Middlewares in @xiara/web

@ Xiara/web middlewares + rest api boilerplate

About the project

Xiara is a framework for building efficient, scalable Node.js server-side applications. It uses modern JavaScript, is built with TypeScript (preserves compatibility with pure JavaScript) and combines elements of OOP (Object Oriented Programming), FP (Functional Programming), and FRP (Functional Reactive Programming).

Under the hood, Xiara makes use of Express, allowing for easy use of the third-party plugins.

Xiara also features mongodb support out of the box via @xiara/mongo package

What Changed?

I have been continuing adding new features, providing examples and extending the functionalities of the framework, heres a short summary:

@ xiara/web:

Added middleware support
Improved policy handling & definitions
Cleaned up unused packages and code
Pushed updated packages to npm

@ xiara/mongo:

Fixed a bug regarding when referencing collections won't populate the required fields on query.
Pushed a new update on npm

@ xiara/boilerplate

Updated the boilerplate and added more examples with a fully working rest-api example

Middlewares

So middlewares, what they do? How to use them? First lets look at how to make one.

import { Middleware, IMiddleware, WebServer } from "@xiara/web";

// Define the middleware to be used on all path starting with /private
@Middleware({ path: "/private" })
export class UserMiddleware implements IMiddleware
{
    constructor(public my: MyService)
    {
    }

    OnRegister(app: WebServer)
    {
      // register custom handler or do stuff with the express app
    }
    
    // Or use the default middleware handler function
    handler(req, res, next)
    {
        req.user = await Users.findOne({ authToken: req.params.authToken });
        next(); // Next is mandatory!
    }
}

The constructor as usual can be used for Dependency Injection :)

The decorator @Middleware is used to populate metadata and tell the application how and when to use this middleware. The callback OnRegister can be used to bind methods or further events to the middleware. For example cors, express bodyParser are a great example.

OnRegister(app: WebServer)
{
    app.use(cors());
}

The handler is the core function of the middleware, it can be used to populate the request object with additional parameters as shown in the example it adds a user field to the request object that can be later used in the application:

handler(req, res, next)
{
    req.user = await Users.findOne({ authToken: req.params.authToken });
    next(); // Next is mandatory!
}

All we have left is to add it to our app module.

import { WebModule } from "@xiara/web";
import { UserMiddleware } from "./UserMiddleware";
@WebModule({
    middlewares: [
        UserMiddleware,
    ]
})
export class AppModule
{
}

And that would be it, the rest of the magic is all handled by xiara here!

Relevant commits:

The project is split into multiple repositories as i am trying to create reusable packages and it's also easier to manage updates for me. I've also created an organization to easier keep track of this project.

Roadmap

My vision on the project is that theres still a long way to go to implement all the funcitonalities a modern backend framework would require. But even then i am pretty happy with the progress and the framework turns out to be very useful in my projects.

For the next weeks i put the following on the road-map:

Add more functionalities to the MongoDB ODM
Input validators
Inject decorator
Injector options add more options to change behavior how injectables get injected
Async resolve for injectables
AppServices & Predefined Services to alter application behavior
A CLI tool to quickly genreate controllers, policies, middlewares, components
Tests
A Quick Start Guide, Tutorials, Examples and an API Reference / Documentation