hapi-io

A Primus integration with hapi (inspired by express.oi and express.io).

Table of Contents

• Installation and Configuration
• Authorization
• Raw access to Primus
• Forward primus events to hapi routes

Installation and Configuration

npm install hapi-io --save

server.register({
  register: require('hapi-io'),
  options: {
    ...
  }
});

Options

• connectionLabel - an optional label to select the connection on which to
• primus - an object which is passed through to Primus.
• auth - authentication configuration for the socket handshake. Value can be any route auth configuration understood by hapi.

Authorization

hapi-io can use a hapi auth strategy to authorize a socket.io connection. The socket.io client will not be able to connect if it fails the authentication check.

See options for how to configure.

Raw access to Primus

You can get raw access to the Primus instance as follows:

exports.register = function(server, options, next) {

  var primus = server.plugins['hapi-io'].primus;

};

Forward events to hapi routes

Perfect for exposing HTTP API endpoints over websockets!

Primus events can be mapped to hapi routes; reusing the same authentication, validation, plugins and handler logic.

Example

Server

exports.register = function(server, options, next) {

  server.route([

    {
      method: 'GET',
      path: '/users/{id}',
      config: {
        plugins: {
          'hapi-io': 'get-user'
        }
      },
      handler: function(request, reply) {
        db.users.get(request.params.id, function(err, user) {
          reply(err, user);
        });
      }
    },

    {
      method: 'POST',
      path: '/users',
      config: {
        plugins: {
          'hapi-io': {
            event: 'create-user',
            mapping: {
              headers: ['accept'],
              query: ['returnType']
            }
          }
        }
      },
      handler: function(request, reply) {
        db.users.create(request.payload, function(err, user) {
          if (err) {
            return reply(err).code(201);
          }

          if (request.headers.accept === 'application/hal+json') {
            addMeta(user);
          }

          if (request.query.returnType !== 'full') {
            user = _.omit(user, 'favoriteColor');
          }

          reply(err, user);
        });
      }
    }

  ]);
};

Client

var socket = io();

socket.emit('get-user', { id: 'sibartlett'}, function(res) {
  // res is the result from the hapi route
});

socket.emit('create-user', {
  name: 'Bill Smith',
  email: 'blsmith@smithswidgets.com',
  location: 'remote',
  favoriteColor: 'green',
  returnType: 'full'
}, function (res) {
  // do something with new user
});

How it works

Each time an event is received, a fake HTTP request is created and injected into the hapi server.

The fake HTTP request is constructed as follows:

1. The headers and querystring parameters from the socket.io handshake are added to the fake request.

This allows you to use the route's auth stategy - to authenticate the socket.io event.

2. Each field in the event payload is mapped to one of the following hapi param types: headers, path, query or payload. The mapping is determined on a per field basis:

3. If the field is a parameter in the route's path, it's mapped as a path parameter.

4. If the hapi-io config is an object and has a mapping property, then the field is checked against the mapping. Allowed mappings are headers, query, and payload.

5. If the field exists in the route's validate object, the value is mapped to the corresponding param type.

6. If the route is a 'GET' method, the field is mapped as a query param.

7. Otherwise it's mapped as a payload field.

8. Maps "Authorization" attribute from query or data object if possible and not already mapped.

Post event hook

You can do further processing on a Primus event, after it has been processed by hapi.

You can use the post option to specify a function, with two parameters: ctx and next. ctx has the following properties:

• primus - the Primus instance
• spark - the Primus spark instance
• event - the Primus event
• data - the event's data object
• req - the request object that was injected into hapi
• res - the result object that was returned by hapi
• result - the res.result

server.route({
  method: 'POST',
  path: '/rooms/{roomId}/join',
  config: {
    plugins: {
      'hapi-io': {
        event: 'join-room',
        post: function(ctx, next) {
          ctx.spark.join(ctx.data.roomId);
          next();
        }
      }
    }
  },
  ...
});