Show headers only for collections that are not empty - javascript

I have a couple of lists like this:
<ul>
<li class="list-header">Header</li>
<li>Item 1</li>
<li>Item 2</li>
<li>Item 3</li>
</ul>
By some rules I hide and show <li> items so sometimes the list has visible <li> and sometimes it has no visible <li> elements at all except the one with list-header class, so <li class="list-header"> is still there. I want to hide that header if there are no <li> visible elements in it under header. Though I want the <ul> still to be visible.
How do I do that?

What you could do (demo):
$('ul').each(function() {
$ul = $(this);
$ul.find('.list-header').toggle($ul.has('li:not(.list-header):visible').length != 0);
});
Basically, what the above does is toggling the .list-header (I've wrapped it in the .each() in order to demo different lists) depending on whether the list .has() :visible li elements that are :not(.list-header).
UPDATE
Now it works. Sorry.

You could use the :visible and :not selectors to see if there are any elements present when you change the visibility. This example toggles the visibility when clicking the elements, and hides the header if there are no elements present:
$('li:not(".list-header")').click(function(){
$(this).toggle(10,function(){
var l = $(this).parent().children('li:visible:not(".list-header")').length
if (l>0) $(this).parent().children('li.list-header').show();
else $(this).parent().children('li.list-header').hide();
});
});
working example: http://jsfiddle.net/LDG4J/4/

There is no lh element in HTML. References: HTML5, HTML4.01, HTML 3.2. (You've removed the lh from the question.)
Instead, use an li with a class you style as you see fit (or if you're targeting recent-enough browses, no class required; just style li:nth-child(1) or li:first-child), and just don't hide that li (which will keep the ul visible):
<ul>
<li class='header'>Header</li>
<li>Item 1</li>
<li>Item 2</li>
<li>Item 3</li>
</ul>
Update: I may have misunderstood. If you want to hide the header but keep the ul visible in some way:
A ul with no visible li elements will typically be invisible because it won't have any dimensions. You can override that with CSS, styling the ul to have a specific size (live example):
CSS:
ul.foo {
width: 5em;
height: 5em;
background-color: #eee;
border: 1px solid #aaa;
}
HTML:
<p><code>ul</code> with no visible children:</p>
<ul class='foo'>
<li style="display: none">This is hidden</li>
</ul>
<p><code>ul</code> with a visible child:</p>
<ul class='foo'>
<li>Visible child, note that it wraps</li>
</ul>
And of course you can apply that via jQuery rather than with a static CSS rule:
$("ul.foo").css({
width: "5em",
height: "5em",
backgroundColor: "#eee",
border: "1px solid #aaa"
});
...so you could do that when you're hiding all of the ul's elements, and undo it when showing at least one of them. After making a change:
var ul = $(/*...selector for the relevant list...*/);
if (ul.find('li:visible')[0]) {
// There's at least one visible `li` child
ul.css({/*...styles for when the list is not empty...*/});
}
else {
// There are no visible `li` children
ul.css({/*...styles for when the list is empty...*/});
}
...or better yet, add/remove a class.

try this:
$("ul li:not('.list-header')").each(function(index, val) {
if ($(this).text() == '') {
$(this).hide();
}
});
if (! ($('ul').has("li:visible:not('.list-header')").length)) {
$('li.list-header').hide();
}

Related

jQuery on click, add class but also remove if the class is already present

I have a nav menu that needs to trigger with clicks rather than hovers. When the links are clicked, an .open class would be added to the parent li. If that parent already has the .open class, then it would get removed. It would also be removed if another link is clicked on. So far I can get the class added when clicked and removed when a sibling is clicked, but not removed when it's already .open.
I tried adding a hasClass conditional, but that didn't work either. Seemed like it reruns the function every time it's clicked and therefore ignores the hasClass conditional.
Can anyone provide help? I tried toggleClass, but that didn't work.
$('li a').on('click', function() {
$('li a').parent().removeClass('open');
$(this).parent().addClass('open');
});
ul {
list-style: none;
}
li {
display: inline-block;
padding: 10px;
}
.open {
background-color: yellow;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<nav>
<ul>
<li>
Item 1
</li>
<li>
Item 1
</li>
</ul>
</nav>
To do what you require you can use toggleClass() on the parent li when the element is clicked. To remove the class from all other li elements you can use removeClass() along with not() to exclude the current li. Try this:
$('li a').on('click', function() {
let $li = $(this).parent().toggleClass('open');
$('li').not($li).removeClass('open');
});
ul {
list-style: none;
}
li {
display: inline-block;
padding: 10px;
}
.open {
background-color: yellow;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<nav>
<ul>
<li>
Item 1
</li>
<li>
Item 1
</li>
</ul>
</nav>
You can use
jquery toggleClass() to toggle yellow highlight (.open css class) on click/unclicking the same link.
jquery siblings() to remove .open class on all the other li items.
Below is the link for the demo
https://jsfiddle.net/so1u8hq6/
$('li a').on('click', function() {
$(this).parent().siblings().removeClass('open');
$(this).parent().toggleClass('open');
});
ul {
list-style: none;
}
li {
display: inline-block;
padding: 10px;
}
.open {
background-color: yellow;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<nav>
<ul>
<li>
Item 1
</li>
<li>
Item 2
</li>
<li>
Item 3
</li>
</ul>
</nav>
Late to the party, but, after seeing the provided answers and some of the CSS you use I had to urge with my suggestions:
UX. Avoid styling LI tags in general, or at least set the desired display and move on. Style directly the a tag (with the necessary paddings etc.). You'll not only get less CSS to take care of, but also a larger touch interaction area. Makes no sense to style something yellow if it's not a UI part of something interactable. Also in JS, you don't need to take care about the LI wrappers any more - but only about the actual A Elements.
Don't use common selectors like $('li a') - those might target any LI→A elements in your app. Instead be more specific and use a Class like i.e: .tabs for the parent UL. Both in CSS and JS.
Try to use Event Delegation (in jQuey using the .on() method). Not only it will help you to catch the Event.delegateTarget parent UL where needed, but also the this (the clicked element), but mainly reference all the "group" of a elements enclosed in the common parent. That way you can have as many .tabs in a single page as you like. And yes, thanks to Event delegation you can even add dynamically LI Elements - and your JS will still work as expected.
Since you're using <a href="#"> Anchor elements, instead of (more properly) <button type="button>" Elements, you need to also use Event.preventDefault() in order to prevent the browser its default behavior and that's to follow anchors (scroll the page, navigate, etc...)
Use the selector "a.open" when you want to target and remove the "open" class. By just using "a" (or in other answers on this page - "li") you're uselessly touching elements trying to remove a class that's not there in the first place.
Finally, here's the CSS retouch and the proper jQuery needed for your task:
$(".tabs").on("click", "a", function(ev) {
ev.preventDefault();
$("a.open", ev.delegateTarget).not(this).removeClass("open");
$(this).toggleClass("open");
});
.tabs {
display: flex;
list-style: none;
padding: 0;
}
/* Style your Anchors, not the dummy LI wrappers */
.tabs a { padding: 10px; }
.tabs a.open { background-color: yellow; }
<ul class="tabs">
<li>Item 1</li>
<li>Item 2</li>
<li>Item 3</li>
</ul>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
To explain the only complicated line:
$(
"a.open", // Target just the ones (if any) of class "open"
ev.delegateTarget // inside the common ".tabs" ancestor
)
.not(this) // ... not the clicked element (since later we'll use .toggleClass on it)
.removeClass("open"); // ... remove that class "open"
the rest is pretty self explanatory.
Further read:
jQuery Event Delegation
jQuery event.delegateTarget
Event.preventDefault
So you only want the yellow background to appear as a signifier of user interaction rather than for the background color to be displayed? Have you tried using the mousedown/mouseup functions instead of .on('click', function(){...}?
I was able to simulate the click event where the color showcases via this method:
$('li a').mousedown(function() {
$('li a').parent().removeClass('open');
$(this).parent().addClass('open');
});
$('li a').mouseup(function() {
$('li a').parent().removeClass('open');
});
ul {
list-style: none;
}
li {
display: inline-block;
padding: 10px;
}
.open {
background-color: yellow;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<nav>
<ul>
<li>
Item 1
</li>
<li>
Item 1
</li>
</ul>
</nav>

How can i detect class name of an element using template literals inside querySelector

I have two navigation boxes where first one has a CSS Class .one and Second one is blank. For first navigation box, I given a border with JavaScript by detecting the class name .one. But I getting border for second navigation box too eventhough it don't have a class. Here i use template literals approach. I know that i can fix this using class name directly inside the querySelectorAll method as follows let li = document.querySelectorAll(".one > ul li");. But I need template literals solution which is most usefull for me to use some other projects too. Mainly i need to represent class name as a variable. Following is my code. Can anyone help me on this. Thanks in Advance!
let parents = document.querySelector(".one");
let li = document.querySelectorAll(`${parents.tagName} > ul li`);
li.forEach((elem)=>{elem.style.border="1px solid red"});
nav {font-family:arial;width:15rem;}
nav ul {list-style:none;padding:0;margin:1rem;padding-left:.5rem;}
nav ul a {color:#777;text-decoration:none;padding:.5rem;}
<nav class="one">
<ul>
<li>Home</li>
<li>About
<ul>
<li>Vision</li>
<li>Mission</li>
</ul>
</li>
<li>Contact</li>
</ul>
</nav>
<br>
<nav>
<ul>
<li>Home</li>
<li>About</li>
<li>Contact</li>
</ul>
</nav>
Try replacing this line:
let li = document.querySelectorAll(`${parents.tagName} > ul li`);
with this one:
let li = parents.querySelectorAll(`ul li`);
The reason it doesn't work for you as you expected, is because you are matching all the elements with the query selector nav > ul li within the document, and you are completely ignoring the class name of the nav tag you have selected in parents variable.
Otherwise, you can simply do this instead:
let li = document.querySelectorAll(`.one > ul li`);
li.forEach((elem)=>{elem.style.border="1px solid red"});
or just use the CSS:
.one > ul li {
border: 1px solid red;
}
or if you want to select the first element (I don't know what are your intentions, but I'm guessing according to your code):
.one:first-child > ul li {
border: 1px solid red;
}
Don't need JavaScript. It can be possible by only CSS.
.one > ul > li { border: 1px solid red}
or in your JS change
let li = document.querySelectorAll(`${parents.tagName} > ul > li`);

Show next sibling element if is previous element hovered with pure JavaScript

I have this snippet of html
ul { display:none }
test 1
test 2
test 3
<ul class="hh-ul-1 mm-listitem">
sub 1
</ul>
Test 4
<ul class="hh-ul-1 mm-listitem">
sub 2
</ul>
By default ul elements are hidden.
I'm trying to achieve when the a element is hovered to show only ul element which is the next sibling.
For example, if test 3 link has hovered, the ul element with sub 1 link needs to show up and to stay while the a and ul are hovered.
I'm not so experienced, so any help would be appreciated.
Have a look at adjacent sibling combinator
I add focus so you can keep the UL open
Also the a in the UL should be in an li. That makes it somewhat harder to make a sub-sub menu
ul { display:none; position: absolute; top:50px }
a:hover + ul { display: block }
a:focus + ul { display: block }
test 1
test 2
test 3
<ul class="hh-ul-1 mm-listitem">
<li>sub 1</li>
</ul>
Test 4
<ul class="hh-ul-1 mm-listitem">
<li>sub 2</li>
</ul>

Multiple dropdown navigation - how to change the trigger button

I am struggling with one of my dropdowns.
Currently it is set up to be triggered by an i tag to drop down the sub menu.
$('nav li i').click(function() {
I want to change it to (nav li a) so it is not the icon that has to be pressed
I also have the code:
var child = $(this).index('nav ul li i');
but i am not sure what to change this to?
You can see all the code in jsfiddle.
http://jsfiddle.net/susannalarsen/VNYAx/
Since I do not see the <a> element anywhere, I have changed the <i> to <a> for demonstration purposes. You can see the example on http://jsfiddle.net/VNYAx/3/
Basically I changed
$('nav li i').click(function() {
to
$('nav li a').click(function() {
And also
var child = $(this).index('nav ul li i');
to
var child = $(this).index('nav ul li a');
Is this what you need?
Instead of using the index of the icon as a way to identify which dropdown you want to slide down, you can save a reference to that dropdown by searching for '.dropdown' within the element clicked.
$('nav li').click(function () {
var $childDropdown = $(this).find('.dropdown');
if ($childDropdown.is(':visible')) {
$('.dropdown').slideUp(300);
} else {
$('.dropdown').slideUp(300);
$childDropdown.slideDown(300);
}
});
http://jsfiddle.net/9Fk7j/2/
Just an alternative approach to this problem using .slideToggle(). If you need anything explaining please comment and I will edit the answer. I have commented the JavaScript below. I also removed the extra <div> in the markup as the nested <ul> is a perfectly good container.
Demo
HTML
<nav id="moo">
<ul>
<li>Item A
<ul>
<li>Item 2</li>
<li>Item 3</li>
<li>Item 4</li>
</ul>
</li>
<li>Item B
<ul>
<li>Item 7</li>
<li>Item 8</li>
<li>Item 9</li>
</ul>
</li>
</ul>
</nav>
CSS
ul {
padding: 0;
margin: 0;
}
li {
display: inline;
}
nav li {
position: relative;
}
ul ul {
display: none;
position: absolute;
border:1px solid #ccc;
padding: 10px;
}
ul ul li {
display: block;
}
JavaScript
var $allSubMenus = $('ul ul'); // handle to all submenus
$('nav li a').click(function (e) {
var $li = $(this).closest('li'); // get parent <li> of the <a> clicked on
var $subMenu = $li.find('ul'); // get our submenu
$allSubMenus.not($subMenu).slideUp(300); // hide all other submenus
$subMenu.slideToggle(300); // show our submenu
e.stopPropagation(); // stop event bubbling further
});
$(document).click(function () {
$allSubMenus.hide(); // no need to reselect, just use handle
});

How to cancel a CSS style set by 'hover child' selector on event?

I am making a CSS based menu, with submenu items that pop up when the root element is hovered. the problem I have is that I want the CSS menu to close when I click an item in the list, but at that point I am still technically hovering over the top element, so I figured I had to use javascript to hide the menu. But when I set the display property, I set it forever and it overrides the hover selector of the parent node. And so the submenu doesn't show up anymore.
This must be pretty common, but I can't find any answers...
Any help much appreciated!
html:
<ul class="level1">
<li>one
<ul class="level2">
<li id="test">two</li>
<li>three</li>
</ul>
</li>
</ul>
css:
.level1 li:hover > ul {
display: inline;
}
.level2 {
display: none;
}
js:
document
.getElementById('test')
.addEventListener('click',function () {
this.parentNode.style.display = 'none';
// After this the menu doesn't open anymore
// because the style is overriden
});
Here's the jsfiddle
You can try this.
<ul class="level1">
<li class="hoverMe">one
<ul class="level2">
<li id="test">two</li>
<li>three</li>
</ul>
</li>
</ul>
.hoverMe:hover > ul {
display: inline;
}
var test = document.getElementById('test');
test.onclick = function () {
this.parentNode.parentNode.className = "";
};
var level1 = document.getElementsByClassName('level1')[0];
level1.getElementsByTagName("li")[0].onmouseover = function () {
if (this.className != "hoverMe") {
this.className = "hoverMe";
}
};

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