Combining with SvelteKit

[hades5a]

Hello,
I would like to combine ltijs with SveltKit 1.0. Main problem is preserving the "ltik". Do you have a suggestion for the best architecture?

[hades5a]

Issue is that SvelteKit uses Server-Side-Rendering. When accessing different routes ltik is needed. Because we are already on the server I cant access the ltik

[roelvanhintum]

For anyone else running into this, as a solution i used a custom server.js for dev (hmr won't work) and production instead of adapter-node's own server.js. We've loaded ltijs in serverless mode on a express-js server on a /lti path so sveltekit can run on root.

Production:

import express from 'express';
import { handler } from './build/handler.js';
import { Provider as lti } from 'ltijs';
import router from './lti-router.js';

const app = express();

// Setup
lti.setup(
  process.env.LTI_SECRET,
  {
    url: process.env.MONGO_URL,
    connection: { user: process.env.MONGO_USER, pass: process.env.MONGO_PASS },
  },
  {
    cookies: {
      secure: true,
      sameSite: 'None',
    },
  },
);

// When receiving successful LTI launch redirects to app
lti.onConnect(async (token, req, res) => {
  lti.redirect(res, '/');
});

// Setup function
const setup = async () => {
  await lti.deploy({ serverless: true });

  lti.app.use(router);

  // Mount Ltijs express app into preexisting express app with /lti prefix
  app.use('/lti', lti.app);

  // Use vite's connect instance as middleware. If you use your own
  // express router (express.Router()), you should use router.use
  app.use(handler);

  /**
   * Register platform
   */
  const platform = await lti.registerPlatform({
    url: process.env.LTI_ISSUER,
    name: 'Platform',
    clientId: process.env.LTI_CLIENTID,
    authenticationEndpoint: process.env.LTI_AUTH_REQUEST_URL,
    accesstokenEndpoint: process.env.LTI_ACCESS_TOKEN_URL,
    authConfig: { method: 'JWK_SET', key: process.env.LTI_PUBLIC_KEYSET_URL },
  });

  // Use this to retrieve the public key when not using the /lti/keys endpoint.
  const rsaKey = await platform.platformPublicKey();
  console.log('Platform public rsa key', rsaKey);

  app.listen(3000, () => {
    console.log('listening on port 3000');
  });
};

setup();

Development

import express from 'express';
import { createServer as createViteServer } from 'vite';
import { Provider as lti } from 'ltijs';
import router from './lti-router.js';

const parentServer = express();

// Create Vite server in middleware mode and configure the app type as
// 'custom', disabling Vite's own HTML serving logic so parent server
// can take control
const vite = await createViteServer({
  server: {
    hmr: {
      server: parentServer,
    },
    middlewareMode: true,
  },
  appType: 'custom',
});

// Setup
lti.setup(
  process.env.LTI_SECRET,
  {
    url: process.env.MONGO_URL,
    connection: { user: process.env.MONGO_USER, pass: process.env.MONGO_PASS },
  },
  {
    cookies: {
      secure: false, // Set secure to true if the testing platform is in a different domain and https is being used
      sameSite: '', // Set sameSite to 'None' if the testing platform is in a different domain and https is being used
    },
    devMode: true, // Set DevMode to true if the testing platform is in a different domain and https is not being used
  },
);

// When receiving successful LTI launch redirects to app
lti.onConnect(async (token, req, res) => {
  console.log('token', JSON.stringify(token), token.platformContext.endpoint.scope);
  lti.redirect(res, '/');
});

// Setup function
const setup = async () => {
  await lti.deploy({ serverless: true });

  // Our LTI router goes into the Ltijs app
  lti.app.use(router);

  // Mount Ltijs express app into preexisting express app with /lti prefix
  parentServer.use('/lti', lti.app);

  // Use vite's connect instance as middleware. If you use your own
  // express router (express.Router()), you should use router.use
  parentServer.use(vite.middlewares);
  // parentServer.use((req, res, next) => {
  //   vite.middlewares.handle(req, res, next);
  // });

  /**
   * Register platform
   */
  const platform = await lti.registerPlatform({
    url: process.env.LTI_ISSUER,
    name: 'Platform',
    clientId: process.env.LTI_CLIENTID,
    authenticationEndpoint: process.env.LTI_AUTH_REQUEST_URL,
    accesstokenEndpoint: process.env.LTI_ACCESS_TOKEN_URL,
    authConfig: { method: 'JWK_SET', key: process.env.LTI_PUBLIC_KEYSET_URL },
  });

  // Use this to retrieve the public key when not using the /lti/keys endpoint.
  const rsaKey = await platform.platformPublicKey();
  console.log('Platform public rsa key', rsaKey);

  parentServer.listen(3000, () => {
    console.log('listening on port 3000');
  });
};

setup();