Sharing Data

inertia-sails provides multiple ways to share data with your frontend components.

Request-Scoped Sharing

Use sails.inertia.share() to share data with the current request only:

sails.inertia.share('flash', { success: 'Profile updated!' })
sails.inertia.share('user', currentUser)

This is request-scoped using AsyncLocalStorage, so data won't leak between concurrent requests.

Sharing in Custom Hooks

A common pattern is sharing authenticated user data across all requests:

// api/hooks/custom/index.js
module.exports = function defineCustomHook(sails) {
  return {
    routes: {
      before: {
        'GET /*': {
          skipAssets: true,
          fn: async function (req, res, next) {
            if (req.session.userId) {
              const user = await User.findOne({ id: req.session.userId })
              sails.inertia.share('loggedInUser', user)
            }
            return next()
          }
        }
      }
    }
  }
}

Global Sharing

Use sails.inertia.shareGlobally() for app-wide data that doesn't change per request:

// In hook initialization
sails.inertia.shareGlobally('appName', 'My Application')
sails.inertia.shareGlobally('supportEmail', 'support@example.com')

Global data is included in every Inertia response.

WARNING

Use shareGlobally() sparingly. For user-specific data, always use share() to prevent data leaks between users.

Accessing Shared Data

All shared data is available in your frontend component via page props:

<script setup>
import { usePage } from '@inertiajs/vue3'

const page = usePage()

// Access shared data
const user = page.props.loggedInUser
const appName = page.props.appName
</script>

In React:

import { usePage } from '@inertiajs/react'

function Layout({ children }) {
  const { loggedInUser, appName } = usePage().props

  return (
    <div>
      <nav>Welcome, {loggedInUser?.fullName}</nav>
      {children}
    </div>
  )
}

Lazy Evaluation

Share callbacks are lazily evaluated, allowing you to share expensive computations that are only executed when needed:

sails.inertia.share('permissions', async () => {
  return await Permission.find({ user: req.session.userId })
})

For cached lazy props, see Once Props.