Hall

Unified HTTP middleware router. It works with express, connect and native http server. It's goal is provide routring for distributable and modular web applications and support standard behavior.

Installation

npm install hall

Usage

Example of middleware factory.

const hall = require('hall');
const connect = require('connect');

// Middleware factory
connect()
    .use(hall((router) => {
        router.get('/products/:id', (req, res) => {
            // ...
        });
    });

Example of router factory.

const hall = require('hall');
const connect = require('connect');

// Router instance
const router = hall();

router.resource('/products/:id')
.get((req, res, next) => {
    // Return product...
})
.put((req, res, next) => {
    // Update product...
})
.delete((req, res, next) => {
    // Delete product...
});


router.get('/products/:id/reviews', (req, res) => {
    // ...
});

connect().use(router);

Resources are differs from single routes. It processing before routes. If resource exists but method not defined than response gets 405 status code (method not allowed).

API

router.resource(route: string[, handlers: Object]) => Resource

Add resource. If route is defined return existing resource instance. If handlers is an object use property names as methods names and values as a handlers:

router.resource('/users/:id')
.get((req, res, next) => {
    // ...
})
.put((req, res, next) => {
    // ...
});

router.resource('/docs/:id', {
    get(req, res, next) {
        // get...
    },
    delete(req, res, next) {
        // delete...
    }
});

Methods

Router has methods before, after, filter and use. This methods allow to control process of request preprocessing and filtering. Note that before and after handlers will not be called if there is no matching routes.

var router = hall();

// Preprocess request
router.before((req, res, next) => {
    req.version = req.headers['X-API-VERSION'];
    next();
});

// Pass only 2.0 API requests.
router.filter((req) => {
    return req.version === '2.0'
});

router.after((error, req, res, next) => {
    // Got an error or nothing is found...
});

router.get('/product/:id', (req, res, next) => {
    // Get and render product
    res.end();
});

HTTP Methods

Methods to bind http methods routes. There is several supported HTTP methods:

• GET
• POST
• PUT
• DELETE
• PATCH
• HEAD

Each HTTP-method has it's own lowercased alias:

router.get('/', (req, res, next) => {
  // ...
});

router.post('/', (req, res, next) => {
  // ...
});

router.patch('/', (req, res, next) => {
  // ...
});

Also route could be instance of hall.RouteParser:

router.get(new hall.RouteParser('/some/:id'), (req, res, next) => {
  // ...
});

Filter

Filter method allow to filter requests in smarter way. It's using for dynamic request filtering. Filter method should return boolean, promise or use methods;

// Boolean
router.filter((req) => {
    return req.hostname === 'localhost';
});

// Promise
router.filter((req) => {
    return new Promise((resolve, reject) => {
        // Do some async job
    });
});

// Methods
router.filter((req, next, skip) => {
    if (req.hostname === 'localhost') {
        next();
    } else {
        skip();
    }
});

Use

Method use is context dependent and it will call before if there is no routes defined and after in other way.

router.use((req, res, next) => {
    // Call before
    next();
});

router.get('/product/:id', (req, res, next) => {
    // Get and render product
    res.end();
});

router.use((req, res, next) => {
    // Call after
    next();

Workflow

Router will not call any method if request has no matching url. This is made for request isolation and high productivity. If you have some job which should be done for each request move it to previous loop.