-display').should('contain.text', '1.20')
+	})
+
+	it('clamps out-of-range decimal counts for Intl.NumberFormat', () => {
+		mountNumberCell(1.2, { numberDecimals: 101 })
+
+		cy.get('.number-display').invoke('text').should((text) => {
+			expect(text).to.match(/^1\.20+$/)
+			expect(text.trim().split('.')[1]).to.have.length(100)
+		})
+	})
+
+	it('clamps out-of-range decimal counts when editing row values', () => {
+		mountRowNumberForm(1.2, { numberDecimals: 101 }).then(({ wrapper }) => {
+			expect(wrapper.vm.numberFractionDigits).to.equal(100)
+			expect(wrapper.vm.parseValue('1.234')).to.equal(1.234)
+			expect(wrapper.vm.getStep).to.match(/^\.0+1$/)
+
+			const step = wrapper.vm.getStep
+			expect(step.slice(1, -1)).to.have.length(99)
+		})
+	})
+})
+
+function mountNumberCell(value, columnOverrides = {}) {
+	cy.mount(TableCellNumber, {
+		props: {
+			column: {
+				id: 1,
+				numberDecimals: 0,
+				numberMax: null,
+				numberMin: null,
+				numberPrefix: '',
+				numberSuffix: '',
+				...columnOverrides,
+			},
+			rowId: 1,
+			value,
+		},
+	})
+}
+
+function mountRowNumberForm(value, columnOverrides = {}) {
+	return cy.mount(NumberForm, {
+		props: {
+			column: {
+				id: 1,
+				title: 'Amount',
+				description: '',
+				mandatory: false,
+				numberDecimals: 0,
+				numberDefault: undefined,
+				numberMax: null,
+				numberMin: null,
+				numberPrefix: '',
+				numberSuffix: '',
+				viewColumnInformation: {},
+				...columnOverrides,
+			},
+			value,
+		},
+		global: {
+			components: {
+				RowFormWrapper: {
+					template: '<div><slot /></div>',
+				},
+			},
+		},
+	})
+}

src/shared/components/ncTable/partials/TableCellNumber.vue

@@ -23,6 +23,7 @@
 </template>
 
 <script>
+import { getCanonicalLocale } from '@nextcloud/l10n'
 import cellEditMixin from '../mixins/cellEditMixin.js'
 
 export default {
@@ -42,7 +43,16 @@ export default {
 			if (this.value === null) {
 				return null
 			}
-			return this.value.toFixed(this.column?.numberDecimals)
+			// Intl.NumberFormat only accepts 0..100 fraction digits
+			const raw = Number(this.column?.numberDecimals ?? 0)
+			const fractionDigits = Number.isFinite(raw)
+				? Math.min(100, Math.max(0, Math.trunc(raw)))
+				: 0
+			return new Intl.NumberFormat(getCanonicalLocale(), {
+				maximumFractionDigits: fractionDigits,
+				minimumFractionDigits: fractionDigits,
+				useGrouping: false,
+			}).format(this.value)
 		},
 
 		getStep() {

src/shared/components/ncTable/partials/columnTypePartials/forms/NumberForm.vue

@@ -19,7 +19,7 @@
 					{{ t('tables', 'Decimals') }}
 				</div>
 				<div class="fix-col-4">
-					<input v-model="mutableColumn.numberDecimals" type="number">
+					<input v-model="mutableColumn.numberDecimals" type="number" min="0" max="100" step="1">
 				</div>
 			</div>
 			<div v-if="defaultValueErrorHint !== ''" class="col-4">

src/shared/components/ncTable/partials/rowTypePartials/NumberForm.vue

@@ -43,11 +43,17 @@ export default {
 		'update:value',
 	],
 	computed: {
+		numberFractionDigits() {
+			const raw = Number(this.column?.numberDecimals ?? 0)
+			return Number.isFinite(raw)
+				? Math.min(100, Math.max(0, Math.trunc(raw)))
+				: 0
+		},
 		getStep() {
-			if (this.column?.numberDecimals === 0) {
+			if (this.numberFractionDigits === 0) {
 				return '1'
-			} else if (this.column?.numberDecimals > 0) {
-				return '.' + '0'.repeat(this.column.numberDecimals - 1) + '1'
+			} else if (this.numberFractionDigits > 0) {
+				return '.' + '0'.repeat(this.numberFractionDigits - 1) + '1'
 			} else {
 				return 'any'
 			}
@@ -95,7 +101,7 @@ export default {
 			} else {
 				parsedValue = inputValue
 			}
-			const roundedValue = parsedValue.toFixed(this.column?.numberDecimals)
+			const roundedValue = parsedValue.toFixed(this.numberFractionDigits)
 			let value = parseFloat(roundedValue)
 			if ((this.column?.numberMin !== null && this.column?.numberMin !== undefined) && value < this.column?.numberMin) {
 				value = this.column.numberMin