JSX

With Hono, you can utilize JSX syntax to write HTML. The hono/jsx is bundled with Hono and is strictly for Server-Side Rendering (SSR), not for client-side.

Settings

To utilize JSX, modify the tsconfig.json:

tsconfig.json:

json

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "hono/jsx"
  }
}

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "hono/jsx"
  }
}

Alternatively, use the pragma directives:

/** @jsx jsx */
/** @jsxImportSource hono/jsx */

/** @jsx jsx */
/** @jsxImportSource hono/jsx */

For Deno, you have to add the pragmas and import jsx and Fragment:

Deno

/** @jsx jsx */
/** @jsxFrag Fragment */

import { Hono } from 'https://deno.land/x/hono/mod.ts'
import { jsx, Fragment } from 'https://deno.land/x/hono/middleware.ts'

/** @jsx jsx */
/** @jsxFrag Fragment */

import { Hono } from 'https://deno.land/x/hono/mod.ts'
import { jsx, Fragment } from 'https://deno.land/x/hono/middleware.ts'

Usage

index.tsx:

tsx

import type { FC } from 'hono/jsx'

const app = new Hono()

const Layout: FC = (props) => {
  return (
    <html>
      <body>{props.children}</body>
    </html>
  )
}

const Top: FC<{ messages: string[] }> = (props: { messages: string[] }) => {
  return (
    <Layout>
      <h1>Hello Hono!</h1>
      <ul>
        {props.messages.map((message) => {
          return <li>{message}!!</li>
        })}
      </ul>
    </Layout>
  )
}

app.get('/', (c) => {
  const messages = ['Good Morning', 'Good Evening', 'Good Night']
  return c.html(<Top messages={messages} />)
})

import type { FC } from 'hono/jsx'

const app = new Hono()

const Layout: FC = (props) => {
  return (
    <html>
      <body>{props.children}</body>
    </html>
  )
}

const Top: FC<{ messages: string[] }> = (props: { messages: string[] }) => {
  return (
    <Layout>
      <h1>Hello Hono!</h1>
      <ul>
        {props.messages.map((message) => {
          return <li>{message}!!</li>
        })}
      </ul>
    </Layout>
  )
}

app.get('/', (c) => {
  const messages = ['Good Morning', 'Good Evening', 'Good Night']
  return c.html(<Top messages={messages} />)
})

Fragment

Use Fragment to group multiple elements without adding extra nodes:

npmDeno

import { Fragment } from 'hono/jsx'

import { Fragment } from 'hono/jsx'

import { Fragment } from 'https://deno.land/x/hono/middleware.ts'

import { Fragment } from 'https://deno.land/x/hono/middleware.ts'

tsx

const List = () => (
  <Fragment>
    <p>first child</p>
    <p>second child</p>
    <p>third child</p>
  </Fragment>
)

const List = () => (
  <Fragment>
    <p>first child</p>
    <p>second child</p>
    <p>third child</p>
  </Fragment>
)

Inserting Raw HTML

To directly insert HTML, use dangerouslySetInnerHTML:

tsx

app.get('/foo', (c) => {
  const inner = { __html: 'JSX &middot; SSR' }
  const Div = <div dangerouslySetInnerHTML={inner} />
})

app.get('/foo', (c) => {
  const inner = { __html: 'JSX &middot; SSR' }
  const Div = <div dangerouslySetInnerHTML={inner} />
})

Memoization

Optimize your components by memoizing computed strings using memo:

npmDeno

import { memo } from 'hono/jsx'

import { memo } from 'hono/jsx'

import { memo } from 'https://deno.land/x/hono/middleware.ts'

import { memo } from 'https://deno.land/x/hono/middleware.ts'

tsx

import { memo } from 'hono/jsx'

const Header = memo(() => <header>Welcome to Hono</header>)
const Footer = memo(() => <footer>Powered by Hono</footer>)
const Layout = (
  <div>
    <Header />
    <p>Hono is cool!</p>
    <Footer />
  </div>
)

import { memo } from 'hono/jsx'

const Header = memo(() => <header>Welcome to Hono</header>)
const Footer = memo(() => <footer>Powered by Hono</footer>)
const Layout = (
  <div>
    <Header />
    <p>Hono is cool!</p>
    <Footer />
  </div>
)

Integration with html Middleware

Combine the JSX and html middlewares for powerful templating. For in-depth details, consult the html middleware documentation.

tsx

import { Hono } from 'hono'
import { html } from 'hono/html'
import { jsx } from 'hono/jsx'

const app = new Hono()

interface SiteData {
  title: string
  children?: any
}

const Layout = (props: SiteData) => html`<!DOCTYPE html>
  <html>
    <head>
      <title>${props.title}</title>
    </head>
    <body>
      ${props.children}
    </body>
  </html>`

const Content = (props: { siteData: SiteData; name: string }) => (
  <Layout {...props.siteData}>
    <h1>Hello {props.name}</h1>
  </Layout>
)

app.get('/:name', (c) => {
  const { name } = c.req.param()
  const props = {
    name: name,
    siteData: {
      title: 'JSX with html sample',
    },
  }
  return c.html(<Content {...props} />)
})

export default app

import { Hono } from 'hono'
import { html } from 'hono/html'
import { jsx } from 'hono/jsx'

const app = new Hono()

interface SiteData {
  title: string
  children?: any
}

const Layout = (props: SiteData) => html`<!DOCTYPE html>
  <html>
    <head>
      <title>${props.title}</title>
    </head>
    <body>
      ${props.children}
    </body>
  </html>`

const Content = (props: { siteData: SiteData; name: string }) => (
  <Layout {...props.siteData}>
    <h1>Hello {props.name}</h1>
  </Layout>
)

app.get('/:name', (c) => {
  const { name } = c.req.param()
  const props = {
    name: name,
    siteData: {
      title: 'JSX with html sample',
    },
  }
  return c.html(<Content {...props} />)
})

export default app

JSX ​

Settings ​

Usage ​

Fragment ​

Inserting Raw HTML ​

Memoization ​

Integration with html Middleware ​

JSX