HAPI

jaxnode july 2014

Code on the Beach August

RobotsCONF December

Hapi HAPI, joi joi

http://youtu.be/y0V4TZAyd8I

hapi.js

Hapi short for HTTP API, or so they say

Developed by Walmart Labs

Eran Hammer also authored OAuth

Developed as a proxy for Mobile Services

walmart really?

Walmart is very high tech

Invented EDI

Replacing legacy AS400 and Java services with Node.js

NPM rewritten from scratch with Hapi

req, res, next

Express, Connect and Director follow pattern

Middleware Hell

Modules needed for all features you need

Express to be replaced by Koa

Koa requires ES6

Hapi.js

Hapi full framework for Rest and Web

Open Source

@ Version 6

Routes

Caching

Sessions

Logging

Authentication

Plugins

100% code coverage

Configuration over code

You can configure with code

Configurations can be stored in json and loaded at runtime

http Object Abstraction

Request and Response Object can change

HTTP objects have changed with versions of Node

They have changed with Express

Express gives you raw request objects

Hapi provides those objects if you need them

Three R's of hapi

Reflection - Code stubing and documentation

Reduce Errors - Validation and Route handling

Reusability - business logic, helpers, caching

Plugins

Hapi framework will slowly add features into Hapi, and then extract out plugins if warranted

Joi validation is plugin

Swagger, Lout plugin for Documentation

var Hapi = require('hapi');

            // Create a server with a host and port
            var server = new Hapi.Server('localhost', 8000);

            // Add the route
            server.route({
                method: 'GET',
                path: '/hello',
                handler: function (request, reply) {

                    reply('hello world');
                }
            });

            // Start the server
            server.start();

var Hapi = require('hapi');
            var server = new Hapi.Server(3000);

            server.route({
                method: 'GET',
                path: '/',
                handler: function (request, reply) {
                    reply('Hello, world!');
                }
            });

            server.route({
                method: 'GET',
                path: '/{name}',
                handler: function (request, reply) {
                    reply('Hello, ' + encodeURIComponent(request.params.name) + '!');
                }
            });

            server.start(function () {
                console.log('Server running at:', server.info.uri);
            });

handler

2.0 adding breaking change

fn(request, reply);

function myHandler(request, reply) {
            reply(msg + "Hello, World");
            }

request contains raw references to both the request and response objects

using plugins

var Good = require('good');

            server.pack.register(Good, function (err) {
                if (err) {
                    throw err; // something bad happened loading the plugin
                }

                server.start(function () {
                    server.log('info', 'Server running at: ' + server.info.uri);
                });
            });

Plugins are really used to modularize your app

Catalog and Cart could be two different plugins

Routes

server.route({
                method: 'GET',
                path: '/',
                handler: someHandler
            });

            server.tables();

packs

Packs are a way for Hapi to combine multiple servers into a single unit, and are designed to give a unified interface when working with plugins.

You can assign labels to each server.

You can have 'PublicWeb', 'Api' and 'Admin' as separate packs.

plugins

exports.register = function (plugin, options, next) {
                next();
            };

            exports.register.attributes = {
                pkg: require('./package.json')
            };

var myPlugin = {
                register: function (plugin, options, next) {
                    next();
                }
            }

            myPlugin.register.attributes = {
                name: 'myPlugin',
                version: '1.0.0'
            };

validation

Hapi uses Joi validation

Failed validation returns 400 status code

server.route({
                method: 'GET',
                path: '/hello/{name}',
                handler: function (request, reply) {
                    reply('Hello ' + request.params.name + '!');
                },
                config: {
                    validate: {
                        params: {
                            name: Joi.string().min(3).max(10)
                        }
                    }
                }
            });

HELPERS, er I mean server methods

var add = function (a, b, next) {

                next(null, a + b);
            };

            server.method(
            { name: 'sum', fn: add, options: { cache: { expiresIn: 2000 } } });

            server.methods.sum(4, 5, function (err, result) {
                console.log(result);
            });

CACHing

Uses the Catbox module

Support for in memory cache up to 100MB

Support for scalable cache through Redis, MongoDB, Memcached, and Riak

cache: {
                expiresIn: 60 * 1000,
                staleIn: 45 * 1000,
                staleTimeout: 500
            }

Routing config options

Can specify handlers

Set up endpoint cache

You can also setup Route prerequisites for handling asynchronous and synchronous processing before replying to an http request

server.route({
                method: 'GET',
                path: '/hello/{name}',
                config: {
                    handler: function (request, reply) {
                        reply('Hello ' + request.params.name + '!');
                },
                validate: {
                    params: {
                        name: Joi.string().min(3).max(10)
                    }
                }
                }
            });

var pre1 = function (request, reply) {
                reply('Hello');
            };
            var pre2 = function (request, reply) {
                reply('World');
            };
            var pre3 = function (request, reply) {
                reply(request.pre.m1 + ' ' + request.pre.m2);
            };
            server.route(...
                config: {
                    pre: [
                        [
                            // m1 and m2 executed in parallel
                            { method: pre1, assign: 'm1' },
                            { method: pre2, assign: 'm2' }
                        ],
                        { method: pre3, assign: 'm3' },
                    ],
                    handler: function (request, reply) {
                        reply(request.pre.m3 + '\n');
                    }
                }
            });

Views

Hapi will support all of the major template engines

var server = new Hapi.Server({
                views: {
                    engines: { html: require('handlebars') },
                    path: __dirname + '/templates'
                }
            });

            var handler = function (request, reply) {

                var context = {
                    title: 'Views Example',
                    message: 'Hello, World'
                };

                reply.view('hello', context);
            };

Static content

Hapi gives the developer precise control over hosting

static content

{ 
                method: 'GET',
                path: '/images/{path*}, 
                handler: { 
                    directory: './public/images',
                    listing: false
                } 
            }

server options

Hapi has many configurable options

Built in support for CORS

Can configure cache at server level

Well documented

Cookies

Hapi.state object used for configuring cookies

var handler = function (request, reply) {
                var maxCookieSize = 512;
                var cookieOptions = {
                    encoding: 'iron',
                    password: 'secret'
                };
                var content = request.pre.user;
                Hapi.state.prepareValue('user', content, cookieOptions, function (err, value) {
                    if (err) {
                        return reply(err);
                    }
                    if (value.length < maxCookieSize) {
                        reply.state('user', value, { encoding: 'none' } );
                    }
                    reply('success');
                });
            };

DEMo time

Questions

Resources

http://hapijs.com/ provides great documentation

Git repo found at https://github.com/spumko/hapi/

My Git repo for tonights Demo:

https://github.com/davidfekke/jaxnodeHapi

Eran Hammer's blog: http://hueniverse.com/

contact

David Fekke at gmail dot com

Twitter: @davidfekke