Session - Sessions for Deno Web Frameworks

Session adds the ability to use sessions with deno web frameworks. Session is very easy to use and takes inspiration from the express-sessions library. Session currently supports the following deno web frameworks:

Session allows you to specify the store used to store session data. Session currently supports the following stores:

MemoryStore: Stores all session data within memory. Good for debugging and testing, but should not be used in production.
SqliteStore: Uses a SQLite database to store session data. Internally, the deno sqlite library is used to interact with a SQLite database. Requires filesystem access.
RedisStore: Uses a Redis database to store session data. Internally, the deno redis library is used to interact with a Redis database. Requires a separate Redis server.
WebdisStore: Uses a Webdis endpoint to store session data. This is ideal for serverless environments, or anywhere that only HTTP endpoints can be accessed (such as Deno Deploy). Requires a Webdis URL.

Usage

To use Session, you need to first add in Session as middleware. Once added, you can get and set variables for the session using the get and set functions on the session variable created. Below are examples of adding and using Session with various frameworks:

Oak

import { Application, Router } from "https://deno.land/x/oak/mod.ts";
import { OakSession } from "https://deno.land/x/sessions/mod.ts";

const app = new Application();

// Attach sessions to middleware
const session = new OakSession(app);

const router = new Router();

router.get("/", async (context) => {

    // Examples of getting and setting variables on a session
    if (await context.state.session.get("pageCount") === undefined) {
        await context.state.session.set("pageCount", 0);

    } else {
        await context.state.session.set("pageCount", await context.state.session.get("pageCount") + 1);
    }
    
    context.response.body = `Visited page ${await context.state.session.get("pageCount")} times`;
});

app.use(router.routes());
app.use(router.allowedMethods());

await app.listen({ port: 8000 });

Opine (with Redis storage)

import { opine } from "https://deno.land/x/opine/mod.ts";
import { OpineSession, RedisStore } from '../session-2/mod.ts'

const app = new opine()
const store = new RedisStore({
  host: '0.0.0.0',
  port: 6379
})

await store.init()

const session = new OpineSession(app, {}, store)

app.use("/", async (req, res) => {
  // Examples of getting and setting variables on a session
  if (await req.session.get("pageCount") !== undefined) {
    await req.session.set("pageCount", await req.session.get("pageCount") + 1);
  } else {
    await req.session.set("pageCount", 0);
  }

  res.setStatus(200).send(`Visited page ${await req.session.get("pageCount")} times`)
});

app.listen(8002, () => console.log("Server at http://localhost:8080"));

Storage

By default, MemoryStorage is the storage driver, but you can (and should in production) use a more robust and persistent storage driver. Here are some options:

SQLite

import { Application, Router } from "https://deno.land/x/oak/mod.ts";
import { OakSession, SqliteStore } from "https://deno.land/x/sessions/mod.ts";

const app = new Application();
const store = new SqliteStore({
    path: './database.db',
    tableName: 'sessions' // optional
})

// Attach sessions to middleware
const session = new OakSession(app, store);

// ...

Redis

import { Application, Router } from "https://deno.land/x/oak/mod.ts";
import { OakSession, RedisStore } from "https://deno.land/x/sessions/mod.ts";

const app = new Application();
const store = new RedisStore({
    host: '127.0.0.1',
    port: 6379
});

// Since Redis connection is async, must be initialized before used
await store.init();

// Attach sessions to middleware
const session = new OakSession(app, store);

// ...

Webdis

import { Application, Router } from "https://deno.land/x/oak/mod.ts";
import { OakSession, WebdisStore } from "https://deno.land/x/sessions/mod.ts";

const app = new Application();
const store = new WebdisStore({
    url: 'http://127.0.0.1:7379',
});

// Attach sessions to middleware
const session = new OakSession(app, store);

// ...

More stores will be added over time.