React Native & Expo

formkrafter-react-native renders the same form specs as the web packages with native components — no WebView, no Web Components. Validation, rules, option sources and the recap walk all come from formkrafter-core, so a spec built in the web builder renders on the phone unchanged.

It is a renderer: there is no mobile builder, by design.

Install

Expo

npx expo install @streamline-pulse/formkrafter-react-native

Bare React Native

npm install @streamline-pulse/formkrafter-react-native

React ≥18 and React Native ≥0.76 are peer dependencies. Nothing else is required for the core bricks — the date, file and signature bricks each live behind an opt-in entry point.

First render

1. Wrap your app in the theme provider:

   import { FkThemeProvider } from '@streamline-pulse/formkrafter-react-native'
   
   <FkThemeProvider theme={colorScheme === 'dark' ? 'dark' : 'light'}>
     <App />
   </FkThemeProvider>

2. Render a spec:

   import { useRef } from 'react'
   import { FormRenderer } from '@streamline-pulse/formkrafter-react-native'
   import type { FormRendererHandle } from '@streamline-pulse/formkrafter-react-native'
   
   function Checkout({ spec }) {
     const form = useRef<FormRendererHandle>(null)
   
     return (
       <FormRenderer
         ref={form}
         spec={spec}
         onDataChange={(data, isValid) => console.log(data, isValid)}
         onSubmit={(data, isValid) => isValid && send(data)}
       />
     )
   }

3. Validate on demand through the ref:

   const result = form.current?.validate()
   // { valid: boolean, errors: { fieldKey: message, … } }

A wizard spec (panel:stepper) renders with per-step validation and its own submit button, which calls your onSubmit — no extra wiring. Grid rows count in the global verdict.

Theming

FkThemeProvider accepts 'light', 'dark' or a full token table — the same values the web exposes as CSS custom properties:

import { fkDarkTheme } from '@streamline-pulse/formkrafter-react-native'

<FkThemeProvider theme={{ ...fkDarkTheme, colorPrimary: '#e0662d' }}>

Languages

Two independent knobs, identical to the web:

• Chrome strings (stepper buttons, grid actions, select search…) come from the shared store: setFkTranslations(frFkTranslations) from formkrafter-core.
• Field labels written as { en: 'Full name', fr: 'Nom complet' } resolve through the locale prop on FormRenderer.

Switch both without remounting — the entered data stays.

Bricks that need a native module

Metro resolves imports statically, so bricks that depend on a native module live on their own entry points. Install the module, call the registration once at startup; applications that skip a brick never resolve its module.

Entry point	Native module	Registration
…/date	@react-native-community/datetimepicker	registerNativeDateBricks()
…/file	expo-document-picker	registerNativeFileBrick()
…/signature	react-native-svg	registerNativeSignatureBrick()

import { registerNativeDateBricks } from '@streamline-pulse/formkrafter-react-native/date'

registerNativeDateBricks()

File uploads go through core’s fileUploadService — the same injection point as the web — and the signature stores an image/svg+xml data URL where the web’s canvas produces PNG.

Custom bricks and UI kits

The registry is the extension point. A brick receives data, error, disabled, resolved configs and onDataChange, and renders whatever it wants — gluestack, NativeBase, Tamagui or your own components:

import {
  createNativeBrick,
  registerNativeBrick,
} from '@streamline-pulse/formkrafter-react-native'

registerNativeBrick(
  createNativeBrick({
    type: 'input',
    id: 'rating',
    render: (props) => (
      <Stars value={props.data} onChange={props.onDataChange} error={props.error} />
    ),
  }),
)

Register before the first render to replace a built-in — the defaults never clobber an existing registration. Bricks without a native renderer show an explicit placeholder rather than failing.

Tip

The engine itself is exported: FormEngine is a framework-free class (state, touched tracking, rules, validation) and useFormEngine its React binding — useful for headless flows or custom renderers.

Next steps

Form specsThe spec format both renderers share.

Packages referenceEverything the react-native package exports, and the brick coverage.

ServicesRemote options, file uploads and nested forms — all injectable.