Transcript
Vs.by Brandon D'Imperio
About the presenter
https://coderbits.com/Maslow/http://www.slideshare.net/MaslowB/https://nuget.org/profiles/MaslowB/
Knockout
● Inspired by what was already there in the XAML world
● Declarative Bindings○ <span data-bind="text:firstname"></span>
● Automatic UI Refresh○ self.firstname("george"); //automatically changes
the span text● Dependency Tracking
○ self.name=ko.computed(function(){■ return self.firstname()+self.lastname();
○ });
Knockout 2
● Templating○ <ul data-bind="foreach:person">
■ <li data-bind="text:firstname">○ </ul>
● Initialization○ var komodel=new PeopleModel();○ ko.applyBindings(komodel);
Knockout Model
● MVVM○ 2 way communication with the view○ The ViewModel represents the view. This means
that fields in a ViewModel usually match up more closely with the view than with the model.
○ View Communication: There is no IView reference in the ViewModel. Instead, the view binds directly to the ViewModel. Because of the binding, changes in the view are automatically reflected in the ViewModel and changes in the ViewModel are automatically reflected in the view.
○ There is a single ViewModel for each view
Knockout Html
Knockout Code
Knockout issues
● self.name= oops○ self.name('is the setter');
● binding magic variables○ $data,$parent,$root
● everything is done in one attribute○ data-bind="text:name,attr:{title:name,'data-id':
personId},click:nameclick"○ there are addons to help with this
● Code at http://embed.plnkr.co/Gs4U8m/preview
Angular
● Declarative bindings○ <span>{{newPerson.firstname}}</span>
● Automatic UI Refresh○ $scope.firstname='george';○ KO dependency tracking is a clever feature for a
problem which angular does not have.● MVC
○ Angular likes to say MV*
Angular 2
● Dependency Tracking○ $scope.fullname=function(){
■ return $scope.firstname+' '+$scope.lastname;○ };
● Templating○ <ul ng-repeat="person in people">
■ <li title="person.fullname()"> {{person.firstname}} </li>
○ </ul>● Embeddable
○ no global state, multiple angular apps in one page with no iframe.
Angular 3
● Injectable○ no main() method○ Dependency Injection is core
● Testable○ encourages behavior-view separation○ pre-bundled with mocks
● Loads more built-in stuff○ Pluralization Helper○ Localization Helper○ Currency and date formatting○ Script based templating
Angular Issues
● There's so much going on here○ Is this enterprise library? ○ or `lightweight` emberJs?
● slightly non-predictable directive naming○ ng-mousedown○ ng-class-even
● too many ways to do similar or the same things○ ngBind vs. {{text}}○ ng-bind vs. data-ng-bind vs. class="ng-class:
{expression};"○ ng-bind-template vs. {{text}} {{moretext}}!
Angular Html
Angular Code
Html Comparison <body>
<ul data-bind="foreach:people">
<li data-bind="text:firstname,attr:{title:lastname}"></li>
</ul>
<div data-role="add a new person" data-bind="with:newPerson">
<input data-bind="value:firstname, valueUpdate:'afterkeydown'"/>
<span data-bind="text:firstname"></span>
<div data-bind="text:fullname"></div>
<input type="button" data-bind="click:$root.addPerson" value="add"/>
<!-- sample complex binding -->
<div data-bind="text:fullname,attr:{title:fullname,'data-id':personId},click:$root.addPerson"></div>
</div> </body>
<body ng-app ng-controller="PersonCtrl">
<ul>
<li ng-repeat="person in people" title="{{person.lastname}}">{{person.firstname}}</li>
</ul>
<div data-role="add a new person">
<input ng-model="newPerson.firstname"/>
<span ng-bind="newPerson.firstname"></span>
<div>{{newPerson.fullname()}}</div>
<input type="button" value="add" ng-click="addPerson()"/>
</div>
<!-- sample complex binding -->
<div title="{{newPerson.fullname}}" data-id="{{newPerson.personId}}" ng-click="addPerson()">{{newPerson.firstname}}</div>
</body>
Code Comparsionvar PersonModel= function(first,last,id) {
var self=this;
self.personId=ko.observable(id);
self.firstname=ko.observable(first);
self.lastname=ko.observable(last);
self.fullname=ko.computed(function(){
return self.firstname()+' '+self.lastname();
});};
var PeopleModel= function(){
var self=this;
self.newPerson=ko.observable(new PersonModel('bob','knoblin',1));
self.people=ko.observableArray();
self.addPerson=function(){
self.people.push(self.newPerson());
self.newPerson(new PersonModel('jane','dough',self.people().length+1));
};
}; var komodel=new PeopleModel(); ko.applyBindings(komodel);
var angularmodel;
var PersonCtrl= function($scope) {
var PersonModel=function(first,last,id){
var self=this;
self.firstname=first;
self.lastname=last;
self.personId=id || 0;
self.fullname=function(){
return self.firstname+' '+self.lastname;
}; };
$scope.people=[];
$scope.newPerson=new PersonModel('bob','knoblin',1);
$scope.addPerson=function(){
$scope.people.push($scope.newPerson);
$scope.newPerson=new PersonModel('jane','dough',$scope.people.length+1);
};
angularmodel=$scope; };
Similarities
● Fast friendly data-binding● attribute-based binding● both can be fully html5 compliant● custom directives● Both are better than using jQuery for most
things● Both may occasionally benefit from a
sprinkling of jQuery
Differences
● Large adoption on knockout● Angular is backed by google● MVVM vs. MVC● Push Model vs. dirty checking● Angular has a dedicated debugging tool -
Batarang
Knockout vs. Angular
● Far more lightweight
● Easier to learn● Focuses on one
area● Much better
documentation● Should be faster● More backwards
(+IE) compat
● Concerns are better separated○ attributes and
controller/views● Has a bigger
toolbox● Does binding and
mvc● Better initialization
story
Popularity
Knockout - More question tags on Stackoverflow in Feb, as of today: 5904 vs 6554Angular - more stars on github10k vs. 3.7k and google searches
References
● http://joel.inpointform.net/software-development/mvvm-vs-mvp-vs-mvc-the-differences-explained/
● http://www.slideshare.net/basarat1/mvvm-knockout-vs-angular
● http://stackoverflow.com/questions/9682092/databinding-in-angularjs
● http://odetocode.com/blogs/scott/archive/2013/02/26/why-use-angularjs.aspx
● http://jsperf.com/angularjs-vs-knockoutjs● http://codeutopia.net/blog/2013/03/16/knockout-vs-
backbone-vs-angular/
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