Real World AngularJS recipes: beyond TodoMVC

Sonia Pini – Carlo Bonamico

Real World AngularJS recipes: beyond TodoMVC

[email protected] - NIS s.r.l. [email protected] - NIS [email protected] – Genova Java User Group

Twitter: @carlobonamico @nis_srl

ROME 27-28 march 2015

We all love TodoMVC● Great resource

– discover and approachnew front-end technologies

http://todomvc.com/examples/angularjs   

● You got captured by Angular power and simplicity– have chosen it

for your next project – or thinking about it

While in the “Write App” step...● But it's difficult!

● Angular is

not suited to production, then?

● What's the matter?

http://www.bennadel.com/

Data Binding is just the beginning

It doesn’t just magically generate maintainable and extensible apps

● How to design and implement a robust HTML5 SPA?

{{ iceberg.tip }}

Modules test

Routing

directives

The questions we all ask...● Which language do we use?

● How do we split the app in modules?● How do we organize our App's structure?

● Do I really need to learn directives?

● How do we package our App for development and production?

● How do we test our App?

– this talk shares practical recipes from our real world Angular development experience

Which language do I use?

But don't you just need to use plain javascript?

ES5 vs ES6 vs TypeScript● First of all: know your JavaScript (ES5)

– do not use it like Java / C#!– learn variable scopes, closures, object-based

inheritance, idioms– some starting points at the end

● JS is not the only choice:– ES6 – the future of Web– TypeScript – typed superset of ES5 → ES6

● Angular 2.0 will fully support ES5– But will make even more things for you in ES6 and TS

● error detection, IDE support, easier Dependency Injection

Angular 2.0 friendly

Examples● ES6 - Controller ● TypeScript - Controller

How do we split the app in modules?

Modularization guidelines

Modularity is the separation of a system’s into a set of logically indipendent pieces Common design principles a module should follow:● High Cohesion - Single Responsibility Principle

(SOLID Principle)● Low Coupling - low dependency● See also R.Martin's Principles of Package Design– CCP The Common Closure Principle

● Classes that change together are packaged together

– CRP The Common Reuse Principle● Classes that are used together are packaged together

– And more http://butunclebob.com/ArticleS.UncleBob.PrinciplesOfOod

How do we can map functionalities into Angular Modules?

Modularity – Style Guide● Separate Module in category as described in John

Papa’s AngularJs Styleguide– Reusable Blocks - common service e.g. exception

handling, logging, security– Feature Modules - app specific features– App Module - thin module used for pulling together the

application

Webmail App

Logging Auth UI Widgets

Message List Reader

Message Composer Contacts

How do we arrange source code?

Typical Hello World folder Structure

A directory for each type of objectapp/

----- controllers/

---------- main.controller.js

---------- other.controller.js

----- directives/

---------- main.directive.js

---------- other.directive.js

----- services/

---------- user.service.js

---------- item.service.js

----- js/

---------- bootstrap.js

---------- jquery.js

----- app.js

views/

----- mainView.html

----- otherView.html

----- index.html

Finding files and debugging becomes difficult

as the application grows in size

Modular Structure● Feature-based

– a module / folderfor each feature or macro-component

app/

----- app.module.js

----- app.config.js

----- components/

---------- calendar.directive.js

---------- calendar.directive.html

---------- user-profile.directive.js

---------- user-profile.directive.html

----- people

---------- people.module.js

---------- people.config.js

---------- attendees.html

---------- attendees.controller.js

---------- attendees.controller.spec.js

---------- speakers.html

---------- speakers.controller.js

---------- speakers.controller.spec.js

----- services/

Features are the high-level section of the application, often corresponding to top-level routes

What is the right size of controllers?

Controller Granularity: from this

Image courtesy of Todd Motto's very interesting tutorialhttps://www.thinkful.com/learn/angularjs-tutorial-build-a-gmail-clone

    WebMailController

Controllers: to this

   WebMailController

MessageListControllerFolderListController

MsgActionController

Controller tips● Controllers should be as small as possible– used just to prepare the model and react to user inputs– avoid DOM manipulation

● Prefer the new Controller As syntax<div ng­controller=”MsgController as msgCtrl”>

{{msgCtrl.message.subject}}

function MsgController()  //no $scope!{

this.message = { subject : “Hello World” };}

Easier to test, maintain, Reduces code duplication (DRY)

Angular 2.0 friendly

How can many small Controllers / Components interact?

Collaborating Controllers– Through the Scope hierarchy

● Child controller reads/write its parent scope (or vice-versa)● ONLY suited for controllers of tightly coupled parts● Avoid if possible

– Through a common Service● Best used within a module

– MessageListController   MessageListService→– NavigationController   MessageListService→

– Through events ● Best used across modules or independent functionalities● e.g. from in Contact module choose one from list

$broadcast(“composeEmail”,         {action: “compose”, to: currentContact})

● Message Composer module listens and creates a new mail– $on(“composeEmail”, function (event) {...})

Do I really need to write Directives?

Directive Roles● Directives (together with Dependency Injection) are

the key to Angular powers– initial learning step but definitely worth doing!

● First concept: directive have different roles– Element → creates a new tag <my­autocomplete>– Decorator → adds behaviour to an existing tag ng­hide– Template → manipulate the page structure ng­repeat

● Containers are a special type of template <my­panel> 

● There are standard “recipes” and tips for each role– See http://ng-book.com

Will be explicit in

Angular 2.0

Directive tips● Progressively implement a hierarchy of Directives

– Utility directives– show­tooltip­on=”warning”

– Ui elements<contact­autocomplete></contact­autocomplete>

– Reusable Components● Tip – learn transclusion!

– <message­composer message=”newMessage”                   on­send=”wmCtrl.sent()”>

<my­custom­message­action­bar></...>– </message­composer>

– Macro-component (optional, but...)

Thinking in Components: from this

     ng­controller=”WebMailController”

ng­controller=”MessageListController”MessageList.html

Ng­controller=

”FolderListController” MsgAction

Controller

Thinking in Components

– more references on how to do this at the end

<message­list><folder­list>

<message­actions>

<message­details>

<message­search­box>

Angular 2.0 Friendly !!

So we are done now :-)

let's just copy the folder in our production web server...

Some things are missing!● Security● Logging● Packaging and Optimizations● Testing

Authentication & Authorization● Traditional Request-Response web applications

(think JSP, ASP, PHP) typically use – cookies with session ID– session data on the server– login opens a new session on the server

● You can technically do this in a Single Page App – but not a good match to REST (stateless) services

● Use Token-based authentication – and remember to check access permissions

in the REST endpoints!

JWT - http://jwt.io/● JWT = encoded & signed Json object containing

– Access token– Signed Claims (customizable!)

● Username● Expiration

● Returned by login REST service● Sent as header at each request

– Authentication: bearer eyJhbGciO.eyJzdWIiOWV9.eoaDV

● Checked by REST backed at each request– can also be used with websockets

● Angular Libraryhttps://github.com/auth0/angular­jwt 

{  “user”: “sonia”,   “company”: “NIS” }+ HMACSHA256

Logging● If you move a significant part of your app to the

client side, you need to know what's happening– are there errors?

● Our approach: – intercept all exception on the client

● $exceptionHandler service

– represent exception as event JSON object{ event: “exception”, date: …, message: , severity: }

– LogService which sends events to REST endpoint● Can also be used to collect and send metrics to the

server

Packaging: different needs

Development Time

● Live reload● No caching● No minify for debug● A file for each

class/controller/service● Mock REST services

Production Time

● Image Optimizations● CSS Optimizations● Minify● A few files to speed up

download● Real REST services

Solution: use workflow tools● Gulp

– http://gulpjs.com/● Grut

– http://gruntjs.com/ ● Tips

– Use workflow tool from the beginning– Generators helps you to kickstart new App

● Customize the result following your needs– http://yeoman.io/

– We use– https://github.com/Swiip/generator­gulp­angular 

But do I need to test my app?

Testing is nice – BDD even morein theory, but...

Testing web / Javascript applications is difficult...

Testing Angular Apps is easier● Unit test = Karma & Jasmine

– it isn't a waste of time → has saved us HOURS– use dump(var)

instead of console.log(var)

– use mocking – angular­mocks.js

● Integration test – test controllers

with services– use mock

of backend● $httpBackend 

Testing Angular Apps is easier● Functional / E2E Test = Protractor

– emulates user actions / search elements in the page– special Angular support

● Automatically waits for async actions & match by model

BDD with Protractor + Cucumber● Acceptance Test → Focus on the Customer

– sit down with your customers – describe the feature in natural language and review it– use the result as blueprint to guide your development

Page Object ● Using Page Objects to organize tests

– encapsulate information about your page structure– reusable across multiple tests– if the template of your App changes, you only need to

update the Page Object

Test pyramid vs cupcake

http://martinfowler.com/bliki/TestPyramid.html

References● StyleGuide

– https://github.com/johnpapa/angular­styleguide 

● SOLID Principles– http://butunclebob.com/ArticleS.UncleBob.PrinciplesOfOod

● Javascript by Yakov Fain – http://enterprisewebbook.com/appendix_a_advancedjs.html– https://www.youtube.com/watch?v=X1J0oMayvC0

● Axel Rauschmayer Speaking Javascript– http://speakingjs.com/ 

● TypeScript– http://www.typescriptlang.org/

● ES6– http://www.2ality.com/2014/08/es6­today.html

References● Component based directives

– http://tech.opentable.com/2015/02/10/reusable­components­angular/

– https://leanpub.com/web­component­development­with­angularjs/read

● Angular 2.0– http://angular.io/

● NG-Conf 2015 Playlist– https://www.youtube.com/playlist?list=PLOETEcp3DkCoNnlhE­7f

ovYvqwVPrRiY7

● Cucumber● https://cukes.info/ ● https://github.com/cucumber/cucumber­js 

Thank you!

● Other presentations– http://www.slideshare.net/carlo.bonamico/presentations

● Follow us on Twitter– @carlobonamico @nis_srl

● updates on AngularJS!● and some Docker, Ansible, Continuous Delivery

● Contact us– [email protected] / [email protected] – [email protected]

● Our company– http://www.nispro.it

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