Develop Reference

How to show element only if other element contains something using jQuery?

My guess is what I want to achieve should be easy, but due to my lack of knowledge of front-end development, I cannot manage to solve issue. Have a page that works with AJAX-filters that users can select. Filters that are currently applied show up within <div> with id=current-filters.
HTML looks like this:
<div id="current-filters-box">
<div style="margin-bottom: 15px">
<strong>Current filters:</strong>
<div id="current-filters">
<!-- here every single applied filter is displayed -->
</div>
</div>
</div>
Need to hide the the entire DIV current-filters-box in case no filter is applied.
The page uses a Javascript file, bundle.js which is massive, but contains the following line:
s=document.getElementById("current-filters")
Therefore tried the following if-statement to hide the DIV:
if(s.length<1)$('#current-filters-box').hide()
and
if(s=0)$('#current-filters-box').hide()
But this does not seem to have any effect. Can someone tell, what I did wrong?
Demo of page can be found here
EDIT: this is what the HTML looks like when filters are applied:
<div id="current-filters-box">
<div style="margin-bottom: 15px">
<strong>Current filters:</strong>
<div id="current-filters">
<div class="badge-search-public">
<strong>Humanities & Languages</strong> <span class="x" data-property="disciplines" data-value="4" onclick="filter.removeFilter(this)">×</span>
</div>
<div class="badge-search-public">
<strong>January</strong> <span class="x" data-property="months" data-value="1" onclick="filter.removeFilter(this)">×</span>
</div>
</div>
</div>

Both of your conditions are incorrect or I would say they are not doing what you think they do.
s.length will always prints undefined so instead of s.length<1 you could use s.children.length
and the second one is not a condition rather it is an assignment
s==0 // condition
s=0 //assignment
the correct condition for your requirement would be
if(s.children.length<1){
I have assigned snippets for illustration.
Without filters
s = document.getElementById("current-filters")
console.log(s.children.length);
if (s.children.length < 1) {
$('#current-filters-box').hide(1000)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="current-filters-box">
filter box
<div style="margin-bottom: 15px">
<strong>Current filters:</strong>
<div id="current-filters">
<!-- here every single applied filter is displayed -->
</div>
</div>
</div>
Without filters
s = document.getElementById("current-filters")
console.log(s.children.length);
if (s.children.length < 1) {
$('#current-filters-box').hide(1000)
}
<div id="current-filters-box">
<div style="margin-bottom: 15px">
<strong>Current filters:</strong>
<div id="current-filters">
<div class="badge-search-public">
<strong>Humanities & Languages</strong> <span class="x" data-property="disciplines" data-value="4" onclick="filter.removeFilter(this)">×</span>
</div>
<div class="badge-search-public">
<strong>January</strong> <span class="x" data-property="months" data-value="1" onclick="filter.removeFilter(this)">×</span>
</div>
</div>
</div>

Try this .
if( $('#current-filters').is(':empty') ) {
$('#current-filters-box').hide()// or $('#current-filters-box').css("display","none")
}

You are performing an assignment, try..
if (s.children.length)

Using vanilla JavaScript, you can check if the current-filters div is empty or not and toggle the parent div current-filters-box like this:
s= document.getElementById("current-filters");
t= document.getElementById("current-filters-box");
if(s.children.length<1) {
t.style.display = 'none';
// t.style.visibility= 'hidden'; <<-- use this if you want the div to be hidden but maintain space
}
else {
t.style.display = 'block';
// t.style.visibility= 'visible'; <<-- use this if you used visibility in the if statement above
}

You can achieve this by adding your own variable which counts or maintains your applied filters, e.g.
var applied_filter_count = 0;
at every time filter is applied
applied_filter_count++;
if(applied_filter_count) {
$('#current-filters-box').show()
}
and at every time filter is removed
applied_filter_count--;
if(!applied_filter_count) {
$('#current-filters-box').hide()
}
and by default current-filters-box should be display:none

Removing div's and keep content

I'm trying to remove the following DIV's:
<div class="whatever_name">
<div class="whatever_name">
<h2>subtitle</h2>
<p>content<p>
</div>
</div>
and need the following output:
<h2>subtitle</h2>
<p>content<p>
Using jQuery, I can not use remove() because it clear the content too. With pure javascript, happens the same.
I have no idea how to accomplish this issue.
Any idea?
EDIT:
Not always the structure is the same. It can vary, i.e.:
<div class="whatever_name">
<div class="whatever_name">
<div class="whatever_name">
<h2>subtitle</h2>
<p>content<p>
</div>
</div>
</div>
Just need an iterator that can handle such task.

Use unwrap() method twice on the children element.
$('.content .post-12')
// get children elements, or use contents()
.children()
// use unwrap twice to unwrap two parents
.unwrap().unwrap()
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="content">
<div class="post-12">
<h2>subtitle</h2>
<p>content</p>
</div>
</div>
UPDATE : With the updated content you just need to change the selector with your requirement.
$('div > div > h2,div > div > p').unwrap().unwrap()
// or use
// $('div > div:has(h2):has(p) > *')
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="whatever_name">
<div class="whatever_name">
<div class="whatever_name">
<h2>subtitle</h2>
<p>content
<p>
</div>
</div>
</div>

Change list-group-item from hidden to visible with JS

I have a list which contains of several items that are hidden.
In my JS i want a function that changes the items of this list so it becomes visible. I want each item to become visible if a certain event has happened. The event is working fine and can be considered as shakeCount= 6, to test it properly.
Here is my list:
<div class="container">
<div class="list-group">
<div id="s1">Shake1</div>
<div id="s2">Shake2</div>
<div id="s3">Shake3</div>
</div>
</div>
What i tried so far and didn't work:
function nR(){
if (shakeCount>5)
document.getElementbyId("s1").style.visibility ="visible";
}
Thanks in advance!

Have you tried using Toggle? I would recommend it but you may need to remove the "hidden" class from your elements and add in the style="display: none;" attribute to each in order to default them to hidden.
<div class="container">
<div class="list-group">
<div id="s1">Shake1</div>
<div id="s2">Shake2</div>
<div id="s3">Shake3</div>
</div>
</div>
function nR(){
if (shakeCount>5)
document.getElementbyId("s1").toggle();
}

First, you're using getElementbyId -- it should be getElementById (missing capital 'B').
Second, you've made the #shake links visibility:hidden, but you are targeting the wrapping div when you run your js.
var shakeCount = 6;
if (shakeCount>5)
document.getElementById("s1").style.visibility ="visible";
.hidden {visibility: hidden;}
<div class="container">
<div class="list-group">
<div id="s1" class="list-group-item hidden"><a href="#shake1" >Shake1</a></div>
<div id="s2" class="list-group-item hidden"><a href="#shake2" >Shake2</a></div>
<div id="s3" class="list-group-item hidden"><a href="#shake3" >Shake3</a></div>
</div>
</div>
The above code hides the wrapping div elements instead of the links so that they are shown when the js runs.

Toggle individual divs in a loop

In rendering out data within HTML, which prints out a div down the page, for every row found in the database, I'm trying to find a way to allow each button that sits in each div to toggle the individual example when clicked (with a default of display:none upon loading the page) - something such as:
function toggle_div(id) {
var divelement = document.getElementById(id);
if(divelement.style.display == 'none')
divelement.style.display = 'block';
else
divelement.style.display = 'none';
}
An example of the final markup :
<div>
<div class="wordtitle">Word</div>
<div class="numbers">1</div>
<div class="definition">Definition</div>
<button class="button" id="show_example" onClick="toggle_div('example')">Show example</button>
<div class="example" id="example">Example 1</div>
</div>
<div>
<div class="wordtitle">Word</div>
<div class="numbers">2</div>
<div class="definition">Definition</div>
<button class="button" id="show_example" onClick="toggle_div('example')">Show example</button>
<div class="example" id="example">Example 2</div>
</div>
getElementById() only toggles the first div's example, and getElementsByClass() hasn't seemed to work so far - not too sure how to do this - any ideas much appreciated!

First rule, do not insert multiple elements with the same ID. IDs are meant to be unique.
What you need is to toggle the example near the button you clicked, and not any (or all) .example to be showed / hidden. To achieve this, considering you used the [jquery] tag in your question, you can either use a selector to get the nearest .example of your button, or use jQuery's built-in functions to get it (.siblings()).
I would personally put the onclick out of your markup, and bind this custom function in your javascript.
Another important thing : if javascript is disabled client-side, the user won't ever see your example, as they are hidden by default in CSS. One fix would be to hide it initially with JS (see the snippet for this).
Here's a demonstration of what I mean :
$('.example-trigger').click(function() {
//Use the current button which triggered the event
$(this)
//Find the sibling you want to toggle, of a specified class
.siblings('.example-label')
//Toggle (hide or show) accordingly to the previous display status of the element
.toggle();
});
//Encouraged : hide examples only if Javascript is enabled
//$('.example-label').hide();
.example-label {
display: none;
/* Discouraged : if javascript is disabled, user won't see a thing */
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<div>
<button class="example-trigger">Toggle example 1</button>
<span class="example-label">Example 1</span>
</div>
<div>
<button class="example-trigger">Toggle example 2</button>
<span class="example-label">Example 2</span>
</div>
<div>
<button class="example-trigger">Toggle example 3</button>
<span class="example-label">Example 3</span>
</div>

As #Sean stated, you need the ID to be unique since that's the way you are getting your elements.
$words .= '<div class="wordtitle">' . $word .'</div>
<div class="numbers">' . $i . '</div>
<div class="definition">' . $definition . '</div>
<button class="button" id="show_example" onClick="toggle_div(\'example\''.$i.')">
show example</button>
<div class="example" id="example'.$i.'">' . $example . '</div>
<br/><br/>';
$i++;
#show_example will also be repeating so you will probably want to change that to a class.

Another answer, only because I had the answer ready and was called away before I could post it. So here it is.
Notice that for repeating elements, classes are used instead of IDs. They work just as well, and (as everyone else has already said), IDs must be unique.
jsFiddle demo
HTML:
<div class="def">
<div class="wordtitle">Aardvark</div>
<div class="numbers">1</div>
<div class="definition">Anteater</div>
<button class="button show_example">show example</button>
<div class="example" id="example">The aardvark pushed its lenghty snout into the anthill and used its long, sticky tongue to extract a few ants.</div>
</div>
<div class="def">
<div class="wordtitle">Anecdote</div>
<div class="numbers">2</div>
<div class="definition">Amusing Story</div>
<button class="button show_example">show example</button>
<div class="example" id="example">The man told an anecdote that left everyone laughing.</div>
</div>
jQuery:
var $this;
$('.show_example').click(function() {
$this = $(this);
if ( $this.hasClass('revealed') ){
$('.example').slideUp();
$('.show_example').removeClass('revealed');
}else{
$('.example').slideUp();
$('.show_example').removeClass('revealed');
$this.parent().find('.example').slideDown();
$this.addClass('revealed');
}
});

Hide parent div if child div is missing

Is it possible at all to hide a parent div if there is a child div missing?
In the example below I would like to hide the parent div of "#live-sessions" if some of the divs are missing such as .views-content and .views-row.
This is what it looks like when the divs are there:
<div id="live-sessions">
<div class="container">
<div class="row">
<div class="col-sm-3">
<h3 class="session-title">Sessions Live Now</h3>
<div class="col-sm-9">
<div class-"view-display-id-live_sessions">
<div class="views-content">
<div class="views-row">
</div>
<div class="views-row">
</div>
</div>
</div>
</div>
</div>
</div>
</div>
This is what it looks like when the divs are missing:
<div id="live-sessions">
<div class="container">
<div class="row">
<div class="col-sm-3">
<h3 class="session-title">Sessions Live Now</h3>
<div class="col-sm-9">
<div class-"view-display-id-live_sessions">
</div>
</div>
</div>
</div>
</div>
I tried using the :empty selector with the parent method, but my child div contains some blank lines so it doesn't think it's empty. Also I would like to hide the parent of the parent of the empty div.
$(".view-display-id-live_sessions:empty").parent().hide();

You have a typo in your html:
class-"view-display-id-live_sessions"
should be
class="view-display-id-live_sessions"
you can try the following jQuery code:
if ($(".view-display-id-live_sessions").html().trim() == '') {
$(".view-display-id-live_sessions").parent().parent().hide();
}
jqVersion demo

Use jQuery has() in a negative if test - http://api.jquery.com/has/
if(!$('#parent').has('.child')){
$('#parent').hide();
}

There isn't a one-line-query for this. Following code would do the trick:
$('#live-sessions .row').each(function(idx, row) {
if ($(row).find('.views-content').length == 0) {
$(row).hide();
}
});

If you want to keep using jQuery, you could instead do:
if ( ! $(".view-display-id-live_sessions").children().length ) { /* your logic */ }
Note that there's a syntax error in your code:
<div class-"view-display-id-live_sessions">
Should be
<div class="view-display-id-live_sessions">

If you understand your question:
First you need to check the number of .views-row divs. If the length is zero hide the parent div.
Ex:
if ($('.views-row').length < 1)
$('#live-sessions').hide();
Good Luck.

You need to trim the blank spaces, correct a typo and test for the text within the div -
class="view-display-id-live_sessions" // note the equals sign after class
The code to do the hiding (EDIT re-read problem again):
var liveSessionsText = $.trim( $('.view-display-id-live_sessions').text() );
if(0 == liveSessionsText.length) {
$('.view-display-id-live_sessions').closest('.row').hide();
}
The div with class="row" is the parent of the parent of view-display-id-live_sessions.