@aglyn/shared-util-next

React hooks and helpers for carrying a ?continue= return URL through a Next.js App Router sign-in flow without creating an open redirect. It is used by Aglyn's console sign-in pages and is usable in any App Router app.

Published to npm from the Aglyn monorepo. Versions follow semantic versioning.

Install

npm install @aglyn/shared-util-next

Peer dependencies: next (16.3.3) and react (^19.2.8).

What's in it

One client module ('use client'), use-continue-url, re-exported from the package root:

• useContinueUrl() - returns [encoded, decoded, pushNext]: the current pathname URL-encoded (to put into a link to the sign-in page), the validated continue value from the query string (or ''), and a function that navigates to it.
• useContinueUrlDecoded() - [decoded, pushNext]. pushNext(url = '/') goes to the continue URL when there is a safe one, otherwise to url. Relative targets use router.push; absolute ones use window.location.assign.
• useContinueUrlEncoded() - the encoded current pathname only.
• useContinueHref(path) - an href for a link out of the current page that keeps the continue value. Reads only useSearchParams, not the router.
• withContinueUrl(path, continueUrl) - the same, as a plain function. Unsafe or empty values append nothing.
• isSafeContinueUrl(url) - the predicate behind all of the above.
• ContinueParamName ('continue') and continueParam(value).

A continue URL is accepted when it is a relative path that resolves onto the current origin (checked with isSameOriginPath from @aglyn/shared-util-http/safe-redirect), or an absolute https: URL whose host is the workspace domain or a subdomain of it. The workspace domain comes from NEXT_PUBLIC_WORKSPACE_DOMAIN and defaults to aglyn.com, so set that variable when you use this outside Aglyn. Everything else is treated as absent.

Usage

'use client'

import { useContinueHref, useContinueUrlDecoded } from '@aglyn/shared-util-next'

export function AfterSignIn() {
  const [, pushNext] = useContinueUrlDecoded()
  const ssoHref = useContinueHref('/sso')

  return (
    <>
      <button onClick={() => pushNext('/dashboard')}>Continue</button>
      <a href={ssoHref}>Use single sign-on</a>
    </>
  )
}

The hooks call useSearchParams, so render them under a Suspense boundary as Next.js requires.

How it fits

A shared package: generic, with no knowledge of Aglyn's model. Shared packages may only import other shared packages; this one depends on @aglyn/shared-util-http. No other library in the monorepo depends on it; the console app uses it directly.

License

Apache-2.0. Source: https://github.com/aglyn/aglyn/tree/main/libs/shared/util/next