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Sort JSON by specific value and group keys by sorted key if they have same value

I want to sort my JSON by date, and if there are multiple entries for a specific date, group all of them into the specific date.
This is my JSON:
[
{
"id":"3",
"time":"20:00",
"hometeam":"AC Milan",
"awayteam":"Juventus",
"prediction":"Under 2.5",
"odds":"1.75",
"competition":"Serie A",
"status":"lost",
"date":"01-11-2019"
},
{
"id":"4",
"time":"21:00",
"hometeam":"FCSB",
"awayteam":"Dinamo",
"prediction":"Draw",
"odds":"1.12",
"competition":"Liga 1",
"status":"",
"date":"01-11-2019"
},
{
"id":"1",
"time":"16:00",
"hometeam":"Chelsea",
"awayteam":"Arsenal",
"prediction":"Over 2.5",
"odds":"1.32",
"competition":"Premier League",
"status":"won",
"date":"31-10-2019"
},
{
"id":"2",
"time":"18:00",
"hometeam":"Manchester United",
"awayteam":"Liverpool",
"prediction":"1x2",
"odds":"1.45",
"competition":"Premier League",
"status":"won",
"date":"31-10-2019"
}
]
I want to order my JSON by date, and then have every match grouped by specific date and display them in HTML. So far, I'm displaying these 4 games, but I'm adding the date to every game; I would like to have the date, then the 2 games from 01-11-2019, again the date, 31-10-2019, then the rest of the 2 matches.
Here's the AJAX and HTML:
function updateList() {
jQuery.ajax({
type: "GET",
url: url
dataType: 'json',
timeout: 5000,
crossDomain: true,
cache: false,
success: function(data) {
console.log(JSON.stringify(data));
var groupedData = _.groupBy(data, function(d){return d.date});
//console.log(groupedData);
var htmlText = data.map(function(o){
return `
<div class="norm"><i class="icon-hourglass-time"></i>${o.date}</div>
<ul class="stage clearfix">
<li class="scene">
<!-- <div class="trigger"></div> -->
<div class="face" ontouchend="return true">
<a class="calendar-hour poster tasklist-gray">
<div class="max-constrain">
<div class="first-20">
<div class="cal-from"><strong>${o.time} <small>GMT</small></strong>
</div>
</div>
<div class="second-45">
<div class="teams">${o.hometeam}
<br><small>vs</small>
<br>${o.awayteam}</div><em><i class="fa fa-map-marker"></i>${o.competition}</em>
</div>
<div class="third-35 last-column">
<div class="over-under">
<div class="over-under-icon">
<div class="over-under-text-over uppercase">
<div class="over-under-number">${o.prediction}</div>
<div class="odd-number">
${o.odds}
</div>
</div>
<div class="touch-section uppercase"><span class="statusValue">${o.status}</span></div>
</div>
</div>
</div>
</div>
</a>
<div class="info">
<div class="result-top-unch uppercase"><i class="fa fa-pause"></i>…</div>
</div>
</div>
</li>
</ul>
`;
});
jQuery('.container-fullscreen').append(htmlText);
},
error: function(data) {
console.log(JSON.stringify(data));
}
});
}
Thanks for the help!

Actually what you want to do has to be done in two steps.
First, group your objects by date, you can do this with lodash, since it's already in your code.
With an ES6 approach, you could do this by defining the following function:
function groupBy(list, keyGetter) {
const map = new Map();
list.forEach((item) => {
const key = keyGetter(item);
const collection = map.get(key);
if (!collection) {
map.set(key, [item]);
} else {
collection.push(item);
}
});
return map;
}
It takes two arguments: your array and the function that'll be used to verify on which property it should group your data.
matchMap = groupBy(foo, match => match.date)
You have plenty example avalaible on SO, i checked this post
Then you just have to sort the array by dates:
let matchArray = Array.from(matchMap )
const sortedArray = matchArray.sort( (a, b) => {
const dateArrayA = a[1][0].date.split('-');
const dateArrayB = b[1][0].date.split('-');
return new Date(dateArrayA[2], dateArrayA[1]-1, dateArrayA[0]) > new Date(dateArrayB[2], dateArrayB[1]-1, dateArrayB[0])
})
since the date property is not a valid date but a string, you have to reconstruct it when comparing the different entries.
Then the result will be a dictionary with the date as key and ordered by it.
EDIT
Fetching data:
for(i=0;i<matchArray.length;i++)
{
for(j=0;j<matchArray[i][1].length;j++){
const currentMatch = matchArray[i][1][j];
//Your display logic
}
}
Hope it helps !

How can I add multiple images along with other input fields in vue js html?

My html code is
I also need to add sez which is in array format and also i need to add multiple images, need to provide add image and when clicking on it, need to add images as needed by the client
<form method="POST" enctype="multipart/form-data" v-on:submit.prevent="handleSubmit($event);">
<div class="row">
<div class="col-md-4">
<div class="form-group label-floating">
<label class="control-label">Name</label>
<input type="text" class="form-control" v-model="name">
</div>
</div>
<div class="col-md-4">
<div class="form-group label-floating">
<label class="control-label">Alias</label>
<input type="text" class="form-control" v-model="alias">
</div>
</div>
<div class="col-md-4">
<div class="form-group label-floating">
<label class="control-label">Sex</label>
<select class="form-control" v-model="sex" id="level">
<option value="Male">Male</option>
<option value="female">Female</option>
</select>
</div>
</div>
</div>
<div class="row" v-for="(book, index) in sez" :key="index">
<div class="col-md-4">
<div class="form-group label-floating">
<label class="control-label">Date </label>
<input type="date" class="form-control" v-model="book.date">
</div>
</div>
<div class="col-md-8">
<div class="form-group label-floating">
<label class="control-label"> Details</label>
<input type="text" class="form-control" book.details>
</div>
</div>
</div>
<a #click="addNewRow">Add</a>
<div class="card-content">
<div class="row">
<div class="col-md-4">
<div class="button success expand radius">
<span id="save_image_titlebar_logo_live">Signature</span>
<label class="custom-file-upload"><input type="file" name="photo" accept="image/*" />
</label>
</div>
</div>
<div class="col-md-4">
<div class="button success expand radius">
<span id="save_image_titlebar_logo_live">Recent Photograph</span>
<label class="custom-file-upload">
<input type="file" name="sign"/>
</label>
</div>
</div>
</div>
</div>
</form>
My vue js code is
addForm = new Vue({
el: "#addForm",
data: {
name: '',
alias: '',
sex: '',
sez: [{
date: null,
details: null,
}, ],
photo: '',
sign: '',
},
methods: {
addNewRow: function() {
this.seziure.push({
date: null,
details: null,
});
},
handleSubmit: function(e) {
var vm = this;
data = {};
data['sez'] = this.sez;
data['name'] = this.name;
data['alias'] = this.alias;
data['sex'] = this.sex;
//how to add images
$.ajax({
url: 'http://localhost:4000/save/',
data: data,
type: 'POST',
dataType: 'json',
success: function(e) {
if (e.status) {
vm.response = e;
alert("success")
} else {
vm.response = e;
console.log(vm.response);
alert("Registration Failed")
}
}
});
return false;
},
},
});
This is my code. I have no idea about how to add images in this case.
Can anyone please help me pass this data.
How to pass this data along with images to the backend?
I don't want to use base64 encoding. I need to just pass this image in this ajax post request along with other data

Using axios:
Template
...
<input type="file" name="photo" accept="image/*" #change="setPhotoFiles($event.target.name, $event.target.files) />
...
Code
data () {
return {
...
photoFiles: [],
...
}
},
...
methods: {
...
setPhotoFiles (fieldName, fileList) {
this.photoFiles = fileList;
},
...
handleSubmit (e) {
const formData = new FormData();
formData.append('name', this.name);
formData.append('alias', this.alias);
formData.append('sex', this.sex);
...
this.photoFiles.forEach((element, index, array) => {
formData.append('photo-' + index, element);
});
axios.post("http://localhost:4000/save/", formData)
.then(function (result) {
console.log(result);
...
}, function (error) {
console.log(error);
...
});
}
}

I'm not sure where would you like the extra images to appear, but I added them after this column:
<div class="col-md-4">
<div class="button success expand radius">
<span id="save_image_titlebar_logo_live">Recent Photograph</span>
<label class="custom-file-upload">
<input type="file" name="sign"/>
</label>
</div>
</div>
And here's the column I added — "add images": (You can try this feature here, with the updates)
<div class="col-md-4">
<ul class="list-group" :if="images.length">
<li class="list-group-item" v-for="(f, index) in images" :key="index">
<button class="close" #click.prevent="removeImage(index, $event)">×</button>
<div class="button success expand radius">
<label class="custom-file-upload">
<input type="file" class="images[]" accept="image/*" #change="previewImage(index, $event)">
</label>
</div>
<div :class="'images[' + index + ']-preview image-preview'"></div>
</li>
</ul>
<button class="btn btn-link add-image" #click.prevent="addNewImage">Add Image</button>
</div>
And the full Vue JS code (with jQuery.ajax()):
addForm = new Vue({
el: "#addForm",
data: {
name: '',
alias: '',
sex: '',
sez: [{
date: null,
details: null
}],
// I removed `photo` and `sign` because (I think) the're not necessary.
// Add I added `images` so that we could easily add new images via Vue.
images: [],
maxImages: 5,
// Selector for the "Add Image" button. Try using (or you should use) ID
// instead; e.g. `button#add-image`. But it has to be a `button` element.
addImage: 'button.add-image'
},
methods: {
addNewRow: function() {
// I changed to `this.sez.push` because `this.seziure` is `undefined`.
this.sez.push({
date: null,
details: null
});
},
addNewImage: function(e) {
var n = this.maxImages || -1;
if (n && this.images.length < n) {
this.images.push('');
}
this.checkImages();
},
removeImage: function(index) {
this.images.splice(index, 1);
this.checkImages();
},
checkImages: function() {
var n = this.maxImages || -1;
if (n && this.images.length >= n) {
$(this.addImage, this.el).prop('disabled', true); // Disables the button.
} else {
$(this.addImage, this.el).prop('disabled', false); // Enables the button.
}
},
previewImage: function(index, e) {
var r = new FileReader(),
f = e.target.files[0];
r.addEventListener('load', function() {
$('[class~="images[' + index + ']-preview"]', this.el).html(
'<img src="' + r.result + '" class="thumbnail img-responsive">'
);
}, false);
if (f) {
r.readAsDataURL(f);
}
},
handleSubmit: function(e) {
var vm = this;
var data = new FormData(e.target);
data.append('sez', this.sez);
data.append('name', this.name);
data.append('alias', this.alias);
data.append('sex', this.sex);
// The `data` already contain the Signature and Recent Photograph images.
// Here we add the extra images as an array.
$('[class~="images[]"]', this.el).each(function(i) {
if (i > vm.maxImages - 1) {
return; // Max images reached.
}
data.append('images[' + i + ']', this.files[0]);
});
$.ajax({
url: 'http://localhost:4000/save/',
data: data,
type: 'POST',
dataType: 'json',
success: function(e) {
if (e.status) {
vm.response = e;
alert("success");
} else {
vm.response = e;
console.log(vm.response);
alert("Registration Failed");
}
},
cache: false,
contentType: false,
processData: false
});
return false;
},
},
});
Additional Notes
I know you're using Node.js in the back-end; however, I should mention that in PHP, the $_FILES variable would contain all the images (so long as the fields name are properly set); and I suppose Node.js has a similar variable or way of getting the files.
And in the following input, you may have forgotten to wrap book.details in v-model:
<input type="text" class="form-control" book.details>
<input type="text" class="form-control" v-model="book.details"> <!-- Correct -->
UPDATE
Added feature to limit number of images allowed to be selected/uploaded, and added preview for selected image. Plus the "send images as array" fix.

If you're using HTML5, try with a FormData object ; it will encode your file input content :
var myForm = document.getElementById('addForm');
formData = new FormData(myForm);
data: formData

Use below templete to show/upload the image:
<div v-if="!image">
<h2>Select an image</h2>
<input type="file" #change="onImageUpload">
</div>
<div v-else>
<img :src="image" />
<button #click="removeImage">Remove image</button>
</div>
Js code:
data: {
image: '',
imageBuff: ''
},
methods: {
onImageUpload(e) {
var files = e.target.files || e.dataTransfer.files;
if (!files.length)
return;
this.createImage(files[0]);
},
createImage(file) {
var image = new Image();
var reader = new FileReader();
this.imageBuff = file;
reader.onload = (e) => {
this.image = e.target.result;
};
reader.readAsDataURL(file);
},
removeImage: function(e) {
this.image = '';
},
handleSubmit(e) {
const formData = new FormData();
formData.append('name', this.name);
formData.append('alias', this.alias);
formData.append('sex', this.sex);
formData.append('image', this.imageBuff);
...
// Ajax or Axios can be used
$.ajax({
url: 'http://localhost:4000/save/',
data: formData,
processData: false, // prevent jQuery from automatically transforming the data into a query string.
contentType: false,
type: 'POST',
success: function(data) {
console.log(data);
...
}
});
}
}

Can't render template into div

I need to render my template templates/page.html:
<section class="section">
<div class="container">
<h1 class="title"><%= title %></h1>
<div><%= content %></div>
<div><%= pages %></div>
</div>
</section>
into my div element with page-content id:
// Underscore mixins
_.mixin({templateFromUrl: function (url, data, settings) {
var templateHtml = "";
this.cache = this.cache || {};
if (this.cache[url]) {
templateHtml = this.cache[url];
} else {
$.ajax({
url: url,
method: "GET",
async: false,
success: function(data) {
templateHtml = data;
}
});
this.cache[url] = templateHtml;
}
return _.template(templateHtml, data, settings);
}});
// Models
var PageState = Backbone.Model.extend({
defaults: {
title: "",
subtitle: "",
content: "",
pages: "",
state: "games"
}
});
var pageState = new PageState();
// Routers
var PageRouter = Backbone.Router.extend({
routes: {
"": "games",
"!/": "games",
"!/games": "games",
"!/users": "users",
"!/add-user": "add_user"
},
games: function () {
select_item($("#games"));
console.log("games");
pageState.set({ state: "games" });
},
users: function () {
select_item($("#users"));
console.log("users");
pageState.set({ state: "users" });
},
add_user: function () {
console.log("add_user");
}
});
var pageRouter = new PageRouter();
// Views
var Page = Backbone.View.extend({
templates: {
"page": _.templateFromUrl("/templates/page.html")
},
initialize: function () {
this.render();
},
render: function () {
var template = this.templates["page"](this.model.toJSON());
this.$el.html(template);
return this;
}
});
$(function () {
var page = new Page({
el: '#page-content',
model: pageState
});
});
// Run backbone.js
Backbone.history.start();
// Close mobile & tablet menu on item click
$('.navbar-item').each(function(e) {
$(this).click(function() {
if($('#navbar-burger-id').hasClass('is-active')) {
$('#navbar-burger-id').removeClass('is-active');
$('#navbar-menu-id').removeClass('is-active');
}
});
});
// Open or Close mobile & tablet menu
$('#navbar-burger-id').click(function () {
if($('#navbar-burger-id').hasClass('is-active')) {
$('#navbar-burger-id').removeClass('is-active');
$('#navbar-menu-id').removeClass('is-active');
} else {
$('#navbar-burger-id').addClass('is-active');
$('#navbar-menu-id').addClass('is-active');
}
});
// Highlights an item in the main menu
function select_item(sender) {
$("a.v-menu-item").removeClass("is-active");
sender.addClass("is-active");
}
<link href="https://cdnjs.cloudflare.com/ajax/libs/bulma/0.6.2/css/bulma.min.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.3.3/backbone-min.js"></script>
<body>
<section class="hero is-primary is-medium">
<div class="hero-head">
<nav id="navMenu" class="navbar">
<div class="container">
<div class="navbar-brand">
<a class="navbar-item is-size-2">Virto</a>
<span id="navbar-burger-id" class="navbar-burger burger" data-target="navbar-menu-id">
<span></span>
<span></span>
<span></span>
</span>
</div>
<div id="navbar-menu-id" class="navbar-menu">
<div class="navbar-end">
<a id="games" href="#!/games" class="navbar-item v-menu-item is-active">Games</a>
<a id="users" href="#!/users" class="navbar-item v-menu-item">Users</a>
<span class="navbar-item">
<a href="#!/add-user" class="button is-primary is-inverted">
<span class="icon">
<i class="fas fa-user-circle"></i>
</span>
<span>Add user</span>
</a>
</span>
<div>
</div>
</div>
</nav>
</div>
</section>
<div id="page-content"></div>
</body>
But my content doesn't load... I'm a noobie in backbone.js still so can someone explain what do I doing wrong and how to fix?
ADDED
I have checked my script in debugger. It loads a template and finds my div in the render() function but I can't see any result in browser after, my div is empty still.

I created a plunker with your code, and it works fine for me: link
I think you only forgot to initialize your model:
// Models
var PageState = Backbone.Model.extend({
defaults: {
title: "Title - 1",
subtitle: "Subtitle - 1",
content: "Content",
pages: "1",
state: "games"
}
});

Knockout.js passing viewmodels value to multiple page

I am new to Knockout.js, i have 2 viewModel EmployeeviewModel and DepartmentViewModel, i am binding my first view using EmployeeviewModel its working perfect, now i need make click so i can navigate to second page which is department and in frist i need to display click EmployeeName and his department, secondly i need to display all the EmployeeName related to that department how to achive this, how i can pass my first page value to second page display related to departmentID.
function EmployeeViewModel()
{
var self =this;
var Allemployee =ko.observableArray([])
self.getEmployeedetails=function ()
$.ajax({
type: "GET",
dataType: "json",
url: baseUrl + 'xxx/xxxxxx',
success: function (data) {
self.Allemployee($.map(data, function (item) {
return new EmployeeModel(item);
}));
},
error: function (error) {
}
});
self.getDepartment=function()
{
//here i need to navigate to Department page with all department ID
}
}
function EmployeeModel(data)
{
var self =this;
self.employeeName = ko.observable(data.employeeName )
self.employeeMobile= ko.observable(data.employeeMobile)
self.employeeemail = ko.observable(data.employeeemail )
self.employeedepartmentId= ko.observable(data.employeedepartmentId)
}
function DepartmentViewModel()
{
var self =this;
var AllDepartmentemployee =ko.observableArray([])
self.getEmployeedetails=function ()
$.ajax({
type: "GET",
dataType: "json",
url: baseUrl + 'xxx/xxxxxx',
success: function (data) {
self.AllDepartmentemployee ($.map(data, function (item) {
return new DepartmentModel(item);
}));
},
error: function (error) {
}
});
}
function DepartmentModel (item)
{
self.departmentId= ko.observable(data.departmentId)
self.departmentName=ko.observable(data.departmentName)
self.employeeName=ko.observable(data.employeeName)
}
var viewModel=new EmployeeViewModel()
ko.applyBindings(EmployeeViewModel,document.getElementById("employeeDetails"))
var viewModel 2=new DepartmentViewModel()
ko.applyBindings(viewModel,document.getElementById("department"))
//html//
//First view
<div data-role="view" id="employeeDetails">
<ul>
<li>
<div data-bind="text:employeeName"></div>
<div data-bind="text:employeeMobile"></div>
<div data-bind="text:employeeemail "></div>
<div data-bind="text:employeedepartmentId"></div>
</li>
</ul>
<div>
//second View
<div data-role="view" id="department">
<div data-bind="text:employeeName">
<div>
<div data-bind="text:departmentName">
<div>
<ul data-bind:"foreach:AllDepartmentemployee">
<li>
<div data-bind="text:employeeName">
<div data-bind="text:departmentName"></div>
</li>
<ul>
<div>

You need to have a Main view model and have two sub view models for your departments and employees. Then every time you click on any employee you will have the departmentId then based on your logic you can either send a request to the server along with Id and get back all the employees under that department or you already have all departments and you just filter them based on departmentId that has been passed.
Below is an example how to handle: https://jsfiddle.net/kyr6w2x3/124/
HTML:
<div data-role="view" id="employeeDetails">
<ul >
<li>
<span class="info">Name</span>
<span class="info">Mobile</span>
<span class="info">Email</span>
<span class="info">Dept.NO</span>
</li>
<hr>
<!-- ko foreach: AllEmployee -->
<li>
<span data-bind="text:EmployeeName" class="info"></span>
<span data-bind="text:EmployeeMobile" class="info"></span>
<span data-bind="text:EmployeeEmail " class="info"></span>
<span data-bind="text:EmployeeDepartmentId" class="info"></span>
Click
</li>
<!-- /ko -->
</ul>
<div>
//second View
<div data-role="view" id="department">
<h1 data-bind="text:SelectedEmployeeName"></h1>
<div data-bind="if:AllDepartmentEmployee().length > 0">
<h3 data-bind ="text:AllDepartmentEmployee()[0].DepartmentName()"></h3>
</div>
<ul data-bind ="foreach:AllDepartmentEmployee">
<li>
<div data-bind="text:EmployeeName"></div>
<!-- <div data-bind="text:DepartmentName"></div> -->
</li>
<ul>
<div>
VM:
var employeesList = [{
employeeId : 1,
employeeName:"Mike" ,
employeeMobile :1234561 ,
employeeEmail:"Mike#example.com",
employeeDepartmentId:1},
{
employeeId : 2,
employeeName:"Alex" ,
employeeMobile :1234562 ,
employeeEmail:"Alex#example.com",
employeeDepartmentId:1
},
{
employeeId : 3,
employeeName:"Dave" ,
employeeMobile :1234563 ,
employeeEmail:"Dave#example.com",
employeeDepartmentId:1
},
{
employeeId : 4,
employeeName:"Dani" ,
employeeMobile :1234564 ,
employeeEmail:"Dani#example.com",
employeeDepartmentId:2},
{
employeeId : 5,
employeeName:"Chris" ,
employeeMobile :1234565 ,
employeeEmail:"Chris#example.com",
employeeDepartmentId:2
},
{
employeeId : 6,
employeeName:"Matt" ,
employeeMobile :1234566 ,
employeeEmail:"Matt#example.com",
employeeDepartmentId:2
}
]
var departmentsList = [
{departmentId:1,
departmentName:"Dept #1",
employeeName:"Mike"
},
{departmentId:1,
departmentName:"Dept #1",
employeeName:"Alex"
},
{departmentId:1,
departmentName:"Dept #1",
employeeName:"Dave"}
,
{departmentId:2,
departmentName:"Dept #2",
employeeName:"Matt "
},
{departmentId:2,
departmentName:"Dept #2",
employeeName:"Dani"
},
{departmentId:2,
departmentName:"Dept #2",
employeeName:"Chris "}
]
function MainViewModel(){
var self = this;
self.AllEmployee = ko.observableArray([]);
self.AllDepartmentEmployee= ko.observableArray([]);
self.SelectedEmployeeName = ko.observable();
self.LoadEmployees = function (){
// Ajax goes here to load uncomment below
// $.ajax({
// type: "GET",
// dataType: "json",
// url: baseUrl + 'xxx/xxxxxx',
// success: function (data) {
self.AllEmployee($.map(employeesList, function (item) {
return new EmployeeModel(item);
}));
// },
// error: function (error) {
// }
//});
}
self.GetDepartment = function(employee){
self.SelectedEmployeeName(employee.EmployeeName())
data = {departmentId:employee.EmployeeDepartmentId()}
// $.ajax({
// type: "GET",
// data:data,
// dataType: "json",
// url: baseUrl + 'xxx/xxxxxx',
// success: function (data) {
// HERE YOU MAY JUST GET THE LIST OF EMPLOEES FOR THIS DEPARTMENT OR YOU GET ALL AND HERE YOU FILTER
self.AllDepartmentEmployee ($.map(departmentsList, function (item) {
if(item.departmentId == employee.EmployeeDepartmentId()){
return new DepartmentModel(item);
}
}));
// },
// error: function (error) {
// }
// });
}
}
function EmployeeModel(data){
var self = this;
self.EmployeeId = ko.observable(data.employeeId);
self.EmployeeName = ko.observable(data.employeeName);
self.EmployeeMobile= ko.observable(data.employeeMobile);
self.EmployeeEmail = ko.observable(data.employeeEmail );
self.EmployeeDepartmentId= ko.observable(data.employeeDepartmentId);
}
function DepartmentModel (data){
var self = this;
self.DepartmentId = ko.observable(data.departmentId)
self.DepartmentName = ko.observable(data.departmentName)
self.EmployeeName = ko.observable(data.employeeName)
}
var viewModel = new MainViewModel();
ko.applyBindings(viewModel);
viewModel.LoadEmployees();

How to calculate grand total from a list

I'm making an POS application on mobile phone and I have a question. How do I calculate the grand total from the list of item from the database?
Here's my code
order-detail.dxview
POSApp.OrderDetail = function (params, viewInfo) {
"use strict";
var id = params.id,
order = new POSApp.OrderViewModel(),
isReady = $.Deferred(),
// Item List
shouldReload = false,
dataSourceObservable = ko.observable(),
dataSource;
function handleViewShown() {
POSApp.db.Orders.byKey(id).done(function (data) {
order.fromJS(data);
isReady.resolve();
});
// Item List
if (!dataSourceObservable()) {
dataSourceObservable(dataSource);
dataSource.load().always(function () {
isReady.resolve();
});
}
else if (shouldReload) {
refreshList();
}
// Item List
}
// Item List
function handleViewDisposing() {
POSApp.db.OrderDetails.off("modified", handleOrderDetailsModification);
}
function handleOrderDetailsModification() {
shouldReload = true;
}
// Item List
dataSource = new DevExpress.data.DataSource({
store: POSApp.db.OrderDetails,
map: function (item) {
return new POSApp.OrderDetailViewModel(item);
},
expand: ["Item"],
sort: { field: "OrderDetailId", desc: false },
filter: ["OrderId", parseInt(id)]
});
POSApp.db.OrderDetails.on("modified", handleOrderDetailsModification);
var viewModel = {
grandTotal: ko.observable(total),
handleDelete: function () {
DevExpress.ui.dialog.confirm("Are you sure you want to delete this item?", "Delete item").then(function (result) {
if (result)
handleConfirmDelete();
});
},
handleConfirmDelete: function () {
POSApp.db.Orders.remove(id).done(function () {
if (viewInfo.canBack) {
POSApp.app.navigate("Orders", { target: "back" });
}
else {
POSApp.app.navigate("Blank", { target: "current" });
}
});
},
//Item List
refreshList: function () {
shouldReload = false;
dataSource.pageIndex(0);
dataSource.load();
},
//Item List
// Return
id: id,
order: order,
viewShown: handleViewShown,
isReady: isReady.promise(),
// Item List
dataSource: dataSourceObservable,
viewDisposing: handleViewDisposing,
// Item List
// Return
};
return viewModel;
};
order-detail.js
<div data-options="dxView : { name: 'OrderDetail', title: 'Order' } " >
<div data-bind="dxCommand: { onExecute: '#OrderEdit/{id}', direction: 'none', id: 'edit', title: 'Edit', icon: 'edit' }"></div>
<div data-bind="dxCommand: { onExecute: handleDelete, id: 'delete', title: 'Delete', icon: 'remove' }"></div>
<div data-options="dxContent : { targetPlaceholder: 'content' } " class="dx-detail-view dx-content-background" data-bind="dxDeferRendering: { showLoadIndicator: true, staggerItemSelector: 'dx-fieldset-header,.dx-field', animation: 'detail-item-rendered', renderWhen: isReady }" >
<div data-bind="dxScrollView: { }">
<div class="dx-fieldset">
<div class="dx-fieldset-header" data-bind="text: order.PhoneNumber"></div>
<div class="dx-field">
<div class="dx-field-label">Order id</div>
<div class="dx-field-value-static" data-bind="text: order.OrderId"></div>
</div>
<div class="dx-field">
<div class="dx-field-label">Phone number</div>
<div class="dx-field-value-static" data-bind="text: order.PhoneNumber"></div>
</div>
<div class="dx-field">
<div class="button-info" data-bind="dxButton: { text: 'Add Item', onClick: '#AddItem/{id}', icon: 'add', type: 'success' }"></div>
<!-- Item List -->
<div data-bind="dxList: { dataSource: dataSource, pullRefreshEnabled: true }">
<div data-bind="dxAction: '#OrderDetailDetails/{OrderDetailId}'" data-options="dxTemplate : { name: 'item' } ">
<!--<div class="list-item" data-bind="text: Item().ItemName"></div>
<div class="list-item" style="float:right;" data-bind="text: Amount"></div>-->
<div class="item-name" data-bind="text: Item().ItemName"></div>
<div class="item-amount" data-bind="text: Amount"></div>
<div class="clear-both"></div>
</div>
</div>
</div>
<div class="dx-field">
<div class="dx-field-label">Grand total</div>
<!--<div class="dx-field-value-static" data-bind="text: order.GrandTotal"></div>-->
<div class="dx-field-value-static" data-bind="text: grandTotal"></div>
</div>
</div>
<div data-options="dxContentPlaceholder : { name: 'view-footer', animation: 'none' } " ></div>
</div>
</div>
</div>
I've tried by using get element by class name and it still doesn't work.

I've tried by using get element by class name and it still doesn't work.
You shouldn't try to get the data from your view; it's already in your viewmodel!
This documentation page tells me you can get an array of items from your DataSource instance by calling the items method.
From your data source's map function and your text: Amount data-bind, I figured each item probably has an Amount property which holds an integer.
grandTotal can be a computed that adds these values together whenever dataSourceObservable changes:
grandTotal: ko.computed(function() {
var total = 0;
var currentDS = dataSourceObservable();
if (currentDS) {
var currentItems = currentDS.items();
total = currentItems.reduce(function(sum, item) {
return sum + item.Amount;
}, total);
}
return total;
});

Here, the source is a Knockout observable array and the dxList data source. A value of grand totals is stored in the 'total' variable which is a computed observable depending on 'source'. So, once 'source' is changed, 'total' is re-calculated as well.
var grandTotal = ko.observable(0);
dataSource = new DevExpress.data.DataSource({
// ...
onChanged: function () {
grandTotal(0);
var items = dataSource.items();
for (var i = 0; i < items.length; i++) {
grandTotal(grandTotal() + items[i].Amount());
}
}
});
return {
// ...
grandTotal: grandTotal
};