midware

midware is a tiny module to create domain-agnostic middleware layers for any node.js or browser application. Inspired in the middleware pattern by connect.

It's just ~80 SLOC.

Example

var use = require('midware')()
var message = {}

use(function(msg, next) {
  // msg === message
  next()
})

use.run(message, function(err) {
  if (err) return console.log(err)
  // finished
})

Installation

Node.js

npm install midware

Browser

Via bower:

bower install midware

Via component:

component install h2non/midware

Loading the script:

<script src="//cdn.rawgit.com/h2non/midware/0.1.7/midware.js"></script>

Test

To run tests use npm.

$ npm install
$ npm test

Documentation

Basic Usage

Middleware is useful for creating a plugin system or configuring anything within an application. To use midware just require it and make a call to the module.

var midware = require('midware')
var use = midware()

This will return a use function which when passed a callback will add it a waterfall sequence that will be invoked one after the other whenever the middleware is run.

use(function(next) {
  // mad science here
  next()
})

Callbacks are given a next function which will always be the last argument. Calling next will tell the middleware to call the next callback in the use sequence or will complete its run. To run the callback sequence call the method run on the use function.

use.run(function(err) {
  if (err) { return console.log(err) }
  // all done professor
})

run takes any amount of parameters that the callbacks will passed whenever run.

use(function(first, last, next) {
  console.log('Hello %s, %s', first, last)
  next()
})
use.run('Christopher', 'Turner')

Stopping

Whenever a callback should throw an exception or wish to stop the middleware from running any more calls. Give next an error or explicitly tell it stop.

use(function(next) {
  next(new Error()) // stops middleware and gives error
  next(null, true) // tells middleware to stop
})

use.run(function (err, ended) {
  // ...
})

Apply Context

Instead of binding context to callbacks, send the context to midware.

var context = {}
var use = midware(context)
use(function(next) {
  // this === context
  next()
})
use.run(function(err) {
  // this === context
})

Removing a function

You can remove registered functions in the middleware via its function name or function reference

var use = midware()
use(function test(next) {
  next()
})
use.remove('test') // by function name

var use = midware()
function test(next) {
  next()
}
use(test)
use.remove(test) // by function reference

API

midware([context])

use(callback...)

use.remove(name|function)

use.run([args...], [done])

use.flush()

use.stack = [ function... ]

License

MIT

Copyright (c) 2014 Christopher Turner Copyright (c) 2015 Tomas Aparicio