AngularJS for Java Developers

AngularJS for Java
Developers
Loc Nguyen
lochnguyen@gmail.com

<ng-selfie/>
● Organizer of AngularJS-OC [angularjsoc.org, @angularjsoc]
● Multi-platform SW geek => Java, Ruby, JavaScript, C#, Node
● First an Ember fan (still am)
● ~1.5 years of AngularJS experience => mostly consulting

Agenda
● Thick client history
● Current state of JS
● MVC & Data binding
● Components
● Tooling
● Resources

How to train your dragon JavaScript

The Model
● Plain old Java(Script) objects – POJO!
● No need to extend a hierarchy

class Member {
String name = "";
boolean active = true;
List<String> emails = new List<String>();
}
var member = {
name: '',
active: true,
emails: []
};

The View
● Just plain HTML
● Built-in directives similar to JSTL

// index.jsp
<c:if test="${member.active}">
<c:out value="${member.name}"/>
<ul>
<c:forEach items="${member.emails}" var="email">
<li><c:out value="${email}"/></li>
</c:forEach>
</ul>
</c:if>
// index.html
<div ng-if="member.active">
{{member.name}}
<ul>
<li ng-repeat="email in member.emails">
{{email}}
</li>
</ul>
</div>

The Controller
● Plain old JavaScript functions
● Instantiated as needed
● Inject dependencies
● Figure out what the view needs, defer retrieval
● $scope is the context
o a view model

package ocjug.controllers;
@Controller
class MeetupController {
function meetupController($scope) {
$scope.person = {
name: 'Loc', active: true, emails: [...]
};
}
public String index(Model model) {
Member person = new Member();
member.name = "Loc";
member.active = true;
member.emails = Arrays.asList(...);
model.setAttribute("scope", member);
}
}
angular.module('ocjug.controllers', [])
.controller('MeetupController', meetupController);

Data Binding
● $digest loop – Angular event loop
● $watch list – what’s dirty?
● http://codepen.io/anon/pen/EcoGd

Dependency Injection
● Code to abstractions
● Testing is so easy
● SOLID
● Put controllers on a diet

Services
● Promote cleaner code
● Organization and reusability
● Shared business logic
● Data retrieval
● One instance in app
● 3 ways to make a service!

package ocjug.services;
@Service
class MeetupSearchService {
private final API_KEY = "abc123";
private final SEARCH_URI = "https://api.meetup.com/search";
@Autowired
SomeHttpClient httpClient;
public List<SearchResult> search(Map params) {
// start pseudo-ing
httpClient.queryParams(params).get(SEARCH_URI);
}
}
Example

angular.module('ocjug.services', [])
.factory('MeetupSearchSvc', function ($http) {
var API_KEY = 'abc123';
var SEARCH_URI = 'https://api.meetup.com/search';
var search = function (queryParams) {
return $http.get(SEARCH_URI, { params: queryParams
});
};
return {
search: search
}
});

Services
.service() - invoke with the new keyword
.service('MeetupSearchService', function ($http) {
this.API = 'http://api.meetup.com/search';
this.search = function() {
// ...
}
});

Services (cont)
.factory() - always use a factory!
.factory('MeetupSearchService', function ($http) {
var API = 'http://api.meetup.com/search';
return {
search: function (params) {
// …
}
};
});

Services (cont)
.provider() - configure before app starts
.provider('MeetupSearchProvider', function () {
var API = 'http://api.meetup.com/search';
this.REMEMBER_SEARCHES = false;
this.$get = function ($http) {
return {
search: function (params) {
// …
if (this.REMEMBER_SEARCHES) ...
}
};
};
});

Services (cont)
angular.module('ocjug', ['ocjug.services'])
.config(function(MeetupSearchProviderProvider) {
MeetupSearchProviderProvider.REMEMBER_SEARCHES = true;
});

angular.module('ocjug.controllers', [])
.controller('MemberSearchCtrl', function ($scope, $http) {
$http.get('http://api.meetup.com/search?name=' +
$scope.name);
})
.controller('MeetupSearchCtrl', function ($scope, $http) {
$http.get('http://api.meetup.com/search?meetup='
+ $scope.meetup);
});
Extracting into a Service

Filters
● Take an input to filter
● Easily format data in templates
● Uses the | character in {{ }} expression
{{1.456 | number:2}} => 1.46
{{'ocjug'| uppercase | limitTo:3}} => OCJ
{{99.99 | currency:'USD$' }} => USD$99.99
<div ng-repeat="m in movies | orderBy:'revenue'">

angular.module('ocjug.filters', [])
.filter('asCentimeters', function () {
return function (inches) {
return inches * 2.54;
};
});
{{2 | asCentimeters}} => 5.08

Directives
● The killer feature of AngularJS
● ...and the most complex API
● Apply liberally

Directives
● Built-in directives
○ ng-show, ng-click, ng-repeat
● Custom directives
○ reusable widgets
○ declarative programming
○ wrap non Angular libraries

// picture.tpl.html
<div>
<img ng-src="picture.url"/>
<div>{{picture.caption}}</div>
<a ng-click="fbLike(picture)">Like</a>
<ul>
<li ng-repeat="comment in picture.comments |
limitTo:3">
{{comment}}
</li>
</ul>
<comment-form picture="picture"> … </comment-form>
</div>

angular.module(ocjug.directives, ['ocjug.services'])
.directive('pic', function(FbService) {
return {
templateUrl: 'picture.tpl.html',
scope: {
picture: '=',
commentable: '@'
},
link: function ($scope, el, attrs) {
$scope.fbLike = function(picture) {
FbService.like(picture.id);
}
}
}
});

angular.module(ocjug.directives, ['ocjug.services])
.directive('commentForm', function(CommentService) {
return {
templateUrl: 'comment.tpl.html',
scope: {
picture: '='
},
link: function ($scope, el, attrs) {
$scope.submit = function(comment) {
CommentService.create(comment);
}
}
}
});

Test and Tools
● Unit tests - Karma
● E2E - Protractor
● Node based build tools
o Grunt
o Gulp

What’s missing?
● SPA vs Islands of Richness
● Async and promises
● AJAX
● Performance
● Routing
● Testing
● Mobile
● Integration

Resources
UI-Router: github.com/angular-ui/ui-router
Angular-UI: github.com/angular-ui
Ionic: ionicframework.com
Year of Moo: yearofmoo.com
Style Guide: github.com/johnpapa/angularjs-styleguide

docs.angularjs.org/tutorial
● Free!
● Beginner

codeschool.com
● Free!
● Gamified learning
● Beginner

egghead.io
● AngularJS,
● JavaScript,
● D3.js
● EcmaScript 6
● NodeJS
● ReactJS
● $10m or $100/y
https://egghead.io/pricing?dc=ng_socal
Beginner – Advanced

pluralsight.com
● $29 month
● The most Angular courses
● Deep coverage of JS
● ...and .NET
● Beginner – Advanced

angularjsoc.org
meetup.com/AngularJS-OC

AngularJS for Java Developers

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