mw

This is a collection of useful middlewares.

redirect

node middleware that handles redirection.

Usage

{redirect} = require 'middleware'
 
# redirects `/foo` to `/bar` 
router.get '/foo',
    redirect '/bar'
 
# redirects `/foo/$var` to `/bar/$var` 
router.get '/foo/:id',
    redirect (req) -> "/bar/#{req.params.id}"

render

middleware to render arbitrary views. This middleware can be used with all existing template engines.

Usage

Middleware called before render should populate the req.loaded object with data that the view should present to the client render will send the output of view req.loaded to the client

Example

jsonView = (params) -> JSON.stringify params
 
router.get '/resource',
    (req, res, next) ->
        req.loaded =
            foo: 'bar'
            fitz: [1..10]
        next()
    render jsonView
 
# will render `'{"foo":"bar","fitz":[1,2,3,4,5,6,7,8,9,10]}'` to the 
# client 

bind

Transforms an asynchronous function into a middleware. The result of the function will be bound to request.loaded.

Use this library if you want to load async data in a clean way.

Short Description

Transforms an asynchronous function f into a middleware. The middleware will call f with (req, callback). f has to call callback with err, value which will cause value to be bound to req.loaded[name].

Usage

bind name, (req, next) ->
    # do async stuff and call `next` when you are finished 
    error = null
    result = 'result'
    next error, result

name is the directive where to save the results from function.

# will bind the result of asnycMethod to `req.loaded.foo` 
bind 'foo', (req, next) -> asyncMethod next

name can be nested.

# will bind the result of asyncMethod to `req.loaded.foo.bar` 
bind 'foo.bar', (req, next) -> asyncMethod next

If the asynchronous method returns an error the process is aborted and a Status Code of 500 is returned to the user.

Example

router.get '/user',
    bind 'users.all', (req, next) -> dao.user.all next
    (req, res, next) -> next console.log 'loaded users', req.loaded.users.all
    # will output the result of `dao.user.all` 
    render view.user.all
 
router.get '/user/:id',
    bind 'user.object', (req, next) -> dao.user.byId req.params.id, next
    render view.user.show

exec

Simple way to create middleware that should not modify the response. Takes care of errors. Useful for tasks like updating the database.

Example

router.post '/user/:id',
    exec (req, next) -> dao.user.update req.params.id, req.body, next

Without exec

router.post '/user/:id',
    dao.user.update req.params.id, req.body, (err) ->
        if err?
            res.writeHead 500
            res.end 'Internal Server Error'
        else
            next()

flash

used for setting, loading flash messages.

 
{loadFlash, flash, redirect, render} = require 'mw'
 
router.post '/foo',
    flash 'hello flash'
    redirect 'back'
 
router.get '/foo'
    loadFlash
    (req, res, next) -> next console.log req.loaded.flash
    # prints {message: 'hello flash', type: 'info' 
    # view.foo will receive `req.loaded` and can print them to the dom 
    render view.foo
 

A view helper for displaying alerts can be found in dombox.

condition

if-else statement as a middleware

 
{condition} = require 'mw'
 
# the condition is dependant on the state 
# in this example we use this simplified conditions 
alwaysTrue = (req) -> true
alwaysFalse = (req) -> false
 
# this would be a useful condition 
isLoggedIn = (req) -> req.session?.user?
 
log = (msg) -> (req, res, next) -> next console.log msg
 
 
# for details about sequenz see https://github.com/snd/sequenz 
http.createServer sequenz [
    condition alwaysTrue log('this middleware is executed'), log('this middleware is ignored')
    condition alwaysFalse log('this middleware is ignored'), log('this middleware is executed')
    condition alwaysFalse log('nothing is shown and the next middleware is executed')
    (req, res, next) -> req.end()
]

Parse Basic Auth

Allows to parse Basic Auth received from the Authorization Header.

http.createServer sequenz [
    mw.parseBasicAuth()
    (req, res, next) ->
        console.log "Credentials are User: #{req.credentials?.user} Password: #{req.credentials?.password}"
        req.end()

Allows to set a default value if no credentials are submitted

mw.parseBasicAuth {user: '', password: ''}