The go-middleware's intro from fakundo

go-middleware's Introduction

go-middleware

Middleware for Go functions.

Works perfectly with socket.io event handlers – https://github.com/googollee/go-socket.io

Installation

go get github.com/fakundo/go-middleware

Usage

Create middleware

import (
  middleware "github.com/fakundo/go-middleware"
  socketio "github.com/googollee/go-socket.io"
)

var requireAuth = middleware.Create(func(s socketio.Conn, next func()) {
  if authorized(s) {
    next()
  } else {
    s.emit("error", AuthError)
  }
})

Use it

import socketio "github.com/googollee/go-socket.io"

io, _ = socketio.NewServer(nil)

io.OnEvent("/", "some-event", requireAuth(func(s socketio.Conn) {
  // some event handler code
}))


io.OnEvent("/", "another-event", requireAuth(func(s socketio.Conn, arg string) {
  // another event handler code
}))

Middleware composition

import middleware "github.com/fakundo/go-middleware"

...

io.OnEvent("/", "event", middleware.Use(someMiddleware, requireAuth, func(s socketio.Conn) {
  // event handler code
}))

About middleware behaviour

currently the decorated function type must be interface (exactly like socket.io event handlers)
the origin function and middleware can have different number of arguments, middleware will only take required arguments, and the last argument is always next
next() calls the origin function
the origin function may return something, so next() will return that too