Usually splitting your app state into pages feels natural but sometimes you'll want to have global state for your app. This is an example on how you can use mobx that also works with our universal rendering approach.
In this example we are going to display a digital clock that updates every second. The first render is happening in the server and then the browser will take over. To illustrate this, the server rendered clock will have a different background color than the client one.
To illustrate SSG and SSR, go to /ssg and /ssr, those pages are using Next.js data fetching methods to get the date in the server and return it as props to the page, and then the browser will hydrate the store and continue updating the date.
The trick here for supporting universal mobx is to separate the cases for the client and the server. When we are on the server we want to create a new store every time, otherwise different users data will be mixed up. If we are in the client we want to use always the same store. That's what we accomplish on store.js.
Page.js component is using the clock store to start and stop the store clock.
Clock.js component is using the clock store to read the time.
StoreProvider.js component is used to instantiate the Store both on the server and on the client.
Both components are using a custom hook useStore to pull in the Store from the provider.
Deploy the example using Vercel:
Execute create-next-app with npm or Yarn to bootstrap the example:
npx create-next-app --example with-mobx-react-lite with-mobx-react-lite-app
# or
yarn create next-app --example with-mobx-react-lite with-mobx-react-lite-appDeploy it to the cloud with Vercel (Documentation).