wasp/web/docs/project/client-config.md

title
Client Config

import { ShowForTs, ShowForJs } from '@site/src/components/TsJsHelpers'

You can configure the client using the client field inside the app declaration:

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.jsx",
    setupFn: import mySetupFunction from "@client/myClientSetupCode.js"
  }
}

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.tsx",
    setupFn: import mySetupFunction from "@client/myClientSetupCode.ts"
  }
}

Root Component

Wasp gives you the option to define a "wrapper" component for your React app.

It can be used for a variety of purposes, but the most common ones are:

• Defining a common layout for your application.
• Setting up various providers that your application needs.

Defining a Common Layout

Let's define a common layout for your application:

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.jsx",
  }
}

export default function Root({ children }) {
  return (
    <div>
      <header>
        <h1>My App</h1>
      </header>
      {children}
      <footer>
        <p>My App footer</p>
      </footer>
    </div>
  )
}

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.tsx",
  }
}

export default function Root({ children }: { children: React.ReactNode }) {
  return (
    <div>
      <header>
        <h1>My App</h1>
      </header>
      {children}
      <footer>
        <p>My App footer</p>
      </footer>
    </div>
  )
}

Setting up a Provider

This is how to set up various providers that your application needs:

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.jsx",
  }
}

import store from './store'
import { Provider } from 'react-redux'

export default function Root({ children }) {
  return <Provider store={store}>{children}</Provider>
}

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.tsx",
  }
}

import store from './store'
import { Provider } from 'react-redux'

export default function Root({ children }: { children: React.ReactNode }) {
  return <Provider store={store}>{children}</Provider>
}

As long as you render the children, you can do whatever you want in your root component.

Read more about the root component in the API Reference.

Setup Function

setupFn declares a TypescriptJavaScript function that Wasp executes on the client before everything else.

Running Some Code

We can run any code we want in the setup function.

For example, here's a setup function that logs a message every hour:

export default async function mySetupFunction() {
  let count = 1
  setInterval(
    () => console.log(`You have been online for ${count++} hours.`),
    1000 * 60 * 60
  )
}

export default async function mySetupFunction(): Promise<void> {
  let count = 1
  setInterval(
    () => console.log(`You have been online for ${count++} hours.`),
    1000 * 60 * 60
  )
}

Overriding Default Behaviour for Queries

:::info You can change the options for a single Query using the options object, as described here. :::

Wasp's useQuery hook uses react-query's useQuery hook under the hood. Since react-query comes configured with aggressive but sane default options, you most likely won't have to change those defaults for all Queries.

If you do need to change the global defaults, you can do so inside the client setup function.

Wasp exposes a configureQueryClient hook that lets you configure react-query's QueryClient object:

import { configureQueryClient } from '@wasp/queryClient'

export default async function mySetupFunction() {
  // ... some setup
  configureQueryClient({
    defaultOptions: {
      queries: {
        staleTime: Infinity,
      },
    },
  })
  // ... some more setup
}

import { configureQueryClient } from '@wasp/queryClient'

export default async function mySetupFunction(): Promise<void> {
  // ... some setup
  configureQueryClient({
    defaultOptions: {
      queries: {
        staleTime: Infinity,
      },
    },
  })
  // ... some more setup
}

Make sure to pass in an object expected by the QueryClient's constructor, as explained in react-query's docs.

Read more about the setup function in the API Reference.

API Reference

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.jsx",
    setupFn: import mySetupFunction from "@client/myClientSetupCode.js"
  }
}

app MyApp {
  title: "My app",
  // ...
  client: {
    rootComponent: import Root from "@client/Root.tsx",
    setupFn: import mySetupFunction from "@client/myClientSetupCode.ts"
  }
}

Client has the following options:

• rootComponent: ClientImport

  rootComponent defines the root component of your client application. It is expected to be a React component, and Wasp will use it to wrap your entire app. It must render its children, which are the actual pages of your application.

  Here's an example of a root component that both sets up a provider and renders a custom layout:

  import store from './store'
  import { Provider } from 'react-redux'
  
  export default function Root({ children }) {
    return (
      <Provider store={store}>
        <Layout>{children}</Layout>
      </Provider>
    )
  }
  
  function Layout({ children }) {
    return (
      <div>
        <header>
          <h1>My App</h1>
        </header>
        {children}
        <footer>
          <p>My App footer</p>
        </footer>
      </div>
    )
  }
  

  import store from './store'
  import { Provider } from 'react-redux'
  
  export default function Root({ children }: { children: React.ReactNode }) {
    return (
      <Provider store={store}>
        <Layout>{children}</Layout>
      </Provider>
    )
  }
  
  function Layout({ children }: { children: React.ReactNode }) {
    return (
      <div>
        <header>
          <h1>My App</h1>
        </header>
        {children}
        <footer>
          <p>My App footer</p>
        </footer>
      </div>
    )
  }
  

• setupFn: ClientImport

  setupFn declares a Typescript function that Wasp executes on the client before everything else. It is expected to be asynchronous, and Wasp will await its completion before rendering the page. The function takes no arguments, and its return value is ignored.

  setupFn declares a JavaScript function that Wasp executes on the client before everything else. It is expected to be asynchronous, and Wasp will await its completion before rendering the page. The function takes no arguments, and its return value is ignored.

  You can use this function to perform any custom setup (e.g., setting up client-side periodic jobs).

  export default async function mySetupFunction() {
    // Run some code
  }
  

  export default async function mySetupFunction(): Promise<void> {
    // Run some code
  }