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Using only JS and css, can I implement a filter, so that: clicking/tapping within a JS dropdown menu shows/hides page divs by data-type?

With the help of SO member the.marolie I learned how to implement a JS filter/selector [the 'demo JS filter']. I have this working perfectly on a test page: it shows/hides divs according to "data-types" assigned to them in the body html. However, the selection is made by sliding down a <select> dropdown list and letting go at the preferred option. That's not quite what I want.
I want to utilise my existing nav-bar dropdown ['my dropdown'] as the filter/selector. I especially want to retain the existing interactivity of my dropdown, whereby one click/tap reveals the whole of the dropdown content block, and one click outside the content block closes it.
I want the elements within my dropdown to represent various show/hide <div> 'options' for the html page, and enable the user to choose from these via an additional click/tap (essentially what the demo JS filter does, but at the instigation of a click/tap). Once revealed via a nav-bar click/tap, the whole dropdown content block has to stay on-screen -as it currently does- for this to be practically possible.
After making my dropdown identifiable via id="media-selector-demo" and name="filter" I was hoping that I could assign the demo JS filter's <option> elements to the <a> elements in it, and the whole thing would function like the <select> dropdown of the demo JS filter. I had a vague idea that using <a> elements might obviate the need for another onClick in the JS. I've tried various combinations of <a> and <option> elements, but nothing has worked yet.
Do I need another onClick to invoke the JS filter via my dropdown? or
Can I invoke the JS filter via 'active' <a> status?
I'm struggling by trial and error.
Here are what I think are the relevant sections of code pertaining to all discussed above:
My dropdown is based on the following code.
JS in the page head:
/* When the user clicks on the button,
toggle between hiding and showing the dropdown content */
function myDropdownJS() {
document.getElementsByClassName("navbarDROPDOWN-JS")[0].classList.toggle("show");
}
// Close the dropdown if the user clicks outside of it
window.onclick = function(e) {
if (!e.target.matches('.dropbtn')) {
var myDropdown = document.getElementsByClassName("navbarDROPDOWN-JS")[0];
if (myDropdown.classList.contains('show')) {
myDropdown.classList.remove('show');
}
}
}
My dropdown html in nav bar (most of the css is just design styling):
<span class="dropdown" onclick="myFunction()">
<a class="dropbtn navbarDROP-ICON" style="opacity:0.5; padding-top:0px;">menu</a>
<a class="dropbtn navbarDROP-TXT" style="opacity:0.5">menu </a>
<a class="dropbtn navbarDROP-TXT">Career Works by Date </a>
<div class="dropdown-content navbarDROPDOWN-JS" >
<a class="tag-bgd-INSTLLN" href="#">Installations (all media)</a>
<a class="tag-bgd-MOVIMG" href="#">Works with moving image (inc. vid/film releases)</a>
<a class="tag-bgd-SNDMUS" href="#">...with sound and music (inc. sound/music releases)</a>
<a class="tag-bgd-PHOTO" href="#">...with photographs</a>
<a class="tag-bgd-DRAW" href="#">...with drawing (inc. 2D works)</a>
<a class="tag-bgd-TXT" href="#">...with text</a>
<a class="tag-bgd-PERF" href="#">...with performative action</a>
<a class="tag-bgd-COLPUB" href="#">Collaborative and public works</a>
<a class="tag-bgd-OBJDEV" href="#">>Objects, garments, devices</a>
<a class="tag-bgd-EDPUB" href="#">Editions, publications</a>
<a class="tag-bgd-CAREER" href="#">Career Works by Date</a>
</div>
Above: the <a href> elements were going to contain URLs for alternatively styled pages. There is no need for these if I can enable the user to selectively show/hide parts of just this one page, via this dropdown.
The demo JS filter is based on the following code (via SO user the.marolie).
JS at page end:
var select = document.getElementById('media-selector-demo');
var filter;
select.addEventListener("change", function() {
filter = select.value;
var elements = document.querySelectorAll('.wk-date_ITEM');
elements.forEach((el) => {
var type = el.dataset.type.split(', ');
if (type.includes(filter)) {
el.classList.remove('hide-by-media');
} else {
el.classList.add('hide-by-media');
}
})
});
Demo JS filter CSS:
.hide-by-media {
display: none;
}
Demo JS filter html in page body:
<select id="media-selector-demo" name="filter">
<option value="INSTLLN"> Installations (all media)</option>
<option value="MOVIMG"> Works with moving image (inc. vid/film releases)</option>
<option value="SNDMUS" >...with sound and music (inc. sound/music releases)</option>
</select>
Example div in page body (there are 80-100 of these):
<!-- ++++++++++ START FULL-WIDTH LIST ENTRY '2017 STATE OF DREAD' ++++++++++ -->
<div id="state-of-dread" class="w3-container wk-date_ITEM" data-type="INSTLLN, SNDMUS">
<div class="w3-container wk-date_TXT-IMG">
<div class="wk-date_GRID">
<div class= "h3 wk-date_DATE"> 2017 </div>
<div class="wk-date_TTL"><h1>State of Dread</h1></div>
<div class="h2 wk-date_KIND-1" >Installation</div>
<div class="p wk-date_KIND-2" ><span class="sound">Sound</span>, for x2 interconnected rooms.<br>AB, CD, EF, Solo exhibition (as trio), Ohrenhoch sound gallery, Berlin.</div>
<div class="wk-date_IMG">
<div class="w3-container w3-right wk-date_IMG-BOX-LSCP">
<img src="../../imgs/INSTALLATION-EVENT/2017_dread_thmb.jpg"
alt="'xx' by Andrew Stones, installation view, xx"></div>
</div>
</div>
</div>
</div>
<!-- ++++++++++ END FULL-WIDTH LIST ENTRY '2017 STATE OF DREAD' ++++++++++ -->
Demo JS filter: JS at end of page:
<script type="text/javascript">
var select = document.getElementById('media-selector-demo');
var filter;
select.addEventListener("change", function() {
filter = select.value;
var elements = document.querySelectorAll('.wk-date_ITEM');
elements.forEach((el) => {
var type = el.dataset.type.split(', ');
if (type.includes(filter)) {
el.classList.remove('hide-by-media');
} else {
el.classList.add('hide-by-media');
}
})
});
</script>

What you would need to do is change the event listener from select, change to drop down element, click. you would also need to add the values of the options from the select as data-value attributes on the drop down elements.
1 - add a data-value attribute to the elements to represent what to hide
<a class="tag-bgd-INSTLLN" href="#" data-value="INSTLLN">
2 - target the drop down elements you want to attach the event listener to.
const dropDownElements = document.querySelectorAll('.dropdown-content a')
3 - attach event listeners to the selected targets (PS. the e in the function stands for event, click event listener produces an event object)
dropDownElements.forEach((dropDownElement) => {
dropDownElement.addEventListener('click',(e)=>{
const filter = e.target.dataset.value;
})
})
4 - the rest is just adding the rest of the filter used in the demo js filter
dropDownElements.forEach((dropDownElement) => {
dropDownElement.addEventListener("click", (e) => {
const filter = e.target.dataset.value
var elements = document.querySelectorAll(".wk-date_ITEM")
elements.forEach((el) => {
var type = el.dataset.type.split(", ")
if (type.includes(filter)) {
el.classList.remove("hide-by-media")
} else {
el.classList.add("hide-by-media")
}
})
})
})

Blazor - Prevent sibling event from firing ( onclick > onfocusout )

I'm creating my own autocomplete input in Blazor. (something like below)
function FocusOut()
{
document.getElementById("list-item-one").innerHTML = "Focus out";
}
function Click()
{
document.getElementById("list-item-one").innerHTML = "Click";
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="search" onfocusout="FocusOut()" />
<ul class="dropdown">
<li id="list-item-one" onclick="Click()">List Item One</li>
</ul>
When I click on the list item, the onfocusout event fires instead of the onclick event. Is there a way to "push" the onclick event?
This isn't a parent child relation, so "stopPropagation" has no effect. Also I know there is a datalist tag, but i'm not using it because of the way it look, feels and behaves in the different browsers.

The problem is that the order of events is OnMouseDown, OnFocusOut, OnClick.
Because of this, your dropdown closes before the OnClick event, so the click is not registered.
A working solution is to replace OnClick with OnMouseDown.
Based on this answer by #DuncanLuk.

I had a similar issue and I added a await Task.Delay(250) in my #onfocusout handler and it worked. You can find the live demo by clicking three vertical dots at top right in ilovedotnet site.
<section id="social">
<div class="dropdown is-right #(MenuCollapsed ? null : "is-active")" #onclick="ToggleMenu" #onfocusout="FocusOutHandler">
<div class="dropdown-trigger">
<button class="button" aria-haspopup="true" aria-controls="social-menu">
Social
</button>
</div>
<div class="dropdown-menu" id="social-menu" role="menu">
<div class="dropdown-content">
<a href="https://ilovedotnet.org/" target="_blank" class="dropdown-item">
I Love DotNet
</a>
</div>
</div>
</div>
</section>
#code {
internal bool MenuCollapsed { get; private set; } = true;
internal void ToggleMenu()
{
MenuCollapsed = !MenuCollapsed;
}
internal async Task FocusOutHandler()
{
// to avoid race between mouse click of anchor tag Navigation. without this delay Navigation
// is not getting executed when item is clicked from mouse
await Task.Delay(250);
MenuCollapsed = true;
}
}

MDC Web: mdc-select update hidden input value on change (non-native select box) | JavaScript (JS)

Been doing well so far with MDC Web Components, but I've been hung up here for far too long. (Not strong in JS.)
mdc-select used to be non-native, then used native HTML select, and now once again it's non-native. For a while MDC Web supported a hidden input so that you could pass values to the server.
There's hardly any documentation - mostly just stuck users like me opening issues on GitHub:
Closed: MDC Select - no longer form input compatible #2221
Closed: [MDC Select] Example in README does send values to the web server #5295
Open: [MDCSelect] Add hidden input element to support HTML forms #5428
I need to set/update the value of a hidden input on MDCSelect change for multiple select boxes on the same page... I can get it to do it for ONE select box, but not multiple.
Here is the select box HTML:
<div class="mdc-select mdc-select--outlined region-select">
<div class="mdc-select__anchor demo-width-class">
<i class="mdc-select__dropdown-icon"></i>
<div id="demo-selected-text" class="mdc-select__selected-text" tabindex="0" aria-disabled="false" aria-expanded="false"></div>
<div class="mdc-notched-outline">
<div class="mdc-notched-outline__leading"></div>
<div class="mdc-notched-outline__notch" style="">
<label id="outlined-label" class="mdc-floating-label" style="">Region</label>
</div>
<div class="mdc-notched-outline__trailing"></div>
</div>
</div>
<div class="mdc-select__menu mdc-menu mdc-menu-surface demo-width-class">
<ul class="mdc-list">
<li data-value="" disabled="" aria-selected="false" role="option" class="mdc-list-item" tabindex="0"></li>
<li data-value="north" aria-selected="false" role="option" class="mdc-list-item" tabindex="-1">North</li>
<li data-value="east" aria-selected="false" role="option" class="mdc-list-item" tabindex="-1">East</li>
<li data-value="south" aria-selected="false" role="option" class="mdc-list-item" tabindex="-1">South</li>
<li data-value="west" aria-selected="false" role="option" class="mdc-list-item" tabindex="-1">West</li>
</ul>
</div>
<!-- THIS IS THE HIDDEN INPUT THANK YOU -->
<input type="hidden" id="name2" name="input_name2" value="" class="my_mdc-select__value" />
</div>
I've tried targeting the hidden input with id, name, and even class. I think I need some sort of integrated function, forEach, or loop - tried adding JS beneath each select with no avail. I've worked the examples (seen below) from other users and no success. JavaScript isn't my thing, I know what it supposed to be happening but don't know the function or loop syntax etc to make this work.
I need to make sure each set/update targets the correct hidden input associated with that particular select box.
Here is my JS that works for ONE select box but not multiple:
// Select Menu
import {MDCSelect} from '#material/select';
const selectElements = [].slice.call(document.querySelectorAll('.mdc-select'));
selectElements.forEach((selectEl) => {
const select = new MDCSelect(selectEl);
select.listen('MDCSelect:change', (el) => {
const elText = el.target.querySelector(`[data-value="${select.value}"]`).innerText;
console.log(`Selected option at index ${select.selectedIndex} with value "${select.value}" with a label of ${elText}`);
// this works but only saves one
document.querySelector('input.my_mdc-select__value').value = select.value;
});
});
Here is some code that others used that I haven't been able to modify/apply (taken from links above):
From nikolov-tmw:
document.querySelectorAll( '[data-mdc-auto-init="MDCSelect"]' ).forEach( function( sel ) {
sel.My_MDCSelect__Value = sel.querySelector('input.my_mdc-select__value');
if ( null !== sel.My_MDCSelect__Value ) {
sel.addEventListener( 'MDCSelect:change', function( a ) {
if ( sel.MDCSelect ) {
sel.My_MDCSelect__Value.value = sel.MDCSelect.value;
}
} );
}
} );
From daniel-dm:
<div class="mdc-select">
...
</div>
<input id="pet-select" type="hidden" name="pets">
<script>
const input = document.querySelector('#pet-select');
const select = document.querySelector('.mdc-select');
select.addEventListener('MDCSelect:change', e => {
input.value = e.detail.value;
});
</script>
Please help! This particular issue has been open since January (people struggling long before) with no clear solution to help non-JS developers implement MDCSelect boxes. Thanks in advance!

The problem is here:
document.querySelector('input.my_mdc-select__value').value = select.value;
Document.querySelector will find the first matching element in the whole document, so in your loop you're always accessing the same input element.
Instead, you should run querySelector method on the parent element of each hidden input, which in your loop will look like:
selectEl.querySelector('input.my_mdc-select__value').value = select.value;

Javascript/jQuery watch for CSS Changes

I have a simple dropdown that opens up a search field when you click it. Even though I have the text field of this search set to autofocus, it's not working for all browsers.
What method of Javascript/jQuery would I use to check if the containing UL css display is set to block, so that I can force the focus to be on the field using .focus().
HTML:
Quick Search
<ul class="dropdown-menu" role="menu">
<li id="li-quicksearch">
<form id="mainSearch" class="form-search">
<p>
<input type="text" id="inputSearch" class="form-control" placeholder="Quick Search" required="" autofocus autocomplete="off">
<button type="submit">SUBMIT</button>
</p>
</form>
</li>
</ul>

EDIT: There is no css change event so you'll have to approach the problem in 1 of 2 ways.
check the dom element in set intervals to see if its css has changed
trigger an event when the css of the dom element is changed by user interaction/your code.
the first way will look something like this:
var element = $(".dropdown-menu");
function checkForChanges()
{
if (element.css('display') == 'block')
{
// do your .focus() stuff here
}
setTimeout(checkForChanges, 500); // does this every half second.
}
or the second way:
$('.toggle').on('click', function() {
$('.dropdown-menu').toggle();
$('.dropdown-menu').trigger('change');
});
$('.dropdown-menu').on('change', function(){
if($(this).css(.css('display') == 'block')
{
// do your .focus() stuff here
}
});

You can check the display value of the ul using pure JavaScript with this:
JS:
var display = document.getElementById('dropdown-menu')[0].style.display;
if (display === 'block') {
//do what you want.
}
Or using jQuery:
if ($('.dropdown-menu').css('display') === 'block') {
//do what you want.
}

It looks like you are using bootstrap to create the dropdown. If that is the case you can use the "shown" event. However you need to attach the event on a container element.
Html
<div class="quickSearchContainer">
Quick Search
<ul class="dropdown-menu" role="menu">
<li id="li-quicksearch">
<form id="mainSearch" class="form-search">
<p>
<input type="text" id="inputSearch" class="form-control" placeholder="Quick Search" required="" autofocus autocomplete="off">
<button type="submit">SUBMIT</button>
</p>
</form>
</li>
</ul>
</div>
Javascript
$('#quickSearchContainer').on('show.bs.dropdown', function () {
$('#inputSearch').focus();
});

I want to thank everyone for their input, but the working solution that I found was to modify the bootstrap JS to allow for an autofocus on toggleClass of the OPEN for the dropdowns. Everyone gets kudos!

jQuery if radio button is selected then proceed to next element

I'm very new to JavaScript and jQuery. I know my code is not the prettiest, but I'm trying to start somewhere.
I have a series of questions that are shown one at a time, and want to create some sort of validation to prevent the user from going to the next question if a radio button on the first button hasn't been selected.
HTML (I have four of these .questionContainers
<div class="questionContainer">
<div class="question">
How much storage do you need?
</div>
<div class="answers">
<ul>
<li>
<label>
<input type="radio" id="storage">1GB or less
</label>
</li>
<li>
<label>
<input type="radio" id="storage">More than 1GB
</label>
</li>
</ul>
</div>
<div class="btnContainer">
<div class="next">
<a class="btnNext">Next</a>
</div>
</div>
</div>
JavaScript
(function(){
var Questions = {
container : $('.questionContainer'),
init : function() {
this.start();
if($('input[type=radio]:checked').length > 0){
this.container.find('a.btnNext').on('click', this.next);
}
},
start : function() {
this.container.not(':first').addClass('hide');
},
next : function() {
var container = $('.questionContainer');
$(this).closest(container).hide(function(){
$(this).closest(container).next().show();
});
}
};
Questions.init();
})();
The specific line that isn't working:
if($('input[type=radio]:checked').length > 0) {
this.container.find('a.btnNext').on('click', this.next);
}
The Problem
When I add the if statement and click a radio button followed by next, it does not go to the next question. I am not receiving any errors in the console.

This binds to the click event only if something is checked at the time that the start function is called (not what you want - it will never be true unless you pre-select a radio button for the user without their action):
if($('input[type=radio]:checked').length > 0){
this.container.find('a.btnNext').on('click', this.next);
}
Try replacing it with this instead:
this.container.find('a.btnNext').on('click', function () {
if($('input[type=radio]:checked').length > 0){
this.next();
}
});
This way you always bind to the click event, but the function that is bound only allows next to be called if something is checked at the time that the function is called (i.e. when the next button is clicked).