Why is the jQuery function showHide() undefined? - javascript

I'm really new at trying to use jQuery, so please forgive me for asking what is likely a simple question. Perhaps it isn't even related to jQuery, but anyway, here's the scenario. I'm trying to put in a hidden div which I only want to show up when the user hovers their mouse over the Learner's anchor tag on the page. I've started with only one anchor tag, to get it working first before implementing the rest of them. I've downloaded a jQuery library and included a reference to it, so here's some of what I've got in my page's head section:
<script src="js/jquery-1.11.1.js" type="text/javascript" ></script>
<style type="text/css">
#navcontainer ul { list-style-type: none; }
#navcontainer ul li { display: inline; }
#navcontainer ul li a
{
text-decoration:none;
padding: .2em 1em;
}
</style>
Next I've defined an unordered list, using the styling above to make it horizontal, and I've got a hidden div after it, which I want to show when the user moves their mouse over the first anchor in the unordered list. Here's the relevant HTML from within the body tag:
<body>
<div id="navcontainer">
<ul>
<li>Home</li>
<li>Learners</li>
<li>Teachers</li>
<li>Businesses</li>
<li>Contact Us</li>
</ul>
<div id="dropdown1" style="visibility:hidden;">
<ul>
<li>Description A</li>
<li>Description B</li>
<li>Description C</li>
</ul>
</div>
<!-- other HTML code -->
</body>
However, when I run this from within the browser (IE11) nothing happens. Using the F12 web developers tools built into IE11 I learn that it giving an error of "showHide is undefined". Why is it doing that? The showHide() function is most certainly in the jquery-1-11.1.js file, which most certainly is in my js folder. What have I done wrong, or failed to take into account?

jQuery works kinda different than that. You have to make it look like this:
$("#dropdown1").toggle()
You better make a javascript file and separate the JS from the HTML:
HTML:
<body>
<div id="navcontainer">
<ul>
<li>Home</li>
<li>Learners</li>
<li>Teachers</li>
<li>Businesses</li>
<li>Contact Us</li>
</ul>
<div id="dropdown1" style="visibility:hidden;">
<ul>
<li>Description A</li>
<li>Description B</li>
<li>Description C</li>
</ul>
</div>
<!-- other HTML code -->
</body>
The JS
$(function(){
$("#navcontainer li a").click(function(){
if( this.href.indexOf("#") != -1 ) {
$( $(this).attr("href") ).toggle(); // $( "#container1" )
}
});
});
What this does is on the navcontainer li click, we make a handler, which does something if it contains a #. Then we select that element #container1 which is in the href, also is the selector for the element which we want to show. And we toggle that element.

There is no such function as showHide you could use toggle() or show() or hide()
in you current scenario uou would couple them with $(this). or your chosen selector.
As an example of targetting a particular element with jQuery we have added the class hover-learners and target it with the selector below.
HTML:
<div id="navcontainer">
<ul>
<li>Home
</li>
<li>Learners
</li>
<li>Teachers
</li>
<li>Businesses
</li>
<li>Contact Us
</li>
</ul>
<div id="dropdown1">
<ul>
<li>Description A
</li>
<li>Description B
</li>
<li>Description C
</li>
</ul>
</div>
Add the below javascript as a file or within <script type="text/javascript"> code here</script> after including your jQuery library file.
Javascript:
// wrap everything in jQuery's ready function to make sure the page has fully loaded before executing the javascript
$(document).ready(function () {
//select learners and apply mouseover event
$('.hover-learners').on('mouseover', function () {
$('#dropdown1').show();
});
//select learners and apply mouseout event
$('.hover-learners').on('mouseout', function () {
$('#dropdown1').hide();
});
});
Also since the show and hide methods manipulate the display CSS property I have added
CSS:
#dropdown1 {
display:none;
}
and remove the inline style="visibility:hidden" from the #dropdown1
Working demo here: http://jsfiddle.net/robschmuecker/J6U7d/

Related

How toggle nav bar visibility?

I'm a beginner in javascript. I want to add hide and show button using toggle methods. Here is my html.
<body>
<header>
<li>Mécanique
<ul class="sub-menu">
<li>Mécanique du point</li>
<li>Mécanique du solide</li>
</ul>
</li>
</header>
</body>
Learn how things work before you ask a question here at StackOverflow. We all still learning, but, we have to try things ourselves.
Besides that, here's how to use jQuery to hide/show .sub-menu by clicking the a tag that contains 'Mécanique' word, and I'll give it an ID so we can reference it later by JavaScript.
// we put everything in the document.ready handler to ensure that the document has finished loading.
$(document).ready(function() {
// reference the 'a' tag that I gave it an id of 'trigger', and also referencing the .sub-menu ul.
var trigger = $('#trigger'),
menu = $('.sub-menu');
// adding the event listener to the #trigger to hide/show the .sub-menu ul.
trigger.on('click', function(e) {
// cancel the default behaviour when clicking a link.
e.preventDefault();
// hide/show the menu.
menu.toggle();
});
});
ul.sub-menu {
// by default, let's make the .sub-menu ul hidden.
display: none;
}
<body>
<header>
<li>Mécanique
<ul class="sub-menu">
<li>Mécanique du point</li>
<li>Mécanique du solide</li>
</ul>
</li>
</header>
<script
src="https://code.jquery.com/jquery-3.3.1.min.js"
integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
crossorigin="anonymous"></script>
</body>
Hope I pushed you further.

jQuery - known class of child: find next descendent of parent in top (from parent ID)

I've been searching a lot for this, without any solution so far. As you might also have seen the topic title might be a little hard to interpret and that's because I'm not quite sure how to explain it shortly.
The problem
Looking at the HTML below, I know the class of the last element called "active" and this element is chosen dynamically in jQuery, based on which site the visitor is on currently - i.e. different elements has this class depending on the site. On another site the li with class first-sub-li could have the class active (or for that matter the li with class first). This class is, as said, added dynamically based on the site with jquery. From here on I wish to identify the parent of the element with active which is a direct descendent of top-parent and add a class called active-parent to this. I.e. in the case below i wish to add the active-parent class to the li with class second.
EDIT: Please note that the "depth" of the list can vary, therefore also requiring a "dynamic" approach to picking out the parent. I completely forgot this in the initial writing.
<ul id="top-parent">
<li class="first">
<ul class="first-sub-ul">
<li class="first-sub-li"></li>
</ul>
</li>
<li class="second">
<ul class="second-sub-ul">
<li class="second-sub-li">
<ul class="second-sub-sub-ul">
<li class="second-sub-sub-li active"></li> <!-- Here -->
</ul>
</li>
</ul>
</li>
</ul>
So far I've tried the following jQuery without succes as it doesn't identify it.
EDIT 2: This actually does work, but initially it didn't as it apparently was called before the class was loaded, despite appearing later in the javascript document. Wrapping it in a $(window).on("load", function() solves the problem as shown below.
$(window).on("load", function() {
$(".active").closest("#top-parent > li").addClass("active-parent");
});
The original code was just $(".active").closest("#top-parent > li").addClass("active-parent");
You can start traversing up with .parent(), it will excluding the self li.
$(".active").parent().closest("li").addClass("active-parent");
You can use :has() selector
$('#top-parent > li:has(.active)').addClass("active-parent");
$('#top-parent > li:has(.active)').addClass("active-parent");
.active-parent {
background-color: red
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul id="top-parent">
<li class="first">
<ul class="first-sub-ul">
<li class="first-sub-li"></li>
</ul>
</li>
<li class="second">
<ul class="second-sub-ul">
<li class="second-sub-li">
<ul class="second-sub-sub-ul">
<li class="second-sub-sub-li active"></li>
<!-- Here -->
</ul>
</li>
</ul>
</li>
</ul>
I think this is what you're looking for. Find all li which are direct descendants of topmost-parent and filter that for the one which has a child .active. Apply the class.
$('#top-parent > li').filter(function(e){
return $(this).find('.active').length>0;
}).addClass("active-parent");
.active-parent{background-color:red}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul id="top-parent">
<li class="first">
<ul class="first-sub-ul">
<li class="first-sub-li">1.1</li>
</ul>
</li>
<li class="second">
<ul class="second-sub-ul">
<li class="second-sub-li active">2.1</li> <!-- Here -->
</ul>
</li>
</ul>

How can I change the style properties of this element?

I'm trying to make a drop down menu for the mobile version of a website and can't seem to figure out what I'm doing wrong. I have the initial position where I want it (fixed in the upper right corner of the screen) but it does nothing when you click on the Menu tab.
Here's my JSFiddle
<div id="mobile-nav-wrapper">
<ul id="mobile-nav">
<li>Main Menu</li>
<ul>
<li>Home</li>
<li>About</li>
<li>Contact</li>
<li>Register</li>
<li>FAQs</li>
<li>Facebook</li>
</ul>
<li>This Page</li>
<ul>
<li>Some Text</li>
<li>Who?</li>
</ul>
</ul>
<span id="mobile-nav-button" onclick="pullmenu('#mobile-nav-wrapper')">Menu</span
</div>
Your JavaScript function isn't a global. You have configured JSFiddle to wrap it in an onload handler. It isn't accessible outside the scope of that function.
Don't use intrinsic event attributes, they depend on globals. Bind your event handlers with JS instead.
span isn't an interactive element. It doesn't appear in the focus order so has serious accessibility implications when you depend on people interacting with it. Use a button instead. Apply CSS if you don't like the way it looks.
<button type="button" id="mobile-nav-button">Menu</button>
<script>
document.getElementById('mobile-nav-button').addEventListener('click', function (evt) {
pullmenu('#mobile-nav-wrapper');
});
function pullmenu(etc) { etc }
</script>
JavaScript
<script>
function pullmenu(menu) {
var x = document.getElementById(menu).style;
if (x.top == "-15em") {x.top="0";}
else {x.top="-15em";}
}
</script>
HTML :
<span id="mobile-nav-button" onclick="pullmenu('mobile-nav-wrapper')">Menu</span>
Example

jQuery hide an element if another element contains text

I have a div that I wish to hide using jQuery, only if I'm in a certain category, so I want to base the hiding of the div based on my breadcrumbs. I think I have the jQuery right, but it isn't hiding the div?
<div class="breadcrumbs">
<ul class="nav">
<li>Home</li>
<li>Tshirts</li>
<li>Mens</li>
</ul>
</div>
<div class="hide-me">I want to hide</div>
<script type="text/javascript">
jQuery(window).ready(function(){
if(jQuery('.breadcrumbs ul.nav li:nth-child(2)').text() == "Tshirts"){
jQuery('.hide-me').hide();
}
});
</script>
jQuery('.breadcrumbs ul.nav li:nth-child(2)').text()
Is strange, why are you hardcoding this so much? You're specifically asking for that list, and only if it is within a very specific tree.
It would be easier if you just changed your HTML
<div class="breadcrumbs">
<ul class="nav">
<li>Home</li>
<li id="secondlist">Tshirts</li>
<li>Mens</li>
</ul>
</div>
and then
$("#secondlist").text() == "Tshirts";
Check if
$('.breadcrumbs ul.nav li:nth-child(2)').text()
is really getting the value, I think that is the principal problem.

Creating navigational pages with jquery

I actually didn't really know how to phrase the question title, but here is the description. Suppose I'm using jQuery to show/hide uls that are stacked on top of each other (absolutely positioned). For example:
<ul id="one">
<li>blah</li>
<li>blah2</li>
</ul>
<ul id="two">
<li>blah</li>
<li>blah2</li>
</ul>
I have a controller button, that when pressed, simply changes the z-index of these uls. The controller button is literally just:
My button
With jQuery code that does: (I'm using the jQuery cycle plugin)
$('#mybutton').click(function() {
// check which ul is currently shown
// change z-index, so that the next ul is to be shown
});
THE QUESTION:
In my site, I have several pages that I would like to point to the second ul, so that when clicked, it'll bring them to the page with all of the uls, but only the second one will be shown. It would be the same if the person went to the page, had the default first ul shown, and then clicked "next" to proceed to the next ul. I am simply wondering if it's possible to avoid pressing "next", and just bring the user directly to the page and have the second ul shown.
I think you can use the hash-tag from the URL. You can then write an if statement like this:
if(location.hash === "#2"){
$("#one").hide();
}else{
$("#two").hide();
}
Or directly as a copy and paste example:
<html>
<script src="http:////ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js"></script>
<script>
$(function(){
if(location.hash === "#2"){
$("#one").hide();
}else{
$("#two").hide();
}
$('#mybutton').click(function(e) {
$("ul").toggle(); //quick n dirty! only works with 2 lists :)
e.preventDefault();
});
});
</script>
<body>
My button
<ul id="one">
<li>First Item!</li>
<li>blah</li>
<li>blah2</li>
</ul>
<ul id="two">
<li>Second Item!</li>
<li>blah</li>
<li>blah2</li>
</ul>
To second page (you might have to refresh, notice the #2 at the end of the url!)
​</body>
</html>
Also notice I've inserted a e.preventDefault(); at #mybutton's click listener to prevent the URL changing back on clicking.
If I am understanding you correctly, perhaps you can accomplish this via a page wrap with a unique id per page? You can swap the id out with JS or server side logic, depending on what you're trying to do.
<div id="page-one">
<ul id="one">
<li>blah</li>
<li>blah2</li>
</ul>
<ul id="two">
<li>blah</li>
<li>blah2</li>
</ul>
</div>
then your css will be #page-one #one { display:block }; #page-two #one { display : none }; etc.

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