Top 19 Backbone.js Interview Questions and Answers
Q1. What Is The Most Powerful Capabilities Of The Modelbinder ?
The most impressive capacities of ModelBinder class is that it empowers you to characterize scope when you make your ties utilizing jQuery.
Assuming your perspectives are straightforward, you can depend on default perusing decides that are dependent on the html "name" quality.
You can characterize perusing with jQuery selectors assuming that your perspectives are complicated.
Q2. What Is Backbone Events?
Spine occasions is a module that can be blended in to any object, enabling the item to tie and set off exceptionally named occasions. Occasions are not proclaimed before they will undoubtedly any item . Occasions mirrors the condition of the model.
Q3. How Might You Write The Business Logic In Model?
We can compose the strategies which contain the business rationale.
See the model underneath:
Individual = Backbone.Model.extend({
defaults: {
name: 'Hatchling',
age: 0,
kid: ''
},
introduce: function(){
alert("This class has adop() strategy which contains business rationale to set new child.");
},
take on: work( newChildsName ){
this.set({ youngster: newChildsName });
}
});
var individual = new Person({ name: "Thomas", age: 67, youngster: 'Ryan'});
person.adopt('John Resig');
var youngster = person.get("child");//'John Resig'
Q4. Make sense of What Is Backbone.js Models?
Backbone.js models are article and center of backbone.js. It contains a variety of qualities and tunes in for occasions. To address your information, Backbone gives a model article. For instance, you have a daily agenda, you would have a model addressing every thing on that rundown.
Q5. Notice What Are The Typical Problems You Might Face With The Backbone View Code?
Application models don't change frequently
Application pages are as often as possible invigorated without any preparation from the server
Between various view models are not shared
Q6. How Might You Attach Listeners To Events In A View?
Utilize the "occasions" quality of Backbone.View. Recall that occasion audience members must be appended to kid components of the "el" property.
See model underneath:
SearchView = Backbone.View.extend({
introduce: function(){
this.render();
},
render: function(){
var layout = _.template( $("#search_template").html(), {} );
this.$el.html( layout );
},
//Connect audience to click occasion of the pursuit button
occasions: {
"click input[type=button]": "doSearch"
},
doSearch: work( occasion ){
// Button clicked, you can get to the component that was clicked with event.currentTarget
alert( "Quest for " + $("#search_input").val() );
}
});
Q7. Make sense of When You Can Use Unbinding Function In Backbone.js?
At the point when you need to eliminate the approval restricting on the model or all models , eliminating all occasions attached on the assortment, you can utilize Unbinding capacity.
For instance : Backbone.Validation.Unbind(view) [ This will eliminate the approval binding]
Q8. How Might You Use Underscore Templates In Backbone.js Views?
To start with, make a highlight layout
Make div for el property of the view
Order the layout utilizing highlight
Load the ordered HTML into Backbone "el"
See the beneath model:
<script type="text/format" id="search_template">
<label>Search</label>
<input type="text" id="search_input"/>
<input type="button" id="search_button" value="Search"/>
</script>
<div id="search_container"></div>
<script type="text/javascript">
SearchView = Backbone.View.extend({
introduce: function(){
this.render();
},
render: function(){
// Incorporate the layout utilizing highlight
var layout = _.template( $("#search_template").html(), {} );
// Load the incorporated HTML into the Backbone "el"
this.$el.html( layout );
}
});
var search_view = new SearchView({ el: $("#search_container") });
</script>
Q9. Might You at any point Have Default Values For Model? If Yes, How?
Indeed, we can set default values for the model credits.
See the model beneath:
MyClass = Backbone.Model.extend({
defaults: {//sets default values
attrib1: 'Default Attribute1 Value',
attrib2: 0
},
introduce: function(){
alert("It is so natural to set default values. Isn't it?");
}
});
Q10. What Are The Three Js Files That You Require To Setup A Working Environment For Backbone?
you are required following three js records to arrangement a workplace for spine
jQuery
Spine
Highlight
In your application put these documents inside js organizer and use it in your index.html page
Q11. Make sense of What Is Backbone.js?
Backbone.js is a JavaScript client-side (front end) structure, which assists with getting sorted out your code and makes it more straightforward to foster single page applications. It permits you to structure JavaScript code in a MVC (Model, View , Controller) design.
Model: It is a piece of your code that populates and recovers the information.
View: It is the HTML portrayal of this model.
Regulator: It empowers you to save your javascript application through a hashbang URl.
Q12. What Is Backbone.sync Is Used For?
At the point when Backbone needs to save or peruse a model to the server it gets down on a capacity called as Backbone.sync.
Q13. What Is Router In Backbone.js?
Spine switches are utilized for directing your applications URLs while utilizing hash tags(#). In the customary MVC sense, they don't be guaranteed to fit the semantics and on the off chance that you have perused "What is a view?" it will expand on this point. However a Backbone "switch" is still extremely valuable for any application/include that needs URL steering/history capacities.
Characterized switches ought to continuously contain no less than one course and a capacity to plan the specific course to.
Courses decipher anything later "#" label in the URL. All connections in your application ought to target "#/activity" or "#action". (Attaching a forward slice after the hashtag looks a piece more pleasant, for example http://wisdomjobs.com/#/client/help).
<script>
var AppRouter = Backbone.Router.extend({
courses: {
"*actions": "defaultRoute"//matches http://wisdomjobs.com/#anything-here
}
});
// Start the switch
var app_router = new AppRouter;
app_router.on('route:defaultRoute', function(actions) {
alert(actions);
})
// Begin Backbone history an important stage for bookmarkable URL's
Backbone.history.start();
</script>
Q14. What Is Models In Backbone.js?
Models are utilized to address information from your server. Model in BackboneJs contains:
Intelligent information
Business Logic
Changes
Approvals
Registered properties
Access control
MyClass = Backbone.Model.extend({
introduce: function(){
alert("I will introduce the model when it is made. I'm like constructor.");
}
});
var myObj = new MyClass();
Q15. Make sense of What Is View In Backbone.js?
Spine view is a Javascript object that deals with a particular DOM component and relatives.
Sees are not HTML
It is a portrayal of a model
The HTML code comes from layouts
Works with any layout framework
Q16. How Might You Use Template Variables?
You can get to format factors with <%= %>.
<script type="text/format" id="search_template">
<label><%= search_label %></label>
<input type="text" id="search_input"/>
<input type="button" id="search_button" value="Search"/>
</script>
<div id="search_container"></div>
<script type="text/javascript">
SearchView = Backbone.View.extend({
instate: function(){
this.render();
},
render: function(){
//Pass factors in utilizing Underscore.js Template
var factors = { search_label: "My Search" };
// Order the format utilizing highlight
var format = _.template( $("#search_template").html(), factors );
// Load the ordered HTML into the Backbone "el"
this.$el.html( format );
},
occasions: {
"click input[type=button]": "doSearch"
},
doSearch: work( occasion ){
// Button clicked, you can get to the component that was clicked with event.currentTarget
alert( "Quest for " + $("#search_input").val() );
}
});
var search_view = new SearchView({ el: $("#search_container") });
</script>
Q17. In Backbone View, What Is The Use Of Setelement?
setElement work is utilized when Backbone view must be applied to an alternate DOM component.
Q18. What Is Backbone.js? How Can It Help Developers?
BackboneJs is a JavaScript system which permits the designers to make their life more straightforward by giving the beneath highlights:
Model:- Store information
Model can have audience members bound to them to distinguish changes to their qualities
Assortment: Group of models
View: Represents UI
Steering: Manages how to show fitting perspective when demand through URL
Q19. What Are The Keypoints Of Backbone?
It has hard reliance with underscore.js to make it more utilitarian and supporting a scope of helpful assortment based tasks With jQuery it has a delicate reliance
At the point when the model changes it can refresh the HTML of your application consequently
It utilizes client-side delivering system or Javascript templating to deliver html which keep away from you to implant HTML code inside JavaScript code.
For UI updates and DOM controls if offers an altogether perfect and exquisite way.
