grapnel-server/README.md

Node.js Router Framework with Named Parameter & Middleware support

Grapnel Server-Side Router Framework for Node.js
==========

#### Simple JavaScript Router for Node.js with Named Parameters and Middleware support.

## Download/Installation

**Install with npm**
```bash
npm install grapnel-server
```

# Grapnel Features

- Supports Named Parameters similar to Sinatra, Restify, and Express
- Middleware Support
- RegExp Support
- No dependencies

## Server-Side Routing

```javascript
var http = require('http'),
    app = require('grapnel-server');

app.get('/products/:category/:id?', function(req, res, next){
    var id = req.params.id,
        category = req.params.category

    console.log(category, id);

    res.end('Hello World!', 200);
});

http.createServer(app.start()).listen(3000);
```

## Named Parameters

Grapnel.js supports regex style routes similar to Sinatra, Restify, and Express. The properties are mapped to the parameters in the request.
```javascript
app.get('products/:id?', function(req, res){
    // GET /products/134
    req.params.id
    // => 134
});

app.get('products/*', function(req, res){
    // The wildcard/asterisk will match anything after that point in the URL
    // Parameters are provided req.params using req.params[n], where n is the nth capture
});
```

## Middleware Support

Grapnel.js also supports middleware:

```javascript
var auth = function(req, res, next){
    user.auth(function(err){
        req.user = this;
        next();
    });
}

app.get('/*', auth, function(req, res){
    console.log(req.user);
    res.end('Hello ' + req.user.name, 200);
});
```

## Route Context

You can add context to a route and even use it with middleware:

```javascript
var usersRoute = router.context('/user/:id', getUser, getFollowers); // Middleware can be used here

usersRoute.get('/', function(req, res, next){
    console.log('Profile', req.params.id);
});

usersRoute.get('/followers', otherMiddleware, function(req, res, next){ // Middleware can be used here too
    console.log('Followers', req.params.id);
});

usersRoute.post('/', function(req, res, next){ // Middleware can be used here too
    console.log('POSTED to /user/:id', req.params.id);
});

// GET /user/13589
// => Profile 13589

// GET /user/13589/followers
// => Followers 13589

// POST /user/13589
// => POSTED to 13589
```


## Declaring Multiple Routes

```javascript
var Grapnel = require('grapnel-server').Server;

var routes = {
    'products' : function(req, res, next){
        // GET /products
    },
    'products/:category/:id?' : function(req, res, next){
        // GET /products/widgets/35
        req.params.category
        // => widgets
    }
}

Grapnel.listen(routes);
```

## Event Handling

```javascript
var app = require('grapnel-server');

app.on('navigate', function(){
    // GET /foo/bar
    console.log('URL changed to %s', this.path());
    // => URL changed to /foo/bar
});
```

## RegExp Support

Grapnel.js allows RegEx when defining a route:

```javascript
var expression = /^\/food\/tacos\/(.*)$/i;

app.get(expression, function(req, res){
    // GET /food/tacos/good
    console.log('I think tacos are %s.', req.params[0]);
    // => "He thinks tacos are good."
});
```

 

***

# Usage & Tips

## Middleware
Grapnel uses middleware similar to how Express uses middleware. Middleware has access to the `req` object, `event` object, and the next middleware in the call stack (commonly denoted as `next`). Middleware must call `next()` to pass control to the next middleware, otherwise the router will stop.

For more information about how middleware works, see [Using Middleware](http://expressjs.com/guide/using-middleware.html).
```javascript
var user = function(req, res, next){
    user.get(function(err){
        req.user = this;
        next();
    });
}

app.get('/user/*', user, function(req, res){
    console.log(req.user);
    res.send(req.user.name);
});
```

## Stopping a Route Event
```javascript
app.on('match', function(req){
    req.event.preventDefault(); // Stops event handler
});
```

## Stopping Event Propagation
```javascript
app.get('/products/:id', function(req, res){
    req.event.stopPropagation(); // Stops propagation of the event
});

app.get('/products/widgets', function(req, res){
    // This will not be executed
});

// GET /products/35
```

## 404 Pages
You can specify a route that only uses a wildcard `*` as your **final route**, then use `req.event.parent()` which returns `false` if the call stack didn't run any route handlers.
```javascript
// This should be your last route
app.all('*', function(req, res){
    if(!this.state.parent()){
        res.writeHead(404);
        res.end('404');
    }
});
```

 

***

# API Documentation

##### `get`, `post`, `put`, `delete` (HTTP Method) Adds a listeners and middleware for routes matching its respective HTTP method
```javascript
/**
 * @param {String|RegExp} path
 * @param {Function} [[middleware], callback]
*/
app.get('/store/:category/:id?', function(req, res){
    var category = req.params.category,
        id = req.params.id;

    console.log('Product #%s in %s', id, category);
});

app.post('/store/:category', function(req, res){
    var category = req.params.category;

    console.log('POST Product %s', category);
});

app.put('/store/:category', function(req, res){
    var category = req.params.category,
        id = req.params.id;

    console.log('PUT Product #%s in %s', id, category);
});

app.delete('/store/:category/:id', function(req, res){
    var category = req.params.category,
        id = req.params.id;

    console.log('DELETE Product #%s in %s', id, category);
});

app.all('/store/', function(req, res){
    // This will be called with any HTTP method
});
```

##### `on` Adds a new event listener
```javascript
/**
 * @param {String} event name (multiple events can be called when separated by a space " ")
 * @param {Function} callback
*/
router.on('myevent', function(event){
    console.log('Grapnel.js works!');
});
```

##### `once` A version of `on` except its handler will only be called once
```javascript
/**
 * @param {String} event name (multiple events can be called when separated by a space " ")
 * @param {Function} callback
*/
router.once('init', function(){
    console.log('This will only be executed once');
});
```

##### `trigger` Triggers an event
```javascript
/**
 * @param {String} event name
 * @param {Mixed} [attributes] Parameters that will be applied to event handler
*/
app.trigger('event', eventArg1, eventArg2, etc);
```

##### `context` Returns a function that can be called with a specific route in context.
Both the `router.context` method and the function it returns can accept middleware. Additionally, you can specify which HTTP method (GET, POST, PUT, DELETE) should be routed by the callback. Not specifying an HTTP method will assume GET.

**Note: when calling `route.context`, you should omit the trailing slash.**
```javascript
/**
 * @param {String} Route context (without trailing slash)
 * @param {[Function]} Middleware (optional)
 * @return {Function} Adds route to context
*/
var usersRoute = router.context('/user/:id');

usersRoute.post('/', function(req, res, next){
    console.log('POSTED to', req.params.id);
});

// Not specifying an HTTP method assumes GET
usersRoute('/followers', function(req, res, next){
    console.log('Followers', req.params.id);
});

// GET /user/13589/followers
// => Followers 13589

// POST /user/13589
// => Followers 13589
```

##### `bind` An alias of `on`
##### `add` An alias of `get`
##### `path`
* `router.path('string')` Sets a new path or hash
* `router.path()` Gets path or hash
* `router.path(false)` Clears the path or hash

##### `fragment` (Deprecated)

## Events
* `navigate` Fires when http module initializes a new request
* `match` Fires when a new match is found, but before the handler is called

## License
##### [MIT License](http://opensource.org/licenses/MIT)