Hi, I’m trying out the solid-client-authn-node application for a Node.js backend service.
I’ve followed all the Inrupt tutorials but I got stuck with the authorized requests.
https://docs.inrupt.com/developer-tools/javascript/client-libraries/using-libraries/
As mentioned in the tutorials, while performing authorized requests we should always pass the fetch function from the authorized Session to the solid-client methods.
So in my codebase I wanted to do that, but I keep getting errors while passing the fetch function.
const express = require("express");
const cookieSession = require("cookie-session");
const {
getSessionFromStorage,
getSessionIdFromStorageAll,
Session
} = require("@inrupt/solid-client-authn-node");
const {
access,
getSolidDataset
} = require("@inrupt/solid-client")
const app = express();
const port = 3000;
app.use(express.json());
app.use(express.urlencoded());
// The following snippet ensures that the server identifies each user's session
// with a cookie using an express-specific mechanism
app.use(
cookieSession({
name: "session",
// These keys are required by cookie-session to sign the cookies.
keys: [
"Required, but value not relevant for this demo - key1",
"Required, but value not relevant for this demo - key2",
],
maxAge: 24 * 60 * 60 * 1000, // 24 hours
})
);
// Login endpoint: returns the link to the OIDC provider
app.get('/login', async (req, res) => {
const session = new Session();
req.session.sessionId = session.info.sessionId;
//redirect url and oidc issuer fetched from the request body
const redirectUrl = "http://localhost:3000/handleRedirect"
const oidcIssuer = "https://solidcommunity.net"
//return the link to the OIDC provider
const returnSolidIdentityProviderLoginUrl = (url) => {
res.send(url)
}
await session.login({
redirectUrl: redirectUrl,
oidcIssuer: oidcIssuer,
clientName: "Covid Safe App Cronos",
handleRedirect: returnSolidIdentityProviderLoginUrl
})
});
// OIDC provider redirects back to this endpoint
app.get("/handleRedirect", async (req, res) => {
let code = req.url.split('?')[1]
const session = await getSessionFromStorage(req.session.sessionId);
await session.handleIncomingRedirect(`http://localhost:${port}/handleRedirect?${code}`);
if (session.info.isLoggedIn) {
return res.send(`<p>Logged in with the WebID ${session.info.webId}.</p>`)
}
})
app.get("/fetch", async (req, res) => {
const session = await getSessionFromStorage(req.session.sessionId);
const resource = encodeURI("https://warddriesen.solidcommunity.net/private/private_resource")
if (!session || !session.info.isLoggedIn) {
return res.status(401)
}
if (!resource) {
return res.status(404).json({ error: "Please pass the (encoded) URL of the Resource you want to fetch!" })
}
const data = await getSolidDataset(resource, { fetch: session.fetch })
res.send(data)
})
When I just execute the session fetch function I get the desired result (as shown below). But all the other solid-client functions require a fetch function to be passed in the options object.
app.get("/fetch", async (req, res) => {
const session = await getSessionFromStorage(req.session.sessionId);
const resource = encodeURI("https://warddriesen.solidcommunity.net/private/private_resource")
if (!session || !session.info.isLoggedIn) {
return res.status(401)
}
if (!resource) {
return res.status(404).json({ error: "Please pass the (encoded) URL of the Resource you want to fetch!" })
}
const result = await (await session.fetch(resource)).text()
res.send(result)
})
Hopefully someone can help me on this one 
!
