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Why this code got error "Hi is not a function"

When user clicks on .step, the jquery will execute the hello function which works fine. The hello function will call hi function => I got error here: Hi is not a function
jQuery(document).ready(function( $ ) {
const form = {
init: function() {
$('.step').on('click', this.hello)
},
hello: function() {
console.log('Index: ', $(this).index()); // I can get the right index
this.hi(); // ERROR: Hi is not a function!
},
hi: function() {
console.log('HI')
},
}
form.init()
})
When I put the code like this, it works fine
jQuery(document).ready(function( $ ) {
const form = {
init: function() {
$('.step').on('click', this.hi) // Look here
},
hi: function() {
console.log('HI')
},
}
form.init()
})
Can you guys explain why?

Hi is not a function
Can any one explain why?
In this code
init: function() {
$('.step').on('click', this.hello)
},
hello: function() {
console.log('Index: ', $(this).index()); // I can get the right index
this.hi(); // ERROR: Hi is not a function!
},
you setup form.hello as an event handler for the click event. Within event handlers, this is the element that was clicked, as in:
$("button").click(function() { console.log(this.id); }
the button will (given this code) not have a .hi method.
How can we avoid the binding using Es6 or arrow function?
If you don't need to know which button was clicked, you can use an arrow function when defining the event handler:
init: function() {
$('.step').on('click', () => this.hello())
},
Example: https://jsfiddle.net/mcuh5awt/2/
Ideally, you'll want to access both the button and the form class, this is possible in two ways, the first is to change how you define your class, but keeping with how you've done it, we can add a new property self to store a reference to its ...well... self...
jQuery(document).ready(function( $ ) {
const form = {
self : {},
init: function() {
self = this;
$('.step').on('click', self.hello)
},
hello: function() {
console.log('Index: ', $(this).index());
self.hi();
},
hi: function() {
console.log('HI')
},
}
form.init()
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div>
<button class='step' type='button'>
Step 1
</button>
<button class='step' type='button'>
Step 2
</button>
</div>
As this becomes a public property of your class, you may prefer a different name in this case eg form to match the class name.

CollapseSidebar is not a function

I am writing a script for a project, it has a function to collapse or open the sidebar on click on hamdurger icon but when I click it gives me error
TypeError: this.CollapseSidebar is not a function
The following is my code:
(function($) {
'use strict';
var Prtm = {
Constants: {
LEFTMARGIN:'315px',
COLLAPSELEFTMARGIN: '63px',
},
PrtmEle:{
BODY: $('body'),
SIDEBAR: $('.prtm-sidebar'),
SIDENAV: $('.sidebar-nav'),
MAIN: $('.prtm-main'),
HEADER: $('.prtm-header'),
CONTENTWRAP: $('.prtm-content-wrapper'),
CONTENT: $('.prtm-content'),
PRTMBLOCK: $('.prtm-block'),
FOOTER: $('.prtm-footer'),
HAMBURGER: $('.prtm-bars'),
},
Init:function(){
this.BindEvents();
},
BindEvents:function(){
this.PrtmEle.BODY.on('click',this.PrtmEle.HAMBURGER,function(){
this.CollapseSidebar();
});
},
CollapseSidebar: function(){
this.PrtmEle.HAMBURGER.toggleClass("prtm-sidebar-closed is-active");
this.PrtmEle.BODY.toggleClass("prtm-sidebar-closed is-active");
this.PrtmEle.SIDEBAR.toggleClass('collapse');
},
};
Prtm.Init();
})(jQuery);
When I change this.CollapseSidebar to Prtm.CollapseSidebar it works properly. What I am doing wrong here and how it can be resolved?

Why it do not work? Because a function() binds its own this.
One thing you can do is to use Arrow function which do not bind its own this - like this:
BindEvents:function(){
this.PrtmEle.BODY.on('click',this.PrtmEle.HAMBURGER,() => {
this.CollapseSidebar();
});
}
Inside you click function this will refer to the window - so either you can create a temporary variable like the below or use the arrow function:
BindEvents:function() {
let $this = this;
this.PrtmEle.BODY.on('click',this.PrtmEle.HAMBURGER,function() {
$this.CollapseSidebar();
});
}

Call function inside RequireJS

Is it possible to create an object inside RequireJS?
Because, in this way, FunctionA is visible inside the Click event:
require(["library1", "library2"], function (obj1) {
$('#loginButton').click(function () {
functionA();
});
functionA() {
obj1.value;
}
});
But if i do something like this, it doesn't work:
var library = new library();
require(["library1", "library2"], function (obj1) {
$('#loginButton').click(function () {
library.functionA();
});
});
function library() {
this.functionA = function () {
obj1.value;
}
}
or
var library = new library();
$('#loginButton').click(function () {
library.functionA();
});
functionA() {
require(["library1", "library2"], function (obj1) {
this.functionA = function () {
obj1.value;
}
});
}
Is this possible?

I'm not sure why your explicit example is not working. However, I would suggest ensuring that you make jQuery a dependency in your require statement.
The following is using dojo, which uses an AMD environment like RequireJS. I just wanted to make sure that I was able to load multiple modules for my example and RequireJS has not modules with it like dojo does.
I was able to get your second example working by fixing the dependencies.
var library = new library();
require(["dojo/dom", "jquery"], function(dom, $) {
$('#button').click(function() {
library.functionA();
});
});
function library() {
this.functionA = function() {
console.log("hello");
}
}
<script>
var dojoConfig = {
parseOnLoad: false,
isDebug: true,
async: 1,
packages: [{
name: "jquery",
location: "//code.jquery.com",
main: "jquery-1.11.3.min"
}]
};
</script>
<!-- Include the dojo 1.10.4 CDN -->
<script src="//ajax.googleapis.com/ajax/libs/dojo/1.10.4/dojo/dojo.js"></script>
<main>
<button id="button" type="button">Click me</button>
</main>

How to test this with Jasmine test (Behaviour Driven Development)?

I've just developed this JavaScript/Backbone module as a part of a web page I am developing. I would like to create a Jasmine test for it, but I am brand new to Jasmine, therefore I am not sure what should I be testing in this class. What should be the "skeleton" of the test? In order to avoid redundancy in tests, what parts will you test?
editdestinationview.js:
define([
'common/jqueryex',
'backbone',
'marionette',
'handlebars',
'text!education/eet/templates/editdestination.hb',
'text!common/templates/validationerror.hb',
'lang/languageinclude',
'common/i18nhelper'
], function ($, Backbone, Marionette, Handlebars, templateSource, errorTemplateSource, i18n) {
'use strict';
var errorTemplate = Handlebars.compile(errorTemplateSource),
EditDestinationView = Marionette.ItemView.extend({
initialize: function (options) {
this._destinationTypes = options.destinationTypes;
},
onRender: function () {
this.stickit();
this._bindValidation();
},
_bindValidation: function () {
Backbone.Validation.bind(this, {
valid: this._validAttributeCallback,
invalid: this._invalidAttributeCallback,
forceUpdate: true
});
},
_validAttributeCallback: function (view, attr) {
view.$('#error-message-' + attr).remove();
},
_invalidAttributeCallback: function (view, attr, error) {
view.$('#error-message-' + attr).remove();
view.$('#destinationTypes').parent('div').append(errorTemplate({
attr: attr,
error: error
}));
},
template: Handlebars.compile(templateSource),
ui: {
saveAnchor: '#ed_eetSaveDestinationAnchor',
deleteAnchor: '#ed_eetDeleteDestinationIcon'
},
triggers: {
'click #ui.saveAnchor': 'click:saveDestination',
'click #ui.deleteAnchor': 'click:deleteDestination'
},
bindings: {
'select#destinationTypes': {
observe: 'destinationTypeId',
selectOptions: {
collection: function () {
return this._destinationTypes;
},
labelPath: 'description',
valuePath: 'destinationTypeId',
defaultOption: {label: i18n.EDUCATION_EET_SELECT_INTENDED_DESTINATION, value: null}
}
}
}
});
return EditDestinationView;
});
Thanks everyone!
UPDATE:
After thinking a lot about it, I think that I should try these aspects:
-Triggers: Check if they can be clicked.
-"_validAttributeCallback" and "_invalidAttributeCallback": Check if they behave accordingly to the code.
-Template: Spy on it to check if it is performing it's mission. (Optional test)
So, the test skeleton will be:
define([
'education/eet/views/editdestinationview'
], function (EditDestinationView) {
describe('description...', function () {
beforeEach(function () {
//EditDestinationView.triggers
});
describe('blablabla', function () {
beforeEach(function () {
// ...
});
it('blablabla', function () {
// blablabla
});
});
});
});
Any help on how to test this please?

One common pattern is to use two describe statements, one for the class and one for the method being tested, and then an it statement for each thing you want to test about that method. The rspec people have a convention (which I use in my JS tests) of using a '#' on the method describe for an instance method, and a "." for a describe of a static method.
Now, if you adopt all of the above, and you want to test (for instance) that your View's click-handling method triggers a certain event on the View's Model, it would look something like this:
define([
'education/eet/views/editdestinationview'
], function (EditDestinationView) {
describe('EditDestinationView', function () {
var view;
beforeEach(function () {
// do setup work that applies to all EditDestinationView tests
view = new EditDestinationView({model: new Backbone.Model()});
});
describe('#handleClick', function () {
beforeEach(function () {
// do setup work that applies only to handleClick tests
});
it('triggers a foo event', function () {
var wasTriggered;
view.model.on('foo', function() {
wasTriggered = true;
});
view.handleClick();
expect(wasTriggered).toBe(true);
});
});
});
});
P.S. Instead of creating a fake "foo" handler like I did, most people use a mocking library like Sinon. Using that library our "it" statement could instead be:
it('triggers a foo event', function () {
var triggerStub = sinon.stub(view.model, 'trigger');
view.handleClick();
expect(triggerStub.calledOnce).toBe(true);
expect(triggerStub.args[0][0]).toBe('foo');
//NOTE: args[0][0] == first arg of first call
});

How to call a backbone view function from another view in separate files

I have two backbone views defined in two separate files namely:
LandingView.js
define([
'jquery',
'underscore',
'backbone',
'marionette',
'text!templates/landing/landingTemplate.html',
'text!templates/invitations/invitationsTemplate.html',
'views/invitations/InvitationsView',
], function ($, _, Backbone, Marionette, landingTemplate, invitationsTemplate, InvitationsView) {
var LandingView = Backbone.View.extend({
el : $("#landing"),
id : 'landing',
transition : 'slide',
initialize : function () {
this.GetNotificationsCounts();
},
events : {
'click #invitations' : 'onInvitations',
},
render : function () {
var that = this;
$('.menu li').removeClass('active');
$('.menu li a[href="#"]').parent().addClass('active');
this.$el.html(landingTemplate);
},
cleanup: function() {
this.undelegateEvents();
$(this.el).empty();
},
onInvitations : function () {
//do something
},
GetProfile: function (userLogin) {
// do something
},
GetNotificationsCounts: function () {
// do something
},
formatAccountName: function () {
//do something
}
});
return LandingView; });
Then there is another file InvitationsView.js
define([
'jquery',
'underscore',
'backbone',
'marionette',
'views/landing/LandingView',
'text!templates/invitations/invitationsTemplate.html',
], function ($, _, Backbone, Marionette, LandingView, invitationsTemplate ) {
var InvitationsView = Backbone.View.extend({
el : $("#invitations"),
id : 'invitations',
transition : 'slide',
initialize : function () { debugger;
this.$el.attr('data-transition', this.transition);
this.currentUserLogin = currentUserLogin;
var that = this;
},
events : {
},
render : function () { debugger;
$('.menu li').removeClass('active');
$('.menu li a[href="#"]').parent().addClass('active');
this.GetUserInvitationDetails();
this.$el.html(invitationsTemplate);
},
cleanup: function() {
this.undelegateEvents();
$(this.el).empty();
},
GetUserInvitationDetails: function () {
var landingView = new LandingView();
currentUserName= landingView.formatAccountName();
curUser = currentUserName.replace("\\", "^").replace("^", "%5E");
var profilemsg = landingView.GetProfile(currentUserName);
},
});
return InvitationsView;});
Now I need to call the formatAccountName and GetProfile functions defined in the first JS to the second JS. I am unable to do that. I get errors.
When I try
var landingView = new LandingView();
currentUserName= landingView.formatAccountName();
This also fails. Can somebody help me in this regard and tell me how can I achieve this

Your current approach of calling the formatAccountName method works. The following jsfiddle shows this:
http://jsfiddle.net/v4h11qac/
The problem is likely caused by another error that has not been handled correctly, resulting in the code not being run. You should fix the existing errors and the method call should work as expected.
Orignal Answer:
You could call the method directly on the prototype object:
LandingView.prototype.formatAccountName();
If you need to pass through a new context you can use the call or apply method as below:
LandingView.prototype.formatAccountName.call(context);
A better approach might involve creating a helper module that can be shared by both views.
var viewHelpers = {
formatAccountName: function(account) {
// ...
}
};
var ViewOne = Backbone.View.extend({
render: function() {
var formattedName = viewHelpers.formatAccountName(this.model);
// ...
}
};
var ViewTwo = Backbone.View.extend({
render: function() {
var formattedName = viewHelpers.formatAccountName(this.model);
// ...
}
};
You could also use a system bus, however that may be a little too heavy for such a use case. If you want to take a look at that path, then Backbone.Radio provides a request/response pattern which could be used to fulfill this requirement.

You could use a global event dispatcher that you declare in some kind of main-js-file like this:
var vent = _.extend({}, Backbone.Events);
Then in your view, listen for an event and run function.
vent.on('your:event',this.function_to_run_from_other_view,this);
Dispatch the event like this from the other view.
vent.trigger('your:event',args)