3. 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();
○ });
5. 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
8. 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
9. Angular
● Declarative bindings
○ <span>{{newPerson.firstname}}</span>
● Automatic UI Refresh
○ $scope.firstname='george';
○ KO dependency tracking is a clever feature fo
problem which angular does not have.
● MVC
○ Angular likes to say MV*
10. 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.
11. 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
12. 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}}!
16. Code Comparsion
var 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; };
17. 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
18. 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
19. 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
20. Popularity
Knockout - More question tags on
Stackoverflow in Feb, as of today: 5904 vs 6554
Angular - more stars on github
10k vs. 3.7k and google searches
