Can not push new data to knockoutjs? - javascript

I'm using knockoutjs to bind data and this is the first time I use knockoutjs, I have a list data show to table, when user scroll down to bottom, it's will be load more new data. Here is my code:
HTML:
<div data-bind="template: { name: 'product-template', foreach: listProduct }" id="data-list"></div>
<script type="text/html" id="product-template">
<table>
<tr>
<td data-bind="text:name"></td>
<td data-bind="text:description"></td>
</tr>
</table>
</script>
and JS here:
var product = {
get : function(pageNumber){
var self = this;
self.listProduct = ko.observableArray([]);
request.product(pageNumber, function(resp){
//response list data of product
//example: {"data":[{"name":"sony","desciption":"this is sony"},{"name": "toshiba","description": "this is toshiba"}]};
if(pageNumber>1){
self.listProduct.push(resp.data);
}else{
self.listProduct(resp.data);
}
})
}
}
and then I call function like this:
ko.applyBindings(new product.get(1), document.getElementById("data-list"));// it's success to bind data
and bind more data when I call scroll down to bottom event:
ko.applyBindings(new product.get(2), document.getElementById("data-list"));// I got error: Error You cannot apply bindings multiple times to the same element
There is any something wrong? thanks.

I think what you want to do is something like infinite scroll, so see the example, i think this will simplify what you doing.
var viewModel = {
items: ko.observableArray([]),
//this function always will be called when scroll event was trigered
scrolled: function(data, event) {
var elem = event.target;
if (elem.scrollTop > (elem.scrollHeight - elem.offsetHeight - 200)) {
getItems(20);
}
},
//you can use this like your page
maxId: 0
};
function getItems(cnt) {
//here you do the requst for the data
//create fake data to pass to echo service
for (var i = 0; i < cnt; i++) {
var id = viewModel.maxId++;
viewModel.items.push({
id: id,
name: "Name" + id
});
}
}
ko.applyBindings(viewModel);
getItems(20);
#main { height: 500px; width: 500px; overflow: scroll; }
#main div { background-color: #eee; margin: 5px; height: 100px; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<div>
<span data-bind="text: items().length"></span>
</div>
<div id="main" data-bind="foreach: items, event: { scroll: scrolled }">
<div data-bind="text: name"></div>
</div>

Related

id values turns always same from foreach in mvc view page

I am using mvc .net core for a project and I have a view page. I need some id values from this page for using them inside partial view. Because I am using those id values for foreign key in another table to post. From main page these values posts in database correctly. I always post 5 values and always 5 id there in database I saw when I checked. But when I click the accordion this id always turns first id from these 5 values. if I posted as 6,7,8,9,10 it just turns me 6 and it doesn't matter if I clicked the last one in the page or first one. But context and title always correct when I check it from database and from page.
I tried a few jquery code but they didn't work correctly. I need the correct id values when I click other accordions.
I would be glad for any kind of help. Thanks a lot.
Here is my code:
#model IEnumerable<match>
#{
ViewData["Title"] = "Home Page";
}
<head>
<script src="~/lib/jquery/dist/jquery.js"></script>
<script src="~/lib/jquery/dist/jquery.min.js"></script>
<script src="~/lib/jquery-validation/dist/jquery.validate.js"></script>
<script src="~/lib/jquery-validation/dist/jquery.validate.min.js"></script>
<script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.js"></script>
<script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.min.js"></script>
<style>
.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #ccc;
}
.panel {
padding: 0 18px;
display: none;
background-color: white;
overflow: hidden;
}
</style>
</head>
<body>
<h4>Title List:</h4>
<table class="table table-hover">
#foreach (var item in Model)
{
<tr class="yzt">
<td class="xyz" id="item_title" >
<button class="accordion" id="title" >#Html.DisplayFor(modelItem => item.title)</button>
<div class="panel">
<p id="modelId" hidden>#Html.DisplayFor(modelItem=>item.Id)</p>
<p>#Html.DisplayFor(modelItem => item.context)</p>
#await Html.PartialAsync("Create", item.Exams#*, Exams*#)
</div>
</td>
</tr>
}
</table>
<script>
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function () {
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.display === "block") {
panel.style.display = "none";
} else {
panel.style.display = "block";
}
});
}
//document.querySelectorAll('.accordion').forEach(link => this.addEventListener('click', myFunction))
//function myFunction() {
// document.getElementById("matchId").value = document.getElementById("modelId").innerHTML;
// console.log("value is" + document.getElementById("matchId").value);
//}
document.querySelectorAll('.panel').forEach(link => this.addEventListener('click', myFunction))
function myFunction() {
document.getElementById("matchId").value = document.getElementById("modelId").innerHTML;
console.log("value is" + document.getElementById("matchId").value);
}
//document.querySelectorAll(".accordion")
//document.getElementById("match_title").value = document.getElementById("title").innerHTML;
</script>
</body>
I recommend you to write like this:
<div class="panel" id=#item.Id onclick="test(#item.Id)">
function test(val){
alert(val);
}
Your code will create multiple having id "title" and multiple having id "modelId", and this is also the reason why you always get the id from the first item, what you write document.getElementById("modelId").innerHTML will always get the first dom element which id = "modelId"

I am trying to switch values in table cells using angularjs... can i use ngbind or ngmodel or something else?

I am trying to make a table cell clickable. When the cell is clicked it will switch the contents from one cell to another. I want to make a basic chess game out of this click action by eventually using angular.element to get the clicked elements and setting the second clicked square equal to the first clicked.html(). Is this possible in AngluarJs using a MEAN somehow?
My current code looks like this but the table cell isn't changing or doing anything when I click.
app.controller('ChessCtrl' , ['$http', '$scope', '$document', function
ChessCtrl($http, $scope, $document) {
var vm = this;
vm.test1 = angular.element(document.getElementById("A1"));
vm.test2 = "";
vm.test3 = "This is a test";
$scope.click = function() {
var temp = vm.test3;
vm.test2 = temp;
vm.test3 = "";
}
}]);
<div ng-Controller="ChessCtrl">
<div class="content">
<div class="left">
<table style="width: 75%">
<tr>
<td id="A1" ><a ng-bind="vm.test3" ng-click="click()"></a></td>
<td class="grey" ng-bind="vm.test2"><a ng-bind="vm.test2" ng-click="click()"></a>
</td>
<td>
</tr>
</table>
</div>
</div>
</div>
Obviously I am missing something but I have tried adding to a DB and pulling it back out. I have tried ng-model and ng-bind for holding the variables. I am just lost on if or how I can get the td to be clickable and also switch where what is clicked displays. Thanks!
NOTE: disregard test1 in this example... I was using that earlier for testing getting the HTML out of the element.
The HTML doesn't need the <a> tag. Simply set the CSS style to cursor: pointer.
Also the ng-bind directive isn't necessary, simply bind model to HTML with double brace {{ }} expressions.
The DEMO
angular.module("app",[])
.controller('ChessCtrl' , function () {
var vm = this;
vm.test2 = "♔";
vm.test3 = "test";
vm.switch = function() {
var temp = vm.test2;
vm.test2 = vm.test3;
vm.test3 = temp;
}
});
.red { background-color: red; }
.grey { background-color: grey; }
td {
width: 20%;
cursor: pointer;
font-size: 24pt;
}
<script src="//unpkg.com/angular/angular.js"></script>
<body ng-app="app" ng-controller="ChessCtrl as vm">
<table>
<tr>
<td class="red" ng-click="vm.switch()">{{vm.test3}}</td>
<td class="grey" ng-click="vm.switch()">{{vm.test2}}</td>
</tr>
</table>
</body>
Okay, I try to figure out one solution that might work for you too.
I am adding code snippet have a look:
Main challange, that you are facing is, ng-bind,
have a look to this article and find the sole purpose of ng-bind
https://www.w3schools.com/angular/ng_ng-bind.asp
<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<body>
<div ng-app="myApp" ng-controller="myCtrl">
<table style="width: 75%">
<tr>
<td id="td1" ><a ng-bind="link1" ng-click="clickMe()"></a></td>
<td id="td2" class="" ><a ng-bind="link2" ng-click="clickMeAgain()"></a>
</td>
<td>
</tr>
</table>
</div>
<script>
var clickMeIsClicked = false;
var clickMeAgainIsClicked = false;
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
$scope.link1 = 'Click me to show td2';
$scope.link2 = ' I always want to be visible, thanks td1';
$scope.count = 0;
$scope.myFunction = function() {
$scope.count++;
}
$scope.clickMe = function(){
if(!clickMeIsClicked){
$scope.link2 = 'Click me to show td2';
$scope.link1 = ' I always want to be visible, thanks td1';
clickMeIsClicked = true;
}
else{
$scope.link1 = 'Click me to show td2';
$scope.link2 = ' I always want to be visible, thanks td1';
clickMeIsClicked = false;
}
}
$scope.clickMeAgain = function(){
}
});
</script>
</body>
</html>

Filter elements in DOM based on data-attr with jQuery

I'm trying to filter these items with jQuery autocomplete according to their data-name, but I got stuck with it a bit. Generally, I want to start typing the text in the input field and remove items from DOM if they don't match. Any help is much appreciated.
Pen: https://codepen.io/anon/pen/aVGjay
$(function() {
var item = $(".item");
$.each(item, function(index, value) {
console.log($(value).attr("data-name"));
var everyItem = $(value).attr("data-name");
});
$("#my-input").autocomplete({
source: everyItem, //?
minLength: 1,
search: function(oEvent, oUi) {
// get current input value
var sValue = $(oEvent.target).val();
// init new search array
var aSearch = [];
// for each element in the main array
$(everyItem).each(function(iIndex, sElement) {
// if element starts with input value
if (sElement.substr(0, sValue.length) === sValue) {
// add element
aSearch.push(sElement);
}
});
// change search array
$(this).autocomplete("option", "source", aSearch);
}
});
});
.items {
width: 200px;
}
.item {
background-color: red;
margin-top: 2px;
}
<input type="text" placeholder="Filter items" id="my-input">
<div class="items">
<div class="item" data-name="one">one</div>
<div class="item" data-name="two">two</div>
<div class="item" data-name="three">three</div>
<div class="item" data-name="four">four</div>
</div>
It's a little odd to use autocomplete for this, as that's intended to build a filtered option list from a provided object or remote data source, not from DOM content.
You can build the functionality yourself by attaching an input event listener to the #my-input which in turn goes through the .item elements and uses a regular expression to filter ones with matching data-name attributes and displays them, something like this:
$(function() {
var $items = $(".item");
$('#my-input').on('input', function() {
var val = this.value;
$items.hide().filter(function() {
return new RegExp('^' + val, 'gi').test($(this).data('name'));
}).show();
});
});
.items {
width: 200px;
}
.item {
background-color: red;
margin-top: 2px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" placeholder="Filter items" id="my-input">
<div class="items">
<div class="item" data-name="one">one</div>
<div class="item" data-name="two">two</div>
<div class="item" data-name="three">three</div>
<div class="item" data-name="four">four</div>
</div>

JS add +10 then sort DIV

GOAL script returns 20,13,12,11
Hi I am trying to make these two operations into a single operation on Load.
when loaded the page returns 3,2,10,1
so I have added a button to trigger a +10 function.
which returns 13,12,20,11
Both these functions work independently, however i need the the entire thing to work together so that it returns 20,13,12,11 on load
I don't want any buttons>>>>
<script src="js/jquery-1.4.1.min.js"></script>
<!--CSS-->
<style type="text/css">
.box {
border: 1px solid #000;
padding: 2px;
margin: 2px;
}
</style>
<!--JAVASCRIPT-->
<!-- (A) ADDS +10 to div No-->
<script type='text/javascript'>
$(document).ready(function(){
$("#increase").click(function(event){
$("div.box").each(function(idx,elem){
$(this).text( parseInt($(this).text(),10) +10 );
});
return false;
});
});
</script>
<div id="containerSort">
<!-- (B) SORTS div -->
<script type='text/javascript'>
$(function(){
var $divs = $("div.box");
$( "#numBnt" ).one("load", function() {
console.log('loaded')
var numericallyOrderedDivs = $divs.sort(function (a, b) {
return $(a).find("h7").text() < $(b).find("h7").text();
});
$("#containerSort").html(numericallyOrderedDivs);
});
});
</script>
<!--HTML-->
<div class="box"><h7>1</h7></div>
<div class="box"><h7>2</h7></div>
<div class="box"><h7>3</h7></div>
<div class="box"><h7>10</h7></div>
<img src="http://myscot.com/ImagesMain/myscotLogoResp120.jpg" id="numBnt"/>
</div>
<button id="increase">+10</button>
window.addEventListener("load", function(){...}) how would I combine the 2 functions to the event listener?
There are 2 ways to solve your problem
Call button's click event on page load.
Create a function which will wrap everything and assign it as eventListener.
Note:
$(function(){}) is a short hand for $(document).ready() and its a bad practice to have multiple document.ready functions.
H7 is not a valid header tag as mentioned by #Niet the Dark Absol. Browser might consider it as a custom element and process similar to span tag. (This is just a guess).
Below code:
$("div.box").each(function(idx, elem) {
$(this).text(parseInt($(this).text(), 10) + 10);
});
this will make multiple DOM operation. Its bad practice to manipulate DOM in a loop.
Following is a sample code. Also I have updated your code a bit.
JSFiddle.
$(document).ready(function() {
$("#increase").trigger("click");
});
$("#increase").click(function() {
var valArr = getValues();
valArr = addNumber(valArr);
valArr = sortValues(valArr);
createAndRenderHTML(valArr, "#containerSort");
});
function getValues() {
var returnArray = [];
$("div.box").each(function(id, el) {
returnArray.push(parseInt($(el).text(), 10));
});
return returnArray;
}
function addNumber(arr) {
return arr.map(function(item) {
return parseInt(item, 10) + 10;
});
}
function sortValues(arr) {
return arr.sort(function(a, b) {
return a > b ? -1 : a < b ? 1 : 0
});
}
function createAndRenderHTML(arr, el) {
var _html = arr.map(function(item) {
return "<div class='box'> <h7>" + item + "</h7></div>"
}).join("");
$(el).html(_html);
}
.box {
border: 1px solid #000;
padding: 2px;
margin: 2px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.0/jquery.min.js"></script>
<div id="containerSort">
<!--HTML-->
<div class="box">
<h7>1</h7>
</div>
<div class="box">
<h7>2</h7>
</div>
<div class="box">
<h7>3</h7>
</div>
<div class="box">
<h7>10</h7>
</div>
<img src="http://myscot.com/ImagesMain/myscotLogoResp120.jpg" id="numBnt" />
</div>
<button id="increase">+10</button>

Knockoutjs: Invoking function of parent component from child component

Problem:
I'm trying to build a dashboard of widgets. Each widget will have a delete button on its header. When clicked on this button, corresponding widget have to disappear.
How I designed:
I have two knockout components.
my-widget-list:
VO will have an observableArray of widget objects.
my-widget:
VO will have details to display within the widget.
Note: For simplicity, I'm replacing the widget object with just numbers.
ko.components.register('my-widget-list', {
viewModel : function(params) {
var self = this;
self.values = ko.observableArray([10,20,30,40,50]);
self.deleteWidget = function(obj)
{
self.values.remove(obj);
}
},
template: {element: 'my-widget-list-template'}
});
ko.components.register('my-widget', {
viewModel : function(params) {
var self = this;
self.value = params.value;
},
template: {element: 'my-widget-template'}
});
ko.applyBindings({});
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<my-widget-list></my-widget-list>
<script id="my-widget-list-template" type="text/html">
<div data-bind="foreach:values">
<my-widget params="value: $data"></my-widget><br>
</div>
</script>
<script id="my-widget-template" type="text/html">
<span data-bind="text: value"></span>
<button data-bind="click: $parent.deleteWidget">Delete</button>
</script>
Now, I want to invoke my-widget-list's deleteWidget function when the button is clicked.
I have thought about
Passing the parent view model reference into the child
Passing the parent function in the params attribute of the child component as a callback
But I wish to know from experts what's the best way to achieve this.
JsFiddle Link
Thanks in advance
You can pass in the parent as a param to the child:
ko.components.register('my-widget-list', {
viewModel : function(params) {
var self = this;
self.values = ko.observableArray([10,20,30,40,50]);
self.deleteWidget = function(obj) {
self.values.remove(obj);
}
},
template: {element: 'my-widget-list-template'}
});
ko.components.register('my-widget', {
viewModel : function(params) {
var self = this;
self.value = params.value;
self.remove = function () {
params.parent.deleteWidget(self.value);
};
},
template: {element: 'my-widget-template'}
});
ko.applyBindings({});
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<my-widget-list></my-widget-list>
<script id="my-widget-list-template" type="text/html">
<div data-bind="foreach:values">
<my-widget params="value: $data, parent: $parent"></my-widget><br>
</div>
</script>
<script id="my-widget-template" type="text/html">
<span data-bind="text: value"></span>
<button data-bind="click: remove">Delete</button>
</script>
But I'm not sure if that is a good idea, as it needlessly couples the child to the parent.
I'd recommend implementing the "remove" button in the parent, i.e. in <my-widget-list>, this way the widget can exist without a widget-list (or in a differently structured one) while the widget-list is in control of its children.
Compare window managers: They work the same way. The window manager draws the frame and the minimize/maximize/close buttons, while the window contents is drawn by the respective child process. That logic makes sense in your scenario as well.
Alternative implementation with removeWidget control in the parent:
ko.components.register('my-widget-list', {
viewModel : function(params) {
var self = this;
self.values = ko.observableArray([10,20,30,40,50]);
self.deleteWidget = function(obj) {
self.values.remove(obj);
}
},
template: {element: 'my-widget-list-template'}
});
ko.components.register('my-widget', {
viewModel : function(params) {
var self = this;
self.value = params.value;
},
template: {element: 'my-widget-template'}
});
ko.applyBindings({});
.widget-container {
position: relative;
display: inline-block;
padding: 10px 5px 5px 5px;
margin: 0 5px 5px 0;
border: 1px solid silver;
border-radius: 2px;
min-width: 40px;
}
.widget-buttons {
position: absolute;
top: 2px;
right: 2px;
}
.widget-buttons > button {
font-size: 2px;
padding: 0;
height: 15px;
width: 15px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js"></script>
<my-widget-list></my-widget-list>
<script id="my-widget-list-template" type="text/html">
<div class="widget-list" data-bind="foreach:values">
<div class="widget-container">
<div class="widget-buttons">
<button data-bind="click: $parent.deleteWidget">X</button>
</div>
<my-widget params="value: $data"></my-widget>
</div>
</div>
</script>
<script id="my-widget-template" type="text/html">
<div class="widget">
<span data-bind="text: value"></span>
</div>
</script>

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