primus-route-handler

Declare your API via express router and communicate with it via Primus.io or Primus+primus-emitter (required for ack-callbacks) websocket.

API

This module exports single function

var ws_api_handler = require('primus-route-handler');

which returns a callback for your api requests:

spark.on('api', ws_api_handler(spark, router));

You can use anything else instead of 'api' here, but make sure that client uses the same channel.

Example

Server:

// sample routes
var router = require('express').Router();
router.use(checkAuth);
router.get('/user/:id', function (req, res) {
    ... get user info from database ...
    res.send(userinfo);
});
 
...
var ws_api_handler = require('primus-route-handler');
 
primus.on('connection', function (spark) {
    spark.on('api', ws_api_handler(spark, router));
});

Client:

var socket = new Primus('http://localhost:3000');
// This triggers GET /user/:id route defined above:
socket.send('api', '/user/1234', function (err, userinfo) {
    if (err) {
        // handle error
        // err.status contains status code
        // err.statusText may contain further description
    }
    console.log('User info:', userinfo);
});

Simple way to specify path and optionally method is to use string argument of the form METHOD::PATH

socket.send('api', 'POST::/user', {name: 'john', age: 30}, cb);

Alternatively one can pass an object with fields path (/ by default), meth (get), headers ({content-type: 'application/json'}), query (if this field is not provided the query will be extracted from path and parsed):

socket.send('api', {meth: 'post', path: '/user'}, {name: 'john', age: 30}, cb);

Method defaults to 'get'.

Routes

You specify routes as usually with express 4 router (router module should work too.) In route callbacks req argument can be used to gather information about request and res allows to send response and set status. The same router may be usually mounted into your express app to handle AJAX requests.

req

Available standard express fields are: req.url, req.query (parsed with qs), req.body, req.method, req.headers={'content-type': 'application/json'} (default). Additionally req.spark is available in case you want to do something specific and do not plan to use this route for ajax. You can get original request object via req.spark.request.

res

To send client response use res.send(data). To set status use res.status(code [, description]).send(). res.send, res.end, res.json are all the same function.

Client library

Browserify users may require this module in client code to obtain simple api wrapper with standard methods get, post, put, delete and patch:

var socket = new Primus();
var api = require('primus-route-handler')(socket);
api.post('/user', {name: 'Vasja', age: 50}, function (err, res) {...});

Final handler

• If there are no matching route or last route handler calls next() an error {status: 404, statusText: 'Not Found'} is sent to client.
• If middleware calls next(ErrorObject) then error {status: ErrorObject.status || 500, statusText: ErrorObject.text || ErrorObject+''} is returned to client.
• If next(ErrorCode) is used then {status: ErrorCode, statusText: ErrorCode+''} is sent.

restify

You can generate REST routes for your Mongoose models using express-restify-mongoose:

var router = express.Router();
var restify = require('express-restify-mongoose');
restify.serve(router, SomeMongooseModel);

Resulting router can be used to provide access to SomeMongooseModel over HTTP:

app.use(router);

as well as to provide the same routes over websocket:

primus.on('connection', function (spark) {
    spark.on('api', ws_api_handler(spark, router));
});

Other modules working with express.Router() should work with primus-route-handler too (with minor tweaks maybe). This is actually the whole point of this module -- to re-use existing code as much as possible.

License

MIT