Controlled Input
Demonstrates Signal ↔ input value synchronization patterns for two-way data binding.
See interactive examples below.
1import { createSignal } from '@barefootjs/dom'2import { Input } from '@/components/ui/input'34const [text, setText] = createSignal('')56<Input7 value={text()}8 onInput={(e) => setText(e.target.value)}9 placeholder="Type something..."10/>11<p>Current value: {text()}</p>#Pattern Overview
The controlled input pattern uses value={signal()} combined with onInput to create two-way binding between a signal and an input element. This pattern enables real-time synchronization and derived computations.
1import { createSignal } from '@barefootjs/dom'2import { Input } from '@/components/ui/input'34const [text, setText] = createSignal('')56<Input7 value={text()}8 onInput={(e) => setText(e.target.value)}9 placeholder="Type something..."10/>11<p>Current value: {text()}</p>#Examples
#Basic Two-Way Binding
Current value:
1import { createSignal } from '@barefootjs/dom'2import { Input } from '@/components/ui/input'34const [text, setText] = createSignal('')56<Input7 value={text()}8 onInput={(e) => setText(e.target.value)}9 placeholder="Type something..."10/>11<p>Current value: {text()}</p>#Character Count
Characters: 0100 remaining
1import { createSignal, createMemo } from '@barefootjs/dom'23const [text, setText] = createSignal('')4const charCount = createMemo(() => text().length)5const remaining = createMemo(() => 100 - text().length)67<Input8 value={text()}9 onInput={(e) => setText(e.target.value)}10/>11<p>Characters: {charCount()}</p>12<p>{remaining()} remaining</p>#Live Preview
Uppercase:
Word count: 0
1import { createSignal, createMemo } from '@barefootjs/dom'23const [text, setText] = createSignal('')4const uppercase = createMemo(() => text().toUpperCase())5const wordCount = createMemo(() => {6 const trimmed = text().trim()7 return trimmed === '' ? 0 : trimmed.split(/\\s+/).length8})910<Input11 value={text()}12 onInput={(e) => setText(e.target.value)}13/>14<p>Uppercase: {uppercase()}</p>15<p>Word count: {wordCount()}</p>#Multi-Input Sync
Shared value:
1import { createSignal } from '@barefootjs/dom'23const [text, setText] = createSignal('')45// Both inputs share the same signal6<Input value={text()} onInput={(e) => setText(e.target.value)} />7<Input value={text()} onInput={(e) => setText(e.target.value)} />8<p>Shared value: {text()}</p>#Key Points
Pattern Structure
value={signal()}- Binds signal value to inputonInput={(e) => setSignal(e.target.value)}- Updates signal on input- Use
createMemofor derived values (character count, transformations)
Use Cases
- Form validation with real-time feedback
- Character/word counters
- Live search/filter
- Synced inputs (e.g., mirrored text fields)