nodeList gives only last item with onClick - javascript

I have a JSON file which gives me every country, and I place these within <li> tags.
I want to loop through this list, and put a click event on every <li>, which it does. But no matter what I click on, I always get the last item in the list returned to me. What am I missing?
I want the item I'm clicking returned.
function lists() {
var items = document.querySelectorAll('#Countries>ul>li');
for (i = 0; i < items.length; i++) {
var item = items[i];
item.onclick = function() {
console.log(item);
}
}
}

You need to pass the item in the onclick function as a parameter. This is because the function inside the for loop will consider only the last item.
function lists() {
var items = document.querySelectorAll('#Countries>ul>li');
for (i = 0; i < items.length; i++) {
var item = items[i];
item.onclick = function(item) {
console.log(item);
}
}
}
You can also use let to isolate the scope:
function lists() {
let items = document.querySelectorAll('#Countries>ul>li');
for (let i = 0; i < items.length; i++) {
let item = items[i];
item.onclick = function() {
console.log(item);
}
}
}

Declare the variable with let in the for loop that will declare a block scope local variable. Try
for (let i = 0; i < items.length; i++) {

its a scoping issue, var is function scope.
you can use let from es6 to declare the variable, or another way is to use bind.
function lists() {
var items = document.querySelectorAll('#Countries>ul>li');
for (i = 0; i < items.length; i++) {
var item = items[i];
item.onclick = function() {
console.log(this);
}.bind(item);
}
}
lists();
<div id="Countries">
<ul>
<li>country1</li>
<li>country2</li>
</ul>
</div>

Related

Click in JS loop undefined

I have an interation loop on which I need to click on every element:
var spans = document.getElementsByClassName('span')
for (var i = 0; i < spans.length; i += 1) {
i.click(function() {
console.log("Clicked")
});
}
I get i.click is not a function error. ¿What am I missing?
Thanks!
i is the index, not the element. This is how you would fix your code:
var spans = document.getElementsByClassName('span')
for (var i = 0; i < spans.length; i += 1) {
spans[i].click(function() {
console.log("Clicked")
});
}
But 'click' also doesn't take a callback. This is how your code should look like in 2022:
const spans = document.getElementsByClassName('span')
for (const span of spans) {
span.click();
console.log("Clicked")
}

How to Change Color of Div within a for statement?

Inside my php while loop I output a div with id divborder, and class div-border
Inside that div i have another div with id title
<div id='divborder' class='div-border'>
<div id='Title'>This is Title</div> <br/> video elements
</div>
I have a JavaScript function that get called when the video ends
for (var i = 0; i < videos.length; i++) {
videos[i].addEventListener("ended", function(event)
{
var divBoader2 = document.getElementsByClassName("divborder")[3];
divBoader2.style.borderColor = "#b1ff99";
}
My Question is how do i change the border color of the div and the title of second div?
I can do it like this:
var divBoader2 = document.getElementsByClassName("divborder")[3];
divBoader2.style.borderColor = "#b1ff99";
which works but its not dynamic
Save the value of value at i in another variable declared with let
for (var i = 0; i < videos.length; i++) {
let index = i; //save the value as let so that its binding stays
videos[i].addEventListener("ended", function(event)
{
var divBoader = document.querySelectorAll("div-border")[index];
divBoader.style.borderColor = "#b1ff99";
}
}
Or if the video elements are within the div-border, then use closest
for (var i = 0; i < videos.length; i++) {
videos[i].addEventListener("ended", function(event)
{
var divBoader = event.currentTarget.closest(".div-border");
divBoader.style.borderColor = "#b1ff99";
}
}
A little less verbose code
[...videos].forEach( s => s.closest( ".div-border" ).style.color = "#b1ff99" )
Try this,
Give class name div-border instead of divborder
for (var i = 0; i < videos.length; i++) {
videos[i].addEventListener("ended", function(event)
{
var divBoader2 = document.getElementsByClassName("div-border")[3];
divBoader2.style.borderColor = "#b1ff99";
}
What you need is probably a videos[i].parentNode instead of document.getElementsByClassName("div-border")[3] (see https://developer.mozilla.org/en-US/docs/Web/API/Node/parentNode)

Setting onclick function to <li> element

I am trying to dynamically add onclick function to "li" tagged elements.
But the event does not fires.
Here is my code:
var arrSideNavButtons = [];
var sideNavLi = document.getElementsByClassName('side-nav')[0].getElementsByTagName('li');
var arrayOfSceneAudios = [scene1Audio, scene2Audio,...];
for (var i = 0; i < sideNavLi.length; i++) {
sideNavLi[i].onclick = function() {
arrayOfSceneAudios[i].play();
}
arrSideNavButtons.push(sideNavLi[i]);
}
Is it possible to code it this way?
If yes, what is my mistake?
Thanks a lot.
Wrap your onclick handler in a closure, else it only get assigned to the last elem in the loop:
for (var i = 0; i < sideNavLi.length; i++) {
(function(i) {
sideNavLi[i].onclick = function() {
arrayOfSceneAudios[i].play();
}
arrSideNavButtons.push(sideNavLi[i]);
})(i)
}
I think it's better to reuse one single function, instead of creating a new one at each iteration:
var arrSideNavButtons = [],
sideNavLi = document.getElementsByClassName('side-nav')[0].getElementsByTagName('li'),
arrayOfSceneAudios = [scene1Audio, scene2Audio,...],
handler = function() {
this.sceneAudio.play();
};
for (var i = 0; i < sideNavLi.length; i++) {
sideNavLi[i].sceneAudio = arrayOfSceneAudios[i];
sideNavLi[i].onclick = handler;
arrSideNavButtons.push(sideNavLi[i]);
}

Changing classes in a menu with Javascript

I am looking to create a very simple functionality of clicking on a menu tab and it changes color to let you know what page you are on. I am a novice so please take it easy on me...lol
/Menu in php header file/
<ul class="tabs" id="tabs">
<li class="selected">Home</li>
<li class="inactive">Bio</li>
<li class="inactive">Photo</li>
<li class="inactive">Thank</li>
<li class="inactive">Contact</li>
</ul>
/*This is the JavaScript file*/
window.onload = initPage;
function initPage() {
var tabs = document.getElementById("tabs").getElementsByTagName("li");
for (var i=0; i<tabs.length; i++){
var links = tabs[i];
links.onclick = tabClicked;
}
}
function tabClicked(){
var tabId = this.id;
document.getElementById(tabId).classList.toggle("selected");
var tabs = document.getElementById("tabs").getElementsByTagName("li");
for (var i=0; i < tabs.length; i++){
var currentTab = tabs[i];
if (currentTab.id !== tabId){
currentTab.class = "selected";
} else {
currentTab.class = "inactive";
}
}
}
element.setAttribute("class", "className");
You are using ids in your code but you don't have provided it in your markup. so give ids to li elements and try this.
function tabClicked(){
var tabId = this.id;
document.getElementById(tabId).classList.toggle("selected");
var tabs = document.getElementById("tabs").getElementsByTagName("li");
for (var i=0; i < tabs.length; i++){
var currentTab = tabs[i];
if (currentTab.id !== tabId){
currentTab.className = "inactive";
} else {
currentTab.className= "selected";
}
}
}
JS Fiddle Demo
Store a reference to each of the list items.
Create a variable to keep track of the current tab.
In an onclick function for each element (or you could use one onclick and just use some conditions), change the class attribute of the element by using the setAttribute() method.
Like this:
function onFirstTabClick() {
clearSelected();
tabVariable1.setAttribute("class","some-new-class");
}
function() clearSelected() {
switch(currentSelectedTrackerVariable) {
case 1: tabVariable1.setAttribute("class","some-new-class");
break;
// Do this for the amount of tabs that you have.
}
}
Working FIDDLE Demo
There is no need to define functions globally. Write all them in one package. The code below, works correctly with your HTML markup.
<script>
window.onload = function () {
var tab = document.getElementById('tabs');
var lis = tab.getElementsByTagName('li');
for (var i = 0, l = lis.length; i < l; i++) {
lis[i].onclick = function () {
for (var j = 0; j < l; j++) {
lis[j]["className"] = "inactive";
}
this["className"] = "selected";
};
}
};
</script>
If you use jQuery, then tabClicked can run:
jQuery('.selected').removeClass('selected').addClass('inactive');
jQuery(this).removeClass('inactive').addClass('selected');

return or send variable to onchange event

I am trying to achieve the same functionality of a function from two separate events. So the function I created is:
function adding_stuff() {
var names = [];
var dates = [];
for(var i = 0; i < this.files.length; i++) {
//adding stuff to names and dates
}
$(".primary .panel-content").append("<ul class='list-unstyled'></ul>");
for(var i in names) {
var li = "<li>";
$(".primary .panel-content ul").append(li.concat(names[i]))
}
}
There are two buttons primary and secondary. I want the same functionality for both the functions but the output in different <div>. Currently the selected <div> is ".primary", however I want this to depend on the button which has been clicked.
The function is triggered using:
$("#primary").onchange = adding_stuff;
$("#secondary").onchange = adding_stuff;
NOTE: primary and secondary are inputs of type file.
You can add additional data when you register the callback, which will be made available within the event handler:
$('#primary').on('change', { target: '.primary' }, adding_stuff);
$('#secondary').on('change', { target: '.secondary' }, adding_stuff);
and then within the handler:
function adding_stuff(ev) {
var cls = ev.data.target; // extract the passed data
...
// file handling code omitted
$(".panel-content", cls).append(...)
}
using jquery's change() event
function adding_stuff(obj,objClass) {
var names = [];
var dates = [];
for(var i = 0; i < obj.files.length; i++) {
//adding stuff to names and dates
}
$("."+ objClass+" .panel-content").append("<ul class='list-unstyled'></ul>");
for(var i in names) {
var li = "<li>";
$("."+ objClass+" .panel-content ul").append(li.concat(names[i]))
}
}
$("#primary").change(function(){
adding_stuff(this,'primary');
});
$("#secondary").change(function(){
adding_stuff(this,'secondary');
});
Try
function adding_stuff(opselector) {
return function() {
var names = [];
var dates = [];
for (var i = 0; i < this.files.length; i++) {
// adding stuff to names and dates
}
var ul = $("<ul class='list-unstyled'></ul>").appendTo(opselector)
for (var i in names) {
ul.append("<li>" + li.concat(names[i]) + "</li>")
}
}
}
$("#primary").change(adding_stuff('.primary .panel-content'));
$("#secondary").change(adding_stuff('.secondary .panel-content'));
You can use $(this).attr("class") inside the function. It will return the class of button who triggered the event.
function adding_stuff() {
var div = $(this).attr("class");
var names = [];
var dates = [];
for(var i = 0; i < this.files.length; i++) {
//adding stuff to names and dates to $div
}
$(div + " .panel-content").append("<ul class='list-unstyled'></ul>");
for(var i in names) {
var li = "<li>";
$(div + " .panel-content ul").append(li.concat(names[i]));
}
}

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