Gettings started with the superheroic JavaScript library AngularJS

20th June 2014, Armin Rüdiger Vieweg (@ArminVieweg)
Getting started with superheroic JavaScript library AngularJS
Getting started with the superheroic
JavaScript library

Armin Rüdiger Vieweg
PHP, TYPO3, JavaScript developer
About the author
❖ 30 years old from Linz am Rhein (DE)
❖ 4.5 years experience with TYPO3
➢ published 17 extensions in TER
❖ Working with AngularJS for ~1 year

Workshop Schedule
1. Presentation
2. Live Coding Examples
3. Practicing AngularJS

AngularJS is made for...
❖ Single page applications (SPA, like Twitter)
❖ Weba pps (eg. with Cordova Framework)
❖ More complex magic on your web project

AngularJS Facts
❖ Also called just “Angular”
❖ Initially published in
2009
❖ Released under MIT
Licence
❖ Developed by Google
and community
❖ Website: angularjs.org
❖ Library file size (v1.2.17)
➢ 103 KiB production
➢ 749 KiB development
❖ Includes jqLite or uses
jQuery if existing

AngularJS Buzzwords
Dependency Injection
Two-way Data Binding
Scopes
Directives
Controllers
Filters
Providers
Services Factories Validators
ExpressionsModules

The very first steps (1/7)
❖ We need a blank HTML template
❖ And a clean folder structure:
■ app/
■ css/
■ js/
■ index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>AngularJS Workshop</title>
<link media="all" rel="stylesheet" href="css/style.css">
</head>
<body>
<script src="js/jquery-2.1.1.min.js"></script>
<script src="js/angularjs/angular.min.js"></script>

<script src="app/app.js"></script>
</body>
</html>
A blank HTML template

❖ Container for AngularJS magic
❖ You may include other modules
➢ Don’t invent the wheel twice
➢ Just reuse other modules in your applications
❖ A module is the beginning of all AngularJS projects
A module for the application

❖ In app/app.js we declare our first module:
A module for the application
// declares a module
var app = angular.module('myFirstApp', []);
app.controller(‘MyFirstController’, ...);
// also declares a module
angular.module('mySecondApp', ['myFirstApp']);
angular.module('mySecondApp').controller(...);

❖ This happens with the directive ng-app:
Lets introduce the HTML to our new app
<body ng-app="myFirstApp">

<script src="app/app.js"></script>
</body>
❖ It is possible to use several apps seperately on
one page

❖ Created a blank HTML template
➢ Included jQuery, AngularJS and our first module
❖ Declared first module in app.js
❖ Paired <body> with myFirstApp
➢ by using ng-app directive
Summary

❖ An awesome blank site, ready for AngularJS magic ;-)
Result

AngularJS Buzzwords
Scopes
Directives
Controllers
Filters
Providers
ExpressionsModules ✓

Directives (1/7)
❖ Everything in your DOM may be a directive:
➢ Elements (<ng-include></ng-include)
➢ Classes (class="ng-include: data;")
➢ Attributes (<b ng-include="data">)
➢ Comments ()
❖ Directives attach custom behavior to those elements
or transform them
What the $%&!% are directives?!

Directives (2/7)
❖ AngularJS provides plenty of its own directives:
AngularJS provided directives
❖ ngApp
❖ ngBind
❖ ngBlur
❖ ngChange
❖ ngChecked
❖ ngClass
❖ ngClick
❖ ngInlcude
❖ ngModel
❖ ngPluralize
❖ ngRepeat
❖ ngShow
❖ ngSrc
❖ ...

Directives (3/7)
❖ Directive ngModel:
➢ <input ng-model="foo">
➢ <input data-ng:model="foo">
➢ <input data-ng-model="foo">
➢ <input ng:model="foo">
➢ <input ng_model="foo">
➢ <input x-ng-model="foo">
❖ Might be necessary for html/xhtml validation reasons
Different syntax available

Directives (4/7)
❖ Let’s take the HTML template we have prepared and add:
Simple example of Angular’s directives (1/2)
<input type="text" ng-model="name">
<h1 ng-show="name" ng-class="{red: name=='Armin'}">
Hello, {{name}}!
</h1>
❖ name is a new scope variable
➢ ng-model binds the value of <input> to this variable
➢ {{name}} expression outputs the variable

Directives (5/7)
❖ We also add a button to set name:
Simple example of Angular’s directives (2/2)
<button ng-click="name='Penelope'">Click me</button>
❖ Clicking the button will set the scope variable name to
“Penelope”. This affects:
➢ The value of <input>, because it is two-way data bound
to variable name
➢ And the {{name}} expression, which outputs the value

Directives (6/7)
❖ Allmost every DOM element may be a directive
❖ We have learned some of Angular’s directives:
➢ ng-model, ng-show, ng-class and ng-click
❖ We have heard about scope variables
❖ We know of double curley expressions to output
{{variables}}
Summary

Directives (7/7)
❖ A dynamic application
without writing one line of
javascript code
Result

AngularJS Buzzwords
Scopes
Directives ✓
Controllers
Filters
Providers

The Big Picture (1/14)
1. Scopes
2. Controllers
3. Expressions
4. Two-Way Data Binding
or: Why AngularJS is superheroic!

$rootScope
Hello, {{name}}!
</h1>

</body>
RootScope

$rootScope
scope
<div ng-controller="SuperheroicController">
Hello, {{name}}!
</h1>
</div>

</body>
Scope inheritance

❖ Controllers create new child scopes
❖ May contain:
➢ Scope variables
➢ Scope functions
❖ Should contain only business logic
➢ Set up the initial state of $scope object
➢ Add behavior to the $scope object
Controllers

❖ Create file app/Controllers/Superheroic.js with
content:
Create the first controller
app.controller('SuperheroicController', ['$scope', function($scope){
$scope.name = 'Tom';
}]);
❖ Expression {{name}} inside of controller’s scope will
always return “Tom”

❖ May also contain functions:
Controller’s $scope
app.controller('SuperheroicController', ['$scope', function($scope){
$scope.add = function(a, b) {
return a + b;
}
}]);
❖ Expressions may also output functions and pass
parameters:
<h1>1 plus 2 equals <em>{{add(1,2)}}</em></h1>

❖ Change events for scope variables
➢ Get fired when value of defined scope variable changes
Watches
$scope.$watch('name', function(newValue, oldValue){
alert('New value: ' + newValue);
}, false);
❖ Instead of 'name' you may also use a function
❖ Can also watch deep objects (set third param to true)

❖ Double curley braces syntax
➢ Contains basically javascript
➢ Accesses scope variables and scope functions
Expressions
❖ Examples:
a. {{a+b}}
b. {{alert('Does this work?')}}
c. {{'Just outputs this string'}}
d. {{a ? a : '??'}}
e. {{user.name}}

Two-Way Data Binding

Two-Way data binding example (with one user)
Model User
{
id: 1,
name: 'Vieweg',
firstName: 'Armin',
image: 'armin.png'
}
<div class="user">
<img ng-src="path/to/{{user.image}}">
<h2>
{{user.name}},
{{user.firstName}}
</h2>
</div>

❖ Scope variables may also contain arrays of objects
❖ To work with them use the ng-repeat directive
Two-Way data binding example (with several users)
<div class="user">
<img ng-src="path/to/{{user.image}}">
<h2>{{user.name}}, {{user.firstName}}</h2>
</div>
<div class="entry" ng-repeat="user in users">
</div>
$scope.users = [
{
name: '...',
firstName: ''
},
{...}
];

❖ Very helpful extension for Google Chrome (Link)
❖ Shows and highlights scopes and its variables
Google Chrome: AngularJS Batarang

❖ AngularJS works with scopes
➢ Scopes inherit their variables/functions to child-scopes
➢ At the very top there exists one $rootScope
➢ $scope.$watch allows us to react on changes of variables
❖ Expressions work in scope context
➢ They check all scopes up to $rootScope for requested
variable or function
❖ Two-Way Data Binding does very much work for us
Summary

Result

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers
Filters
Providers

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers
Filters
Providers
Expressions ✓Modules ✓

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters
Providers

AngularJS Buzzwords
Two-way Data Binding ✓
Scopes ✓
Directives ✓
Controllers ✓
Filters
Providers

❖ Software Design Pattern
❖ Instantiates and caches used
components
How components get ahold of their dependencies

❖ From parameter names in functions:
Two notations to inject
app.controller('SuperheroicController', function($scope){
$scope.hello = 'world';
});
❖ Inline array notation:
app.controller('SuperheroicController', ['$scope', function(whatever)
{
whatever.hello = 'world';
}]);

AngularJS Buzzwords
Dependency Injection ✓
Scopes ✓
Directives ✓
Controllers ✓
Filters
Providers

Services & Factories
❖ Reuseable component
❖ A service/factory in Angular is:
➢ Lazy instantiated
➢ Singleton
❖ Angular offers several useful services
➢ They are prepended with $
➢ Do not use $ in your own services
Substitutable objects that are wired together using DI

❖ $http - For ajax requests
❖ $interval and $timeout - Repeats and delays
❖ $rootScope - Very top scope of application
❖ $location - URL and its parts of current site
❖ $window - Wrapper of global window. Useful for tests.
Selection of useful services provided by Angular

Usage example (with Dependency Injection)
app.controller('SuperheroicController',
['$scope', '$http', function($scope, $http){
$scope.getTypo3Releases = function() {
$http({
method: 'GET',
url: 'http://get.typo3.org/json'
}).success(function(response){
// ...
});
};
}]);

Writing our first factory
app.factory('Typo3Releases', ['$http', function($http){
var getUrl = 'http://get.typo3.org/json';
var typo3ReleasesService = {};
typo3ReleasesService.get = function(callbackSuccess) {
$http({
method: 'GET',
url: getUrl
}).success(callbackSuccess);
};
return typo3ReleasesService;
}]);

Inject and call our first factory
app.controller('SuperheroicController',
['$scope', 'Typo3Releases', function($scope, Typo3Releases){
$scope.getTypo3Releases = function() {
Typo3Releases.get(function(response){
// ...
});
};
}]);

Service and factory syntax compared
app.service('Typo3Releases', ['$http', function($http){
this.get = function(){
// ...
}
}]);
app.factory('Typo3Releases', ['$http', function($http){
var typo3ReleasesService = {};
typo3ReleasesService.get = function() {
// ...
};
return typo3ReleasesService;
}]);
Both have the same call:
Typo3Releases.get();

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters
Providers
Services ✓ Factories Validators

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters
Providers
Services ✓ Factories ✓ Validators

Filters
❖ Functions which modify expressions
❖ But does not touch the original data
❖ Using filters:
{{name | filter1 | filter2:option}}
Modify expressions

Filters
❖ AngularJS provides few of its own filters:
AngularJS provided filters
❖ currency
❖ date
❖ filter
❖ json
❖ limitTo
❖ lowercase
❖ number
❖ orderBy
❖ uppercase

Filters
❖ {{price | currency:'€'}} // €1,234.56
❖ {{name | uppercase}} // ARMIN
❖ {{created | date:'dd.MM.yyyy'}} // 20.06.2014
❖ Options of filters may be filled by scope variable:
{{created | date:format}}
Usage examples

Filters
Writing your own filters
app.filter('replaceVowelsWith', function(){
return function(input, option){
if (option === undefined || input === undefined) return input;
return input.replace(/[aeiou]/gi, option);
}
});
{{'Drei Chinesen mit dem Kontrabass...' | 'e'}}
Dree Chenesen met dem Kentrebess...

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters ✓
Providers
Services ✓ Factories ✓ Validators

Validators
❖ Forms and/or fields get validated
❖ By HTML5 validation notation (eg. type="email")
❖ Independent from browser validation, Angular:
➢ Checks values on its own
➢ Adds indicating classes to fields and forms (eg. ng-invalid)
➢ Adds $invalid property to scope of form
❖ You may write your own validators using directives
You're not coming in

Validators
<form name="form" novalidate>
<input type="email" ng-model="mail" name="mail" required>
<button type="submit" ng-disabled="form.$invalid">Submit</button>
</form>
Example
Show error messages in case validators fail:
<span ng-if="form.mail.$error.required">Mail is required!</span>
<span ng-if="form.mail.$error.email">No valid mail!</span>

Validators
❖ Writing a validator means writing a directive
❖ Usage example in template:
➢ <input name="number" type="number" ng-model="number"
required even-number>
➢ Input must be
✓ any input (required)
✓ a number (type="number")
✓ an even number (directive even-number)
Your own validators/directives

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters ✓
Providers
Services ✓ Factories ✓ Validators ✓

Providers
❖ Five recipes for providers:
1. Value
2. Constant
3. Factory
4. Service
5. Provider
❖ Providers are bound to modules/applications
Almost every AngularJS buzzword is made by providers

Providers
var app = angular.module('myFirstApp', []);
app.value('bestCmsEver', 'TYPO3');
app.controller('SuperheroicController', ['$scope', 'bestCmsEver',
function($scope, bestCmsEver){
this.bestCmsEver = bestCmsEver;
}]);
Small example with value and constant provider

AngularJS Buzzwords
Scopes ✓
Directives ✓
Controllers ✓
Filters ✓
Providers ✓
Services ✓ Factories ✓ Validators ✓

Advantages of AngularJS
❖ Allows you to work clean using reuseable modules
❖ Features of Angular
➢ enables completely new possibilites (2-way data binding)
➢ saves a lot of time for common tasks (like validation)
❖ Components are unittestable
❖ Further development of Angular, thanks to Google

AngularJS help
❖ Guide: https://docs.angularjs.org/guide
❖ API: https://docs.angularjs.org/api
❖ Many many articles, videos and examples on
➢ YouTube
➢ StackOverflow
➢ all over the web

Workshop Schedule
1. Presentation ✓
2. Live Coding Examples
3. Practicing AngularJS
15 minute break

Thanks for your ttention!

Gettings started with the superheroic JavaScript library AngularJS

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