inertia-node-adapter

Inertia adapter for nodejs - supports Express and Koa.

This is a fork of https://github.com/jordankaerim/inertia-node with added support for koa, flash messages and integration tests that adhere to Inertia protocol.

This also includes a flash middleware for koa and express as a bonus. You can use it or use your own.

Usage

For working examples, see the __tests/testServers folders. It contains two servers in koa and express. Note The code is a bit tangled because it was written for integration tests in mind.

Koa

import { inertiaKoaAdapter as inertia, koaFlash } from 'inertia-node-adapter';
import session from 'koa-session';
import Router from '@koa/router';

const version = '1';

app.use(session({ maxAge: 86400000 }, app));
app.use(koaFlash()); // optional, but requires using middleware session beforehand
app.use(
  inertia({
    version,
    html: getHtml,
    flashMessages: (ctx) => ctx.flash.flashAll(), // optional, depends on the flash middleware used
  })
);
const router = new Router();
// in your router handlers
router.get('/home', async (ctx, next) => {
  // if flash middleware was added.
  ctx.flash.setFlashMessage('success', 'User created successfully');

  ctx.Inertia.render({
    component: 'home',
    props: { name: 1 },
    url: '/home',
    version,
  });
  next();
})
  app.use(router.routes());
  return next();
});

Express usage

import express from 'express';
import session from 'express-session';

const app = express();

app.use(session({ secret: 'secret' }));
const router = express.Router();

router.get('/home', async (req, res, next) => {
  // if flash middleware was added.
  req.flash.setFlashMessage('success', 'User created successfully');

  req.Inertia.render({
    component: 'home',
    props: { name: 1 },
    url: '/home',
    version,
  });
});
app.use(flash());
app.use(
  inertia({
    version,
    html: getHtml,
    flashMessages: (req) => req.flash.flashAll() },
  })
);
app.use(router);

Usage details

inertia-node expects two arguments:

html: a function that receives the Inertia page object and an optional viewData object that you can populate with additional data. The function should return an HTML string.
version (optional): your current asset version

It will return a standard Node.js middleware that you can use with Express.js, Polka etc (or koa if you're using koa adapter). Functions can be accessed from the Inertia object that will be added to the request / context. You can chain functions together but you can't call another function after calling render or redirect.

Note: In your HTML view function make sure to always stringify the page object and include it in the data-page attribute of the HTML node you want to render your JavaScript app in. For more infos on how Inertia works read the protocol on the Inertia website.

API

setViewData(data)

data, Object - An Object of additional data you want to pass to your HTML view function

setViewData can be used to pass additional data to your HTML view function such as the page's title or other meta data.

.use(({ Inertia }, _, next) => {
  Inertia.setViewData({
    title: "Todo App",
    description:"A Web App to Create and Manage To-dos"
  })

  next();
})

// ...

const html = (page, viewData) => `
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width,initial-scale=1" />

    <meta name="description" content="${viewData.description}">
    <title>${viewData.title}</title>

    <link rel="stylesheet" href="/build/bundle.css" />
    <script defer type="module" src="/build/main.js"></script>
  </head>

  <body id="app" data-page='${JSON.stringify(page)}'></body>
</html>
`;

shareProps(props)

props, Object - An object of props you want to include with every render call

Shared props are props that will be combined with the props you pass to the render function. When you call shareProps more than once, props shared from previous calls will be merged with props from any subsequent calls.

.use(({ Inertia }, _, next) => {
  Inertia.shareProps({ username: "ironMan" })
  next();
})
.get("/todo", ({ Inertia }) => {
  Inertia.render({
    component: "Todo",
    props: {
      todo: [
        { text: "Study Korean", done: false },
        { text: "Cook Arabic food", done: false },
      ]
    }
    // JavaScript component on the client will receive
    // {
    //   username: "ironMan",
    //   todo: [
    //     { "Study Korean", done: false },
    //     { "Cook Arabic food", done: false },
    //   ]
    // }
  });
})

setHeaders(headers)

headers, Object - An Object of custom headers you want to include in your response

Add custom headers to your response.

Note: Headers that are required by Inertia take precedence and cannot be overwritten.

.get("/", ({ Inertia }) => {
  Inertia
    .setHeaders({
      token: "7pTgHCv0JgeAyyBRDpUi"
    })
    .render({
      component: "Index",
      props: { username: "ironMan" }
    });
})

setStatusCode(statusCode)

statusCode, number - The response's status code

Change the status code when sending a response. Useful for e.g. when you want to render an error. Headers set from previous calls will be merged with headers set from any subsequent calls.

.get("/", ({ Inertia }) => {
  Inertia.render({
    component: "Index",
    props: { username: "ironMan" }
  });
})
.use(({ Inertia }) => {
  Inertia
    .setStatusCode(404)
    .render({
      component: "Error",
      props: { message: "Page not found" },
    });
})

render(page)

page, Object - the Inertia page object

This function will send your response as either a HTML or JSON string to the client depending on wether the client is requesting your page for the first time or is making a subsequent Inertia request.

The Inertia page object consists of the following properties:

component, string - The name of the JavaScript component to render on the client
props, Object - The page props (data)
url, string - The URL of the route. This will be automatically added by the middleware.
version, string - The asset version. This will be automatically added by the middleware.

.get("/todo", ({ Inertia }) => {
  Inertia.render({
    component: "Todo",
    props: {
      todo: [
        { text: "Study Korean", done: false },
        { text: "Cook Arabic food", done: false },
      ]
    },
  });
})

On Partial Reloads only props requested by the client will be sent. To improve performance on the server you can wrap each prop inside a function so that they will only be evaluated when necessary.

.get("/todo", ({ Inertia }) => {
  const todoArray = async () => await database.getTodo();
  const bookmarks = async () => await database.getBookmarks();

  Inertia.render({
    component: "Todo",
    props: {
      todoArray,
      bookmarks
    },
  });
})

Now when the client only requests todoArray the middleware will hit the database only once and not call bookmarks.

redirect(url)

url, string - The URL to redirect to

Redirect the client to a different URL.

.post("/todo", (req, res) => {
  database.createTodo(req.body);
  req.Inertia.redirect("/todo");
})

Note: Inertia requires you to use a 303 status code when redirecting upon a PUT, PATCH or DELETE request and a 302 status code otherwise. The redirect function will automatically take care of this for you. If you handle redirects yourself make sure to select the correct status code.

Note: Calling setStatusCode before redirect has no effect.

Credits

Jordan Kaerim.