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

License

MIT