Launch-time initialization in Next.js static/exported site - next.js

Question

I'm trying to use Next to power an Electron app. electron-next uses Next's static site mode for its production build, which calls getInitialProps at build-time, rather than launch-time.
start.js (initially rendered page)
import Link from 'next/link'
export default function Start({date}) {
return (
<div>
<div>Date is {date}</div> {/* <- will always be the build time */}
<Link href="/about">
<a>Take me to the About page</a>
</Link>
</div>
)
}
Start.getInitialProps = () => {
return {
date: "" + new Date()
}
}
Interestingly, using Link to navigate elsewhere does, in fact, result in a dynamic getInitialProps call.
about.js
import Link from 'next/link'
export default function About({date}) {
return (
<div>
<div>Date is {date}</div> {/* <- will be the time the link was clicked */}
<div>Important info about this app</div>
</div>
)
}
About.getInitialProps = () => {
return {
date: "" + new Date()
}
}
Is there a non-hacky way to get dynamic behavior for the initial route? I imagine this would have plenty of use cases in static sites, too.

Answer 1

I ended up not using getInitialProps at all. Instead, I'm using a React hook. It works basically like this:
async function useModel() {
const modelRef = useRef(null)
// This hook will render at build-time by Next.js's static site, in which
// case the conditional loading of the model will never happen.
//
// At startup-time, it will be re-renderered on the Electron renderer thread,
// at which time, we'll actually want to load data.
if (process.browser && !modelRef.current) {
const m = new Model()
await m.init() // <- Assumed to have some async fetching logic
modelRef.current = m
}
return modelRef.current
}
Then, the top-level component can easily use the presence of the model to determine what to do next:
function Start() {
const model = useModel()
if (!model) {
return <div>Loading...</div>
} else {
return <MyProperUI model={model} />
}
}
Or, you could easily rig it up to show an unpopulated default UI, or whatever.
So basically, use getInitialProps for code you want to run exactly once, server-side/build-time or client-side. Otherwise, use other means of initialization. As seen here, hooks allow for this with pretty minimal boilerplate.