Revision:how to use backbone

three way to create your  model:

Person = Backbone.Model.extend({})
Person = Backbone.Model.extend({
defaults:{
name:"";//Model arrow undefined data
create:new Date() //here arrow put PHP function
}
});
Person = Backbone.Model.extend({
defaults:function(){
return   {  name:"";  //Model arrow undefined data
create:new Date()
}
}
});

Read and Write:

var person = new Person({ name:”Sandy”,age:”12″});

person.get(“name”);//” Sandy”

person.set({name:”Anna”,age:”12″});//overwrite it

Create Simple View

PersonView = Backbone.View.extend({

render:function(){

var person = “<p>” + this.model.get(“user”) + “</p>”;

$(this.el).html(person);

}

});

“this.el” meaning: every View Model create a Page Scope, el means the root tag<div></div>,

Get Model data Add into HTML page

var personView = new PersonView({

model:person;

})

personView.render();

console.log(personView.el);//check the el

Get Data from the server(RESTful way)

var Person = Backbone.Model.extend({urlRoot:”/person”}); //point to the data sourse

var person = new Person({id:1}); //point to your object

person.fetch();//get /person/1

person.save();//put /person/1

var newPerson=new PersonModel(); //create a new object

newPerson.set({name:”Sandy Zhang”}); // give the an name

newPerson.save(); // insert into /person

newPerson.get(“id”); //2

newPerson.destroy();// Delete /person/2

Create Better View

var PersonView = Backbone.View.extend({

tagName:”article”,

id:”personOne”;

class:”person”,

attributes:{title:this.model.get(“name”)},

render:function(){

var person=”<p>” + this.model.get(“name”)+”</p>”;

$(this.el).html(person);

}

});

this will render html sourse:

<article id=”personOne” class = “person” title=”Sandy Zhang”>

<p>Sandy Zhang</p>

</article>

Cache of the jQuery object

$(“#personOne”).html();

in Backbone.js: $(this.el).html(); or better way : this.$el.html()

el  is  generated for the cache of jQuery object, so that it can be used repeatedly without fear of generating multiple instances of the jQuery object.

Built-in template engine(underscore template)

use render() seems not elegant ,now we use underscore template

var PersonView = Backbone.View.extend({

tagName:”article”,

id:”personOne”;

class:”person”,

attributes:{title:this.model.get(“name”)},

template: _.template(‘<p><%= name %></p>’),

render:function(){

data = this.model.toJSON();

$(this.el).html(template(data));

}

}); // Cool! looking better

Track your instance

var person = new Person({name:”sandy”}); //create a instance

person.on(“change”,function(){

alert(“Something changed on ” + this.get(“name”) );

});

person.on(“change:age”,function(){

alert(this.get(“name”) +”,Your age has been changed ”  );

});

Change data to JSON format

var person = new Person({id:1});

console.log(person.toJSON());

//or

console.log(JSON.stringify(person));

Now Add View event

var PersonView = Backbone.View.extend({

tagName:”article”,

id:”personOne”;

class:”person”,

attributes:{title:this.model.get(“name”)},

template: _.template(‘<p><%= name %></p>’),

render:function(){

data = this.model.toJSON();

this.$el.html(template(data));

},

events:{ “mouseover” :”showMore”,},

showMore:function(){…….},

});

Advance Level

1.Server <= (get) model (data) => view (rendering) => DOM

var PersonView = Backbone.View.extend({

input:_.template(‘<input type=”text”><%= name%></input>’),

submit: _.template(‘<button type=”submit”>Change Name</button>’),

render: function(){

data = this.model.toJSON();

this.$el.html(input(data)).html(submit);

}

});

Now we can  change name now, the question is how do you know the model data has changed? This needs to view it through the event.

var PersonView = Backbone.View.extend({

events:{“submit button”:”updateName”}

updataName:function(){

newName = $(this).val();  // this=button!

if(newName !== this.model.get(‘name’)){

this.model.set({name:newName}); }

else{ return;}

}

});

Well…it did work, but the problem is : should belong Model processing logic  put in the View now. So we reconstruct it.

var PersonView = Backbone.View.extend({

events:{“submit button”:”updateName”}

updateName:function(){

newName = $(this).val();

this.model.updateName(newName);

}

});

var Person = Backbone.Model.extend({

updateName: function(newName){

this.set({name:newName});

this.save(); // tell server to save the new name into database

}

})

2.The above, we pass the parameter value changes transferred to the Model, and then further processed by the Model it wants to do.

Now, the loop model like this:

Server <= (updated) model (proceed) <= (notification) view <= (user interaction) DOM

If the data model changes, how to notice the view? You might immediately think of the render method can be performed immediately after the completion notification view:

var PersonView = Backbone.View.extend({

updateName:function(){

newName = $(this).val();

this.model.updateName(newName);

this.render();

}

});

Ah good idea …… but it is not always useful, because the value of the model could be changed elsewhere, such as in another view . So, how to notify the specified view  response to the model changes?

So, use listenTo() function

var PersonView = Backbone.View.extend({

initialize:function(){

this.listenTo(this.model,”change”,this.render);

//this.model.on(“change”,this.render,this);

}

});

3. collection

a)Collect multiple model data

When there was more and more instances , in order to facilitate the processing of them, we usually think of them together with the array. Backbone.js Collection module provides a simplified way to help us:

var Person = Backbone.Collection.extend({ model:person });

var person.add{[{name:”Sandy Zhang”, id:1},{name:”Anna li”,id:2}]};

person.length //=>2

person.get(2) // => { name : “Anna li”,id:2}

person.at(0) //=>{ name:”Sandy Zhang”, id:1}

HTML5 Push State API

Backbone.history.start({pushState: true});

var App = new (Backbone.Router.extend({
initialize: function() {
this.person = new person();
this.personView = new personView({collection: this.person});
$(“#app”).append(this.personView.el);
},

index: function() {
this.person.fetch();
},

start: function() {
Backbone.history.start({pushState: true});
}
}));

$(function() { App.start(); });

2 thoughts on “Revision:how to use backbone”

  1. Hi, Sandy! Your post is awesome! It would like to follow your blog, and get excited to see your updates 🙂

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