@aldojs/application

A generic application which uses internally a service container and a middleware dispatcher to handle any context object.

import { createApplication } from '@aldojs/application'

let app = createApplication()

// add a sum handler
app.use(({ a, b }) => a + b)

// handle the context
let result = app.handle({ a: 1, b: -1 })

Middlewares

Middlewares could be a common or an async function. please refer to @aldojs/middleware for more information on how middlewares are dispatched.

// Handler function signature
declare type Middleware = (ctx: Context, next: () => any) => any;

You can register as many middlewares as needed with the application's method .use(fn).

// to add a handler directly in the stack
app.use(middleware)

Context

The context is a plain object, containing all data needed by the middlewares to do their job. A proxied version is passed to the middleware chain, instead of the original context object, to provide the same fields, in addition to the properties defined with .set(key, value) or .bind(key, factory) methods. In other, you can access the services registered within the application, directly in the middlewares

declare interface Context {
  [key: string]: any;
}

You may use Application::set(key, instance) to share instances between contexts, like a DB connection or a global logger.

import Mongoose from 'mongoose'

// set up the mongon db connection
// let connection = ...

// register it within the context
app.set('db', connection)

You may also use .bind(key, fn) to bind per-context instances. This method takes the field name, and the factory function to create the service object on demand.

let options = {/* some session options */}

// a new instance of Session is `lazily` created for each context
app.bind('session', () => new Session(options))

.has(key) and .get(key) are aldo available to check the existence of a certain service or to get a previously defined one.