Develop Reference

Remove or Active a certain state when clicking on a div element with pure JavaScript

the past few days I submitted a question about a pagination (how to add and remove an active state in css using pure JavaScript), And I got a great answer. And some what in the same problem i m having an issue removing an active state only this time when clicking on another div.
let questions = document.querySelectorAll('.question__container'),
questionBar = document.querySelectorAll('#bar'),
questionClose = document.querySelectorAll('.paragraph__close'),
answers = document.querySelectorAll('.answers__container');
/* activeBar / activeAnswer */
function resetQuestions() {
for (let i = 0; i < questions.length; i++) {
questionBar[i].classList.remove('activeBar');
answers[i].classList.remove('activeAnswer');
}
}
function addActiveAnswer() {
for (let i = 0; i < questions.length; i++) {
questions[i].addEventListener('click', function() {
resetQuestions();
questionBar[i].classList.add('activeBar');
answers[i].classList.add('activeAnswer');
questionClose[i].addEventListener('click', function() {
resetQuestions();
});
});
}
}
addActiveAnswer();
I m trying to build whats called a Q&A page, when a user clicks over a question, an answer fades in underneath, But when clicking the closing div element, the resetQuestions(); doesn't get executed.
Thank you in advance for any answer.

If Previous Content Div is Open, Close It and Open the Next (Plain JavaScript)

I have this simple dropdown faq system, I only want one content div to be open at a time, so I tried to use an if / else condition, but I can only make it work halfway.
I'm checking if the content div next to the trigger div has class is-visible — if not, add that class (this works)
But if the previous content div has (contains) class is-visible, I want to remove it, so only one content div is open at a time.
I've tried so many different conditions but I think I'm overcomplexifying it, this should be simple enough right?
https://jsfiddle.net/notuhm05/1/
var faqTrigger = document.querySelectorAll('.mm-faq-trigger');
for (var i = 0; i < faqTrigger.length; i++) {
faqTrigger[i].addEventListener('click', function() {
if (!this.nextElementSibling.classList.contains('is-visible')) {
this.nextElementSibling.classList.add('is-visible');
} else if (this.previousElementSibling.classList.contains('is-visible')) {
this.nextElementSibling.classList.remove('is-visible');
} else {
console.log("doesn't work");
}
});
}
Would greatly appreciate some pointers here! :-)

Here is a working solution:
Toggle the class is-visible on the clicked node
Iterate through all triggers and remove the class is-visible if the id of the href tag does not match the clicked nodes id. NOTE: I had to add an id property to the trigger href tag like <a id="1" href="#" class="mm-faq-trigger">Trigger</a>
Source Code:
var faqTrigger = document.querySelectorAll('.mm-faq-trigger');
for (var i = 0; i < faqTrigger.length; i++) {
faqTrigger[i].addEventListener('click', function() {
this.nextElementSibling.classList.toggle('is-visible');
for (var i = 0; i < faqTrigger.length; i++) {
var trigger = faqTrigger[i];
if (trigger.nextElementSibling !== null && trigger.id !== this.id) {
trigger.nextElementSibling.classList.remove('is-visible');
}
}
});
}

How to remove all classes except the one you clicked?

This functions starts when I click on a link. It needs to remove all '.is-active' classes on the elements with the attribute [data-route]. And add the class '.is-active' on the [data-route] element that is connected with the link I clicked on.
toggle: function(section){
var sections = document.querySelectorAll('[data-route]');
for (i = 0; i < sections.length; i++){
document.querySelector('[data-route]').classList.remove('is-active');
}
document.querySelector(section).classList.add('is-active');
}
But this doesn't work. It doesn't remove the classes?
See example: http://jordypouw.github.io/myFED2/deeltoets1/index.html
P.S. it has to be in vanilla JavaScript.

toggle: function(section){
var sections = document.querySelectorAll('[data-route]');
for (i = 0; i < sections.length; i++){
sections[i].classList.remove('is-active');
// querySelectorAll return an array of dom elements, u can access them directly.
}
// I suppose in your case that ' section ' variable is the clicked element so :
section.classList.add('is-active')
// if not you have to store the dom element from the event, and add the class here.
}

you can do this:
for (var item of document.querySelectorAll('[data-route]')) {
item.classList.remove('is-active');
}
This is ecmascript6 so it won't work on old browsers. I like it because it's clean and nice. to get it to work on other browsers you must convert the nodes collection into a real array, so you could loop it.

toggle: function(section){
document.querySelectorAll("[data-route]").forEach( e => {
e.classList.remove("is-active");
});
// querySelectorAll return an array of dom elements, u can access them directly.
// I suppose in your case that ' section ' variable is the clicked element so :
document.querySelectorAll("[data-route]").forEach( e => {
e.classList.add("is-active");
});
// if not you have to store the dom element from the event, and add the class here.
}

Set up a variable for the clicked item..
jQuery('.clicker-item').on("click", function(){
var clicked = jQuery('.clicker-item').not(jQuery(this));
clicked.removeClass("active")
jQuery(this).toggleClass("active")
});

I felt, that other answers were not neat enough.
toggle: (s) => {
// Find all other sections and remove the active class:
document.body.querySelectorAll('[data-route]').forEach(i => i.classList.remove('is-active'))
// Add active to the inputted section:
s.classList.add('is-active')
}

shouldn't it be this:
toggle: function(section){
var sections = document.querySelectorAll('[data-route]');
for (i = 0; i < sections.length; i++){
document.querySelector('[data-route]').removeClass('is-active');
}
document.querySelector(section).addClass('is-active');
}
Edit: Sorry, I should have said removeClass and addClass

How do I filter an unorderded list to display only selected items using Javascript?

I have this JSFiddle where I am trying to make it so that the items in an unordered list are visible only if the option selected in a drop down matches their class. List items may have multiple classes, but so long as at least one class matches, the item should be made visible.
The Javascript looks like this:
function showListCategories() {
var selection = document.getElementById("listDisplayer").selectedIndex;
var unHidden = document.getElementsByClassName(selection);
for (var i = 0; i < unHidden.length; i++) {
unHidden[i].style.display = 'visible';
}
};
The idea is that it gets the current selection from the drop down, creates an array based on the matching classes, then cycles through each item and sets the CSS to be hidden on each one.
However, it's not working. Can anyone tell me where I'm going wroing?
Note that I haven't yet coded the "show all" option. I think I'll probably be able to figure that out once I have this first problem solved.

In your fiddle change load script No wrap - in <head>.
Just change your function like following
function showListCategories() {
var lis = document.getElementsByTagName('li');
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'none';
}
//above code to reset all lis if they are already shown
var selection = document.getElementById("listDisplayer").value;
lis = document.getElementsByClassName(selection);
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'block';
}
};
and in css it should be none not hidden
.cats, .rats, .bats {
display: none;
}
If you want to show all li when showAll is selected, add all classes to all lis.

You have a few things going on. First, your fiddle is not setup correctly, if you open the console you'll see:
Uncaught ReferenceError: showListCategories is not defined
This means that the function doesn't exist at the point you attach the event or that the function is out of scope, because by default jsFiddle will wrap your code in the onLoad event. To fix it you need to load the script as No wrap - in <body>.
Second, there's no such thing as a display:visible property in CSS. The property you want to toggle is display:none and display:list-item, as this is the default style of <li> elements.
Now, to make this work, it is easier if you add a common class to all items, let's say item, that way you can hide them all, and just show the one you want by checking if it has a certain class, as opposed to querying the DOM many times. You should cache your selectors, it is not necessary to query every time you call the function:
var select = document.getElementById('listDisplayer');
var items = document.getElementsByClassName('item');
function showListCategories() {
var selection = select.options[select.selectedIndex].value;
for (var i=0; i<items.length; i++) {
if (items[i].className.indexOf(selection) > -1) {
items[i].style.display = 'list-item';
} else {
items[i].style.display = 'none';
}
}
}
Demo: http://jsfiddle.net/E2DKh/28/

First there is no property in Css like display:hidden; it should be display: none;
here is the solution please not that i am doing it by targeting id finished
Js function
var selection = document.getElementById("listDisplayer");
var list = document.getElementsByTagName('li');
selection.onchange = function () {
var value = selection.options[selection.selectedIndex].value; // to get Value
for (var i = 0; i < list.length; i++) {
if (list[i].className.indexOf(value) > -1) {
list[i].style.display = "list-item";
} else {
list[i].style.display = "none"
}
}
}
css Code
.cats, .rats, .bats {
display: none;
}
JSFIDDLE

You have many things wrong in your code and a wrong setting in the jsFiddle. Here's a working version that also implements the "all" option:
Working demo: http://jsfiddle.net/jfriend00/5Efc5/
function applyToList(list, fn) {
for (var i = 0; i < list.length; i++) {
fn(list[i], list);
}
}
function hide(list) {
applyToList(list, function(item) {
item.style.display = "none";
});
}
function show(list) {
applyToList(list, function(item) {
item.style.display = "block";
});
}
function showListCategories() {
var value = document.getElementById("listDisplayer").value;
var itemList = document.getElementById("itemList");
var items = itemList.getElementsByTagName("li");
if (value === "all") {
show(items);
} else {
// hide all items by default
hide(items);
show(itemList.getElementsByClassName(value));
}
}
Changes made:
You have to fetch the .value of the select to see what the value was of the option that was picked. You were using the selectedIndex which is just a number.
A common technique for displaying only a set of objects is to hide all of them, then show just the ones you want. Since the browser only does one repaint for the entire operation, this is still visually seamless.
When finding items that match your class, you should be searching only the <ul>, not the entire document. I added an id to that <ul> tag so it can be found and then searched.
To save code, I added some utility functions for operating on an HTMLCollection or nodeList.
Tests for the "all" option and shows them all if that is selected
Changed the jsFiddle to the Head option so the code is available in the global scope so the HTML can find your change handler function.
Switched style settings to "block" and "none" since "visible" is not a valid setting for style.display.

AJAX: Applying effect to CSS class

I have a snippet of code that applies a highlighting effect to list items in a menu (due to the fact that the menu items are just POST), to give users feedback. I have created a second step to the menu and would like to apply it to any element with a class of .highlight. Can't get it to work though, here's my current code:
[deleted old code]
The obvious work-around is to create a new id (say, '#highlighter2) and just copy and paste the code. But I'm curious if there's a more efficient way to apply the effect to a class instead of ID?
UPDATE (here is my updated code):
The script above DOES work on the first ul. The second ul, which appears via jquery (perhaps that's the issue, it's initially set to hidden). Here's relevant HTML (sort of a lot to understand, but note the hidden second div. I think this might be the culprit. Like I said, first list works flawlessly, highlights and all. But the second list does nothing.)?
//Do something when the DOM is ready:
<script type="text/javascript">
$(document).ready(function() {
$('#foo li, #foo2 li').click(function() {
// do ajax stuff
$(this).siblings('li').removeClass('highlight');
$(this).addClass('highlight');
});
//When a link in div is clicked, do something:
$('#selectCompany a').click(function() {
//Fade in second box:
//Get id from clicked link:
var id = $(this).attr('id');
$.ajax({
type: 'POST',
url: 'getFileInfo.php',
data: {'id': id},
success: function(msg){
//everything echoed in your PHP-File will be in the 'msg' variable:
$('#selectCompanyUser').html(msg)
$('#selectCompanyUser').fadeIn(400);
}
});
});
});
</script>
<div id="selectCompany" class="panelNormal">
<ul id="foo">
<?
// see if any rows were returned
if (mysql_num_rows($membersresult) > 0) {
// yes
// print them one after another
while($row = mysql_fetch_object($membersresult)) {
echo "<li>"."".$row->company.""."</li>";
}
}
else {
// no
// print status message
echo "No rows found!";
}
// free result set memory
mysql_free_result($membersresult);
// close connection
mysql_close($link);
?>
</ul>
</div>
<!-- Second Box: initially hidden with CSS "display: none;" -->
<div id="selectCompanyUser" class="panelNormal" style="display: none;">
<div class="splitter"></div>
</div>

You could just create #highlighter2 and make your code block into a function that takes the ID value and then just call it twice:
function hookupHighlight(id) {
var context = document.getElementById(id);
var items = context.getElementsByTagName('li');
for (var i = 0; i < items.length; i++) {
items[i].addEventListener('click', function() {
// do AJAX stuff
// remove the "highlight" class from all list items
for (var j = 0; j < items.length; j++) {
var classname = items[j].className;
items[j].className = classname.replace(/\bhighlight\b/i, '');
}
// set the "highlight" class on the clicked item
this.className += ' highlight';
}, false);
}
}
hookupHighlight("highliter1");
hookupHighlight("highliter2");
jQuery would make this easier in a lot of ways as that entire block would collapse to this:
$("#highlighter1 li, #highlighter2 li").click(function() {
// do ajax stuff
$(this).siblings('li').removeClass('highlight');
$(this).addClass('highlight');
});
If any of the objects you want to click on are not initially present when you run this jQuery code, then you would have to use this instead:
$("#highlighter1 li, #highlighter2 li").live("click", function() {
// do ajax stuff
$(this).siblings('li').removeClass('highlight');
$(this).addClass('highlight');
});

change the replace in /highlight/ig, it works on http://jsfiddle.net/8RArn/
var context = document.getElementById('highlighter');
var items = context.getElementsByTagName('li');
for (var i = 0; i < items.length; i++) {
items[i].addEventListener('click', function() {
// do AJAX stuff
// remove the "highlight" class from all list items
for (var j = 0; j < items.length; j++) {
var classname = items[j].className;
items[j].className = classname.replace(/highlight/ig, '');
}
// set the "highlight" class on the clicked item
this.className += ' highlight';
}, false);
}

So all those guys that are saying just use jQuery are handing out bad advice. It might be a quick fix for now, but its no replacement for actually learning Javascript.
There is a very powerful feature in Javascript called closures that will solve this problem for you in a jiffy:
var addTheListeners = function (its) {
var itemPtr;
var listener = function () {
// do AJAX stuff
// just need to visit one item now
if (itemPtr) {
var classname = itemPtr.className;
itemPtr.className = classname.replace(/\bhighlight\b/i, '');
}
// set the "highlight" class on the clicked item
this.className += ' highlight';
itemPtr = this;
}
for (var i = 0; i < its.length; i++) {
its[i].addEventListener ('click', listener, false);
}
}
and then:
var context = document.getElementById ('highlighter');
var items = context.getElementsByTagName ('li');
addTheListeners (items);
And you can call add the listeners for distinct sets of doc elements as many times as you want.
addTheListeners works by defining one var to store the list's currently selected item each time it is called and then all of the listener functions defined below it have shared access to this variable even after addTheListeners has returned (this is the closure part).
This code is also much more efficient than yours for two reasons:
You no longer iterate through all the items just to remove a class from one of them
You aren't defining functions inside of a for loop (you should never do this, not only for efficiency reasons but one day you are going to be tempted to use that i variable and its going to cause you some problems because of the closures thing I mentioned above)