Angular js-crash-course

Crash Course
Keith Bloomfield
Lead Developer
dev9

Crash CourseCrash Course
Show of Hands
Front-end developers?
Back-end developers?
Other?
Using AngularJs at work/home?
New to AngularJs?
Keith Bloomfield
Lead Developer
dev9

Overview
Data Binding, Expressions, Scopes,
Ng Directives
Modules, Dependency Injection
Controllers, Services, Factories, Directives
Unit Testing
End-to-End (e2e) Testing
Continuous Integration
Real World Experiences
Tool Support
Resources for Learning
Q&A
Crash Course
Agenda

Overview
● AngularJs is a Spa framework
● Manicure/Pedicure
● Body/Facial Treatment
● Massage
● A lot has changed on
the front-end in the last
few years!

Overview
● Single-Page Application (dynamic views)
● Recommends client-side Model-View-Controller (Mvc) pattern

Overview
Don't
know about
each other.

Overview
Implications:
Routing
History
Caching
Packaging
Deployment
Automation
Data Binding
Object Modeling
Timing/Dispatch
Templating
Testing
Storage
...
AngularJs

Overview
What becomes
of this?

Overview
Model-View-Whatever (Mvw)

The View
● Templates/Partials
foo.html
Html content swapped into/out of the single page
my-app.html
my-header.html
my-cart.html
my-news.htmla2.htmla2.html
bn.html
c1.html
a1.html a3.html
b3.html
b2.htmlb1.html
c2.html
d.html
my-mail.html
my-tools.html

Data Binding, Expressions and
Scopes
● Extending Html's vocabulary: Directives
– Extend Html as markers on the Dom
– Can be used as an attribute, element, class name, comment
– Tell AngularJs' compiler ($compile) to attach specific behavior to that
Dom element or even transform that element and its children.
<!DOCTYPE html>
<html ng-app>
<head>
<title>echo</title>
</head>
<body>
<div class="container">
Name: <input type="text" ng-model="echo"/>
<br/>
{{ echo }}
</div>
<script src="scripts/angular.min.js"></script>
</body>
</html>
Angular (ng)
Directives
Data Binding
Expression
“The compilation is a process
of walking the DOM tree and
matching DOM elements to
directives.”
(links scope to template)

Scopes
<!DOCTYPE html>
<html ng-app>
<head>
<title>echo</title>
</head>
<body>
Name: <input type="text" ng-model="echo"/>
<br/>
{{ echo }}
</div>
<script src="scripts/angular.min.js"></script>
</body>
</html>
auto-bootstraps the
AngularJs application/
designates the root
element.
binds input, select, textarea to a
property on the scope using ng-model
(NgModelController), and more.
Evaluated against
the scope.

Scopes

Scopes
● The only place where an AngularJs application
touches the Dom is within directives.
● This is good as artifacts that access the Dom
are difficult to test.
More about directives later, but first...

Scopes
● $scope
● Acts as the glue between the view and the controller
● Refers to the application model
●
Arranged hierarchically to mimic the Dom
●
Can inherit from parent scope
● Can watch expressions and propagate events

Scopes
● $scope
● $rootScope: Defined at the top level of the application (where the
ng-app directive is applied)
● Lookup proceeds up the scope chain when a variable is not found
in the local scope.
● Relying on scope is risky because the Dom layout is often changed.
- Isolating scope protects against changes to the Dom hierarchy.

Scopes
● $scope
● $watch: Observe model mutations
● $apply: Propagate model changes through the system into the view
from outside the Angular realm (controllers, services, ng event
handlers). Triggers $digest, which can be used directly in unit tests.
● Also available: $watchCollection, $destroy, $eval, $evalAsync, $on,
$emit, $broadcast

Dependency Injection
● Reusable container for different features of
your app
Module

● Has two phases:
– config: setup providers and constants
– run: after injector is created, kickstart the app
angular.module('myModule', ['moduleDependency1', 'moduleDependency2',....])
.config(function(injectable1, injectable2,...) { // provider-injector
// Use as many of these as you want.
// Can only inject Providers (not instances)
})
.run(function(injectable1, injectable2,....) { // instance-injector
// Use as many of these as you want.
// Can only inject instances (not Providers) and constants
});
Module

Module
● Features can be bundled and injected in/as
modules

● $provide
- Object in module auto
● auto
- Implicit module which gets automatically added to each $injector
● $injector
- used to retrieve object instances as defined by provider, instantiate types,
invoke methods, and load modules.

● $provide
- Helper methods (also exposed on module):
● provider(provider) - registers a service provider with the $injector
● constant(obj) - registers a value/object that can be accessed by providers and
services.
● value(obj) - registers a value/object that can only be accessed by services, not
providers.
● factory(fn) - registers a service factory function, fn, that will be wrapped in a
service provider object, whose $get property will contain the given factory
function.
● service(class) - registers a constructor function, class that will be wrapped in a
service provider object, whose $get property will instantiate a new object using
the given constructor function.
● Worth investigating: $provide.decorator() // $provide only
https://egghead.io/lessons/angularjs-provide-decorator

● $provide
- Helper methods (also exposed on module):
● provider(provider) - registers a service provider with the $injector
● constant(obj) - registers a value/object that can be accessed by providers and
services.
● value(obj) - registers a value/object that can only be accessed by services, not
providers.
● factory(fn) - registers a service factory function, fn, that will be wrapped in a
service provider object, whose $get property will contain the given factory
function.
● service(class) - registers a constructor function, class that will be wrapped in a
service provider object, whose $get property will instantiate a new object using
the given constructor function.
“Where is the Controller?”
● Added to the Dom using ng-controller
● The ng-controller directive asks the injector
to create an instance of the controller and its
dependencies.
● The controller itself never knows about the
injector.
● Loose coupling is maintained.

● Dependencies are looked up by name for a
provider that satisfies the argument.
app.controller(“AController”, function($scope, $http){
$scope.userName = 'Walt';
$scope.foo = $http.get('http://foo.com');
});
a.controller(“AController”, function(b, c){
b.userName = 'Walt';
b.foo = c.get('http://foo.com');
});
● Minified: Order doesn't matter
$scope found in
ng module
- $rootScopeProvider
- $rootScope.Scope
$http service found
ng module
- $http
OH NO!

● Longer version preserves dependency by
treating it as an argument:
app.controller(“AController”, ['$scope', '$http', function($scope){
$scope.userName = 'Walt';
$scope.foo = $http.get('http://foo.com');
}]);
a.controller(“AController”, ['$scope', '$http', function(b, c){
b.userName = 'Walt';
b.foo = c.get('http://foo.com');
}]);
● Minified: Order matters
Passed in as arguments
to the function

● Minification Pain Relief: ngmin
https://github.com/btford/ngmin
It turns this
angular.module('whatever').controller('MyCtrl', function ($scope, $http) { ... });
into this
angular.module('whatever').controller('MyCtrl', ['$scope', '$http', function ($scope, $http) { ... }]);

Controllers
● Used to augment the Angular scope
● Attached to the Dom via the ng-controller directive
● Set up the initial state of the $scope object
● Add behavior to the $scope object
<html ng-app="pizza-shop">
<head></head>
<body ng-controller="HomeController">
<header ng-include="'templates/header.html'">
</header>
<h2>Our Pizzas:</h2>
<div ng-repeat="pizza in pizzas">
<h3>{{ pizza.name }}</h3>
...
app.controller('HomeController', function($scope){
$scope.pizzas = [
{
name: "Meat Lover's",
ingredients: ['Sausage','Pepperoni','Bacon','Olives'],
price: 6
},
{
name: 'Hawaiian',
ingredients: ['Canadian bacon','Pineapple'],
price: 5
},
];
});

!Controllers
● Do not use a controller to:
● Manipulate the Dom
- Business logic only. Presentation logic affects testability and belongs in directives
● Format input
- Use angular form controls instead: https://docs.angularjs.org/guide/forms
● Filter output
- Use angular filters instead: https://docs.angularjs.org/guide/filter
● Share code or state across controllers
- Use angular services instead: https://docs.angularjs.org/guide/services
● Manage the life cycle of other components
- eg: Using a controller to create a service instance

Services
● Stateless, injectable argument providing the
instance of a function passed to
module.service
● Singleton: delayed/lazy loaded (Not instantiated
until used), only instantiated once
● Good for cross app/controller communication
(sharing of utility functions)
service(class) - registers a constructor function, class that will be
wrapped in a service provider object, whose $get property will
instantiate a new object using the given constructor function.

Factories
service factory
module.service('MyService', function() {
this.method1 = function() {
//..
}
this.method2 = function() {
//..
}
});
module.factory('MyService', function() {
var factory = {};
factory.method1 = function() {
//..
}
factory.method2 = function() {
//..
}
return factory;
});
factory(fn) - registers a service factory function, fn, that will be wrapped in
a service provider object, whose $get property will contain the given
factory function.

Services, Factories, Values, Constants
● Are convenience methods for making providers
● Serve to avoid polluting the global namespace

● The difference between factory and service is the
difference between a function and an object.
● Factory(give it a function)
● Service(give it a constructor)
● Further study (object vs. function):
http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript
● Further study (ng factory vs. service):
http://iffycan.blogspot.com/2013/05/angular-service-or-factory.html
https://www.youtube.com/watch?v=A6cJasNBkyI
service vs. factory

● Either can be a primitive, object, or function
● Constant can be injected into services, controllers, or
module configs
● Value can only be injected into services and controllers
value vs. constant
“Why can't value be injected into module
config?”
The injector has not been setup yet.
Constants (special case) are accessed by their
name alone, cannot be changed, and aren't
accessed through a provider $get.

● Are convenience methods for making providers
You can also create your own providers:
app.config(function($provide){
$provide.provider('MyProvider',{
$get: function(){
return{
foo: function(){
return 'bar';
}
}
}
})
});

Directives
Isolate Scope: Directive-specific scope
– Assists in creating reusable components
– Prevents or other components from changing your
model state
app
.controller("myController", function($scope){
$scope.doSomething = function(something){...};
})
.directive('myDirective', function () {
return {
restrict: "E",
scope:{
done:"&"
},
template:'my-template.html'
}
});
The 'scope' option
isolates the directive's
scope.

Directives
Directive Definition Options: Instructions to the ng compiler
app
})
return {
restrict: "E",
priority:sort order before compilation,
terminal: if true, process this directive last,
scope: true, false, or {} (isolate)
controller: instantiate before pre-linking phase...,
require:..another directive and inject its controller...
controllerAs:controller alias at the directive scope...
type: doctype ('html','svg','math'),
template:replace current element with....
templateUrl: same as above, but async from url...
replace: where to insert template...,
transclude: precompile element.....,
compile: transform template Dom...,
link: update Dom, register listeners...,
}
restrict:
matching restriction
options:
'A' - only matches attribute name
'E' - only matches element name
'C' - only matches class name
'M' - only matches comment
or any combination.
(eg: 'AE')
default: 'A'

Directives
Directive Definition Options: Instructions to the
compiler
app
})
return {
restrict: "E",
priority:sort order before compilation,
terminal: if true, process this directive last,
scope: true, false, or {} (isolate)
controller: instantiate before pre-linking phase...,
require:..another directive and inject its controller...
controllerAs:controller alias at the directive scope...
type: doctype ('html','svg','math'),
template:replace current element with....
templateUrl: same as above, but async from url...
replace: where to insert template...,
transclude: precompile element.....,
compile: transform template Dom...,
link: update Dom, register listeners...,
}
Deferring to api:
https://docs.angularjs.org/api/ng/service/
$compile#description_comprehensive-directive-
api_directive-definition-object

Unit Testing
● Test on real devices
● Remote control
● Testing framework agnostic (Jasmine, Mocha, QUnit...
or write adapter)
● Simple CI integration (Jenkins, Travis, Semaphore)
● Open Source
● Easy to debug from IDE
Karma

Protractor
● Thin wrapper for webdriver.js
● Support for cross-browser testing using
Selenium Webdriver
● Support for GhostDriver/PhantomJs (Wip)
● Includes webdriver-manager for drivers,
Selenium installation, and updates to both
● Includes elementExplorer for building locators
● Integrates with Saucelabs, easy enough to port
over to BrowserStack

● Protractor
– Recommends the Page Object Model design
pattern for testing

● Protractor
var flow = browser.driver.controlFlow();
// pseudocode
login = function(username){...}
navigateToReviews = function(){...}
addNewReview = function(){...}
flow.execute(login('Walt'));
flow.execute(navigateToReviews);
flow.execute(addNewReview);
(Optional) Tap into webdriver.js:

Continuous Integration
● Jenkins + NodeJs plugin
● Unit tests run via Grunt and Karma
● e2e tests are still a work-in-progress:
– Rely on npm concurrent, connect(express), scripts for setup +
watch and teardown
– Awaiting reintroduction of timing in Jasmine for PhantomJs tests
– Awaiting Saucelabs/BrowserStack credentials for cross-browser
tests

Real World Experiences: Project
Challenges
Project challenges are similar to those of all
large projects:
● Discovering and establishing best practices amongst
contributors
● Directory structures/file taxonomy, refactoring with project
growth
● Keeping libraries up do date, Bower in the loop
● Rediscovery of conveniences found in mature frameworks
● Multiple solutions, evaluation, and selection

Real World Experiences: New
Challenges
● Adjustments for all
Ramp up on new framework and concepts
Continuous delivery and deployment challenges (binary artifacts, externalizing conf)
Various tools/tools in motion (grunt, node/npm, bower, css compilers, yeoman)
● Front-end veterans
New conventions, structures, design patterns (not just jquery, js, css any more)
More responsibility for application architecture
● Back-end veterans
Javascript as the primary language (callbacks, promises, debugging, refactoring..)
UX, responsive
Coordination with rest apis and content delivery service

Real World Experiences:Gotchas
● Potential for memory leaks/weird behavior with scope misuse
● Bower gone wild
● Dependency additions, revisions (npm need-to-know)
● Library/dependency bloat
● Issues/feature requests in (ng and integrated) libraries and tools

Tool Support: IDEs & Refactoring
● IntelliJ Idea, WebStorm
● Vim, SublimeText
● Netbeans
● Visual Studio
Behold the
Plug-Ins!

Tool Support: Misc. Open Source
Frameworks
● Yeoman (Yo, Grunt, Bower) + generators
http://yeoman.io/
● Lots of Grunt plugins
● Lots of Npm packages
● Batarang plugin for Chrome
● Browser web developer console

Tool Support: Static Code Analysis
● JsHint: http://www.jshint.com/
● grunt-contrib-jshint:
https://github.com/gruntjs/grunt-contrib-jshint
● Enforces code quality using rules
● Configured tasks in grunt pass directly to jshint
● Customizable
– reporter output,
– options and globals
– ignores for specific warnings
● grunt-contrib-concat: Linting before and after concatenating files

Tool Support: Code Coverage
● Karma + Istanbul: karma-coverage
https://github.com/karma-runner/karma-coverage
● Generates reports in several formats including Cobertura xml
(integration with Jenkins)
● Protractor
(none, lots of unit tests, REST apis covered on their end)

Resources for Learning
● stackoverflow
● angularjs.org
● AngularJs api docs: https://docs.angularjs.org/api
● github (docs, plunkers, demos)
● egghead.io (free and subscription)
● AngularJs Style Guide:
https://google-styleguide.googlecode.com/svn/trunk/angularjs-google-style.html
● angular-phonecat tutorial:
http://docs.angularjs.org/tutorial
● Los Techies AngularJs:
http://lostechies.com/gabrielschenker/2014/02/26/angular-js-blog-series-table-of-content/

Demo examples: https://github.com/kthblmfld/angularjs-from-scripts

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