# MiddlewareHandler
[](https://travis-ci.org/nkzawa/middleware-handler)
MiddlewareHandler manages custom middlewares in the same way as how Express/Connect does.
```js
var MiddlewareHandler = require('middleware-handler');
var handler = new MiddlewareHandler();
handler.use(function(a, b, next) {
console.log(a, b); // foo bar
next();
});
handler.handle(['foo', 'bar']);
```
## Installation
$ npm install middleware-handler
## Example
### Integration with Socket.io
Parsing cookie from handshake's data with the authorization.
```js
var cookieParser = require('express').cookieParser('secret');
var handler = new MiddlewareHandler();
handler.use(function(handshakeData, next) {
// handshakeData has almost the same attributes with request object.
cookieParser(handshakeData, {}, next);
});
var io = require('socket.io').listen(8080);
io.set('authorization', function(handshakeData, callback) {
handler.handle([handshakeData], function(err) {
console.log(handshakeData.cookies);
callback(err, !err);
});
});
```
## Documentation
### #use(middleware)
```middleware``` accepts variable arguments and a callback.
```js
var handler = new MiddlewareHandler();
handler.use(function(arg, next) {
var err;
// do some stuff
next(err); // optionally accepts an error object
});
```
```js
handler.use(function(arg, next) {
next(null, 'foo'); // arguments will be passed to a next middleware
});
handler.use(function(arg, next) {
console.log(arg); // 'foo'
next();
});
```
### #handle([args], [callback])
Invokes middlewares.
```js
var handler = new MiddlewareHandler();
handler.use(function(a, b, next) {
console.log(a, b); // 'foo bar'
next();
});
handler.handle(['foo', 'bar'], function(err) {
// after calling all middlewares
});
```
### #compose([callback])
Creates a function which invokes middlewares.
```js
var handler = new MiddlewareHandler();
handler.use(function(a, b, next) {
console.log(a, b); // 'foo bar'
next();
});
var fn = handler.compose(function(err) {
// after calling all middlewares
});
fn('foo', 'bar');
```
### #clear()
Clear all middlewares from the stack.
```js
var handler = new MiddlewareHandler();
handler.use(function() {});
console.log(handler.stack.length); // 1
handler.clear();
console.log(handler.stack.length); // 0
```
### compose(middlewares...)
Creates a function which invokes the passed middlewares.
```js
function middleware(a, b, next) {
console.log(a, b); // 'foo bar'
next();
}
var fn = MiddlewareHandler.compose(middleware, function(a, b) {
console.log(a, b); // 'foo bar'
});
fn('foo', 'bar');
```
## License
MIT
