Workshop 12: AngularJS Parte I

transcript

AngularJS - Part I

Cristina HernándezRoger Vilà

● What is AngularJS? Why Angular JS?● History of AngularJS● Angular JS Patterns● Introduce to AngularJS Code● Invoking Angular JS● DataBinding in AngularJS

● Expressions● Directives● Filters● Modules● Controllers● Services● Forms

● Application example

“Angularjs is what HTML would have been if it had been designed for building web applications”

https://angularjs.org/

What is Angular JS?

AngularJS is an open-source web application framework for client-side MVC and MVVM architectures.

Why Angular JS?

HTML is great for declaring static documents, but it falters when we try to use it for declaring dynamic views in web-applications. Angular JS lets you extend HTML vocabulary for your application

History of Angular JS

AngularJS was originally developed in

2009 by Misko Hevery at Brach Tech LLC.

Created at Google as internal project.

AngularJS version 1.0 was released in 2012.

Currently working on 1.4.9

Angular JS 2 (Beta)

https://en.wikipedia.org/wiki/AngularJS

MVC - Model View Controller

MODEL CONTROLLER

- Renders the Model data- Sends user actions/events

to controller- UI

- Defines application behaviour

- Maps user actions to Model

- Selects view for response

- Business Logic- Notifies view changes- Data in general

User Action or View Load

Maps to particular Model after fetching the data

Implements the Business Logic on response data and binds it to View

MVVM - Model View View Model

Entire model contained in a single javascript data structure.

var obj = { employeeName: "Mattias", company: "Net Insight AB" }

Controller

Javascript code that populates the view and reacts to changes in it.

function myCtrl( $scope ) { $scope = { employeeName: "Mattias", company: "Net Insight AB" };

$scope.save_info = function() { console.log( $scope.employeeName ); };}

"Extended" html. Dynamic and syncronized

<div ng-controller = myCtrl><h2>{{company}}</h2>Employee name:<input ng-model="employeeName"></input><button ng-click="save_info()"

>Submit</button></div>

Invoking Angular

Any application must do two things to start Angular:

1) Load the angular.js library

2) Tell Angular which part of the DOM it should manage with the ng-app directive

<html><div ng-app>…</div>...

</html>

<html ng-app> ....

</html>

Client-Side templatescontrollers.js:

function HelloController($scope) {$scope.greeting = { text: 'Hello' };

hello.tml:

</head><body>

<div ng-controller='HelloController'><p>{{greeting.text}}, World</p>

</div></body>

</html>

Result:

Hello, World

Data Binding

One-way binding:

Binding from scope to HTML. “Mustache” syntax

Two-way binding:

Binding from scopel to HTML, and binding from HTML to scope

Two-Way Data Bindinghello.html

</head><body>

<div ng-controller='HelloController'><input ng-model='greeting.text'><p>{{greeting.text}}, World</p>

</div></body>

</html>

controllers.js:

function HelloController($scope) {$scope.greeting = { text: 'Hello' };

Hello, World https://docs.angularjs.org/guide/databinding

Expressions

Allow you to insert dynamic values into your HTML

AngularJS expressions can be written inside double braces: {{expression}}

Angular JS expressions can be written inside a directive: ng-bind=”expression”

1) Numerical Operations

{{ 4 + 6}} → 10

2) String Operations

{{“hello” + “ you”}} → hello you

https://docs.angularjs.org/guide/expression

DirectivesDirectives are ways to expand our html. They allow you to add from small pieces of code or full functionality

Angular comes with a set of these directives built in, like:

● ng-app● ng-controller● ng-model● ng-bind● ng-repeat● ng-init● ng-show/ng-hide● ng-class● ng-click● ng-form● ng-submit● ng-if● ng-href● ng-src● custom directives (Next workshop)

https://docs.angularjs.org/api/ng/directive/

ng-modelWith the ng-model directive you can bind the value of an input field to a variable created in AngularJS

</div>

$scope.name = "John Doe";});</script>

ng-repeat<h3>FIFA Golden Ball:</h3><div ng-app ng-controller="MyCtrl"> <ul> <li ng-repeat="player in players">{{name}}: {{num}}</li> </ul></div>

function MyCtrl($scope) { $scope.players = [

{ name: “Roger”

num: 6},{

name: “Messi”num: 5

name: “Cristiano Ronaldo”num: 3

ng-show / ng-hideThe ng-show / hide directive shows or hides the given html based on the expression provided in the ng show/hide attribute

Click me: <input type="checkbox" ng-model="checked">

<span class="glyphicon glyphicon-thumbs-up"></span> I show up when your checkbox is checked.

</div>

<span class="glyphicon glyphicon-thumbs-down"></span> I hide when your checkbox is checked.

</div>

Filters● Angular filters format data for display to the user.

● Filters can be chained and can take optional arguments.

Built-in Filters

● filter● currency● number● date● json● lowercase● uppercase● limitTo● orderBy

https://docs.angularjs.org/api/ng/filter

Filters

<div ng-init="friends = [{name:'John', phone:'555-1276'},

{name:'Mary', phone:'800-BIG-MARY'},

{name:'Mike', phone:'555-4321'}]"></div>

<label>Search: <input ng-model="searchText"></label>

<tr><th>Name</th><th>Phone</th></tr>

<tr ng-repeat="friend in friends | filter:searchText |

orderBy:'name'">

<td>{{friend.name}}</td>

<td>{{friend.phone}}</td>

</table>

Filters in Javascript

$filter(‘number’)(15,5) {{ 15 | number:5 }}

Modules

- Where we write pieces of our Angular application.- Makes our code more maintainable, testable and

readable.- Where we define dependencies for our app

Modules

var app = angular.module(‘moduleName’, [] );

Dependencies

Creating:

Including the module:

<html ng-app=”moduleName”> ....

</html>

…</div>...

</html>

Modulesvar app = angular.module(‘moduleName’, [] ).config(function () { ... }).run(function () { ... });

app.controller(function(){…});

app.service(function(){…});

app.directive(function(){…});

Controllers

Controllers are where we define our app’s behavior by defining functions and values.

app.controller('ViewCtrl', ['$scope', '$location', 'recipe',

function($scope, $location, recipe) {

$scope.recipe = recipe;

$scope.edit = function() {

$location.path('/edit/' + recipe.id);

…</div>

...</html>

$scope

Scope is an object that refers to the application model.

VIEW CONTROLLER$scope

<input type=”text” ng-model=”name” />function SimpleController($scope) {

$scope.name = “Leo”;}

Services

Services are singletons objects that are instantiated only once per app.

Services are used to organize and share code across your app.

Controllers are view-specific, services are app-specific.

Built-in Services

● $http● $q● $window● $location● ...

Built-in Services - $httpvar xmlhttp = new XMLHttpRequest();

xmlhttp.onreadystatechange = function() {

if (xmlhttp.readystate == 4 && xmlhttp.status == 200) {

var response = xmlhttp.responseText;

} else if (xmlhttp.status == 400) { // Handle error gracefully}

// Setup connection

xmlhttp.open(“GET”, “http://myserver/api”, true);

// Make the request

xmlhttp.send();

$http.get('api/user', {params: {id: '5'}

}).success(function(data, status, headers, config) {

// Do something successful.

}).error(function(data, status, headers, config) {

// Handle the error

Forms and controls provide validation services, so that the user can be notified of invalid input.

This provides a better user experience.

</div>

Debugging

Batarang → Google Chrome Extension

Workshop 12: AngularJS Parte I

Software