Develop Reference

Fading in text via text button

I am currently working in WordPress and I want to fade in a bit of text by clicking on another text line.
I just want purely text (For example text as a button) and have a nice fade-in effect.
I have already tried this but it does not work in wordpress.
I got this from somewhere online:
http://jsfiddle.net/zcWJ6/11/
html:
<span class="button">Text button</span>
<span class="fadein">You just clicked on "Text button"</span>
css:
.button { cursor: pointer; }
Jquery:
$('.fadein').hide();
$('.button').on('click', function(){
$('.fadein').fadeIn(2000);
});

#Satpal is right on this one, you need to use jQuery rather than $ when working in wordpress. The new code would look like this:
jQuery('.fadein').hide();
jQuery('.button').on('click', function(){
jQuery('.fadein').fadeIn(2000);
});
the code above should work just fine in wordpress for what you want to do, assuming you have the jQuery library already called and you're putting the code in the right place. As #Giancarlo mentioned you should also wrap it in a document ready script, but it also needs to be in jQuery form like so:
jQuery(document).ready(function(){
jQuery('.fadein').hide();
jQuery('.button').on('click', function(){
jQuery('.fadein').fadeIn(2000);
});
});
put this code into a separate .js file and call it in your theme's functions.php file using wp_enqueue_script
it should work just fine

Try executing your jQuery code after the jQuery JavaScript library has loaded. Additionally, wrap your jQuery code around an on document ready scope.
// Shorthand for $(document).ready()
$(function(){
// Your jQuery code goes here
});

jQuery shows hidden content on refresh

I use this fancy little jQuery toggle on my site, works great. But now I have a little larger text area I want to hide, and therefore I've included it in another php file, but when the site opens\refreshes the content is briefly shown and then hidden? Have I done something wrong or does it simply not work right with includes in it ?
Show me?
<div class="content">
<?php include 'includes/test.php'?>
</div>
<script>
jQuery(document).ready(function() {
var par = jQuery('.content');
jQuery(par).hide();
});
jQuery('#toggleMe').click(function() {
jQuery('.content').slideToggle('fast');
return false;
});
</script>

Use css to hide it
.content{
display:none;
}
Also
var par = jQuery('.content');
is a jQuery object so don't need to wrap it again as
jQuery(par).hide();
Just use par.hide(); but in this case, when you will use css to hide the element, then you don't need this anymore.

That will happen. The document briefly shows all the HTML before executing the code in your ready handler. (It has nothing to do with the PHP include.) If you want an element hidden when the page loads, hide it using CSS.
#myElement {
display: none;
}
The toggle should still work correctly.

You just need to don't use jquery document ready function. just use style attribute.
Show me?
<div class="content" style="display:none">
<?php include 'includes/test.php'?>
</div>
<script>
jQuery(document).ready(function() {
jQuery('#toggleMe').click(function() {
jQuery('.content').slideToggle('fast');
return false;
});
</script>

If this information is sensitive/not supposed to be seen without access granted, hiding it with CSS will not fix your problem. If it's not, you can ignore all of this and just use CSS with a display: none property.
If the information IS supposed to be hidden:
You need to only load the file itself on-demand. You would request the data with AJAX, do a $('.content').html() or .append() and send the result back directly from the server to the browser using something like JSON.

You are using the "ready" function that meant it will hide the element when the document is ready (fully loaded).
You can hide it using css:
.contnet { display: none; }

how you render you site server side does not affect how the site is loaded on the browser, what affects it is how the specific browser chooses to load your javascript and html, what i would recommend is set the element to hidden with css, since that is applied before anything else. And keep you code as is, since the toggle will work anyways

You can also clean up the code a little bit.
<script>
$(document).ready(function(){
$('.content').hide();
$('#toggleMe').click(function(){
$('.content').slideToggle('fast');
});
});
</script>

jQuery slow reveal on page load

I am trying to do a slow reveal on a particular div with an id of 'contentblock' on page load. This is my first time trying to code something in jQuery and I continue to fail. The following is my latest attempt, but I'm a complete newbie to this and surprisingly google hasn't been a whole lot of help.
<script type='text/javascript'>
$(window).onload(function(){
$('#contentblock').slideDown('slow');
return false;
});
</script>
before that I also had the following instead of the window onload line above:
$(document).ready(function(){
But that didn't have any success either. Can someone help a jQuery newbie out?

First, you'll need to make sure the element is hidden (or it won't be shown, since it's already visible). You can do this in either CSS or JavaScript/jQuery:
#contentblock {
display: none;
}
Or:
$('#contentblock').hide();
If you use CSS to hide the element you need to be aware that the element will remain hidden in the event of JavaScript being disabled in the user's browser. If you use JavaScript there's the problem that the element will likely flicker as it's first shown and then hidden.
And then call:
$(window).load(function(){
$('#contentblock').slideDown('slow');
});
I've made two amendments to your jQuery, first I've changed onload to load and I've also removed the return false, since the load() method doesn't expect any value to be returned it serves no purpose herein.
For the above jQuery you can use instead:
$(document).ready(function(){
$('#contentblock').slideDown('slow');
});

$(document).ready(function(){
if($('#contentblock').is(':hidden'))
{
$('#contentblock').slideDown('slow');
}
});
if you have jquery added to your project and your div is display none ... something like this should work.

jQuery inside Media Wiki pages (not just in the Monobook.js or extensions)

I'm trying to do some simple jQuery stuff 'dynamically' from within a MediaWiki content page. Its really just to 'beauty up' some different features.
I've done the following:
http://www.mediawiki.org/wiki/JQuery
http://www.mediawiki.org/wiki/Manual:$wgRawHtml (mainly for Paypal buttons initially)
The below code does not work. This is put in a blank content page.
<html>
<script>
$j(document).ready(function(){
$j('#test').hover(
function(){
$j('#test').attr('background-color','red');
},
function(){
$j('#test').removeAttr('background-color');
}
);
});
</script>
<div id="test">Howdy</div>
</html>
Nothing happens...
Any ideas?
Update:
I have attempted this simple solution with no result.
example.com/wiki/index.php?title=MediaWiki:Common.js
$j('#jTest-Howdy').hover(
function(){
$j('#jTest-Howdy').addClass('jTest-red');
},
function(){
$j('#jTest-Howdy').removeClass('jTest-red');
}
);
example.com/wiki/index.php?title=MediaWiki:Common.css
.jTest-red { background-color: red; }
example.com/wiki/index.php?title=jQueryTest
<html>
<div id="jTest-Howdy">Howdy</div>
</html>
as you can see here, this code should work IF jQuery was being loaded properly...
http://jsfiddle.net/5qFhv/
but it is not working for me... any help?

If you're using the jQuery that's loaded by MediaWiki 1.17, be aware that most JavaScript is loaded after page content. An inline <script> element is executed immediately when it's reached, so $j would not be defined at this time -- you'll probably see some errors in your JavaScript error console to this effect.
(Offhand I'm not sure about the jQuery that's included with 1.16; versions of MediaWiki prior to that as far as I know did not include jQuery.)
Generally what you want to do here is to either put JavaScript code modules into the 'MediaWiki:Common.js' page and let that hook up to your HTML markup, or create a MediaWiki extension -- which you can then invoke from your pages, and which will let you create any fun HTML and JavaScript output you like.
http://www.mediawiki.org/wiki/Manual:Interface/JavaScript
http://www.mediawiki.org/wiki/Manual:Developing_extensions
Code you put in your 'MediaWiki:Common.js' page will be loaded after other UI initialization, ensuring that code and variables are present so you can call into jQuery etc.

I don't know much about MediaWiki, but to me it looks like some simple javascript mistakes.
In the first sample you are trying to set an attribute on the element,
when you need to set the css or style attribute.
$j('#test').css('background-color', 'red');
In both samples you are binding an event to an element that doesn't exist yet in the DOM, so it will fail. You could use the live method, which will work for existing and future elements introduced in the DOM.
$j.('#test').live('mouseover', function(){
$j(this).addClass('hover-class');
}).live('mouseout', function(){
$j(this).removeClass('hover-class');
});
Hope that helps.

Try putting all your custom jQuery code in its own file, then load it as a module with ResourceLoader, after jQuery.
http://www.mediawiki.org/wiki/ResourceLoader/Migration_guide_for_extension_developers
Also, as a debugging method: completely load your site in Firefox, then enter your custom jQuery code in the console. If it works, your problem is a race condition. If it doesn't, jQuery isn't loading for some reason.

Javascript: var is null

I have this piece of Javascript and it just won't work. I allready checked JSlint but that said everything works. Still doesn't work. The javascript is located not in the HTML but is linked in the <head>
note: I am working with a local server, so pageload in instant.
function changeVisibility() {
var a = document.getElementById('invisible');
a.style.display = 'block';
}
var changed = document.getElementById('click1');
changed.onchange = changeVisibility;
This here is the corresponding HTML
<input type="file" name="click[]" size="35" id="click1" />
<div id="invisible" style="display: none;">
Attach another File
</div>
So what happens is I click on the input, select a file and approve. Then then onchange event triggers and the style of my invisible div is set to block.
Problem is, I keep getting this error:
"changed is null:
changed.onchange = changeVisibility;"
i don't get it, I seriously don't get what I'm overlooking here.
EDIT: question answered, thank you Mercutio for your help and everyone else too of course.
Final code:
function loadEvents() {
var changed = document.getElementById('click1');
var a = document.getElementById('invisible');
document.getElementById('addField').onclick = addFileInput;
changed.onchange = function() {
a.style.display = 'block';
}
}
if (document.getElementById) window.onload = loadEvents;
This here is the corresponding HTML:
<input type="file" name="click[]" size="35" id="click1" />
<div id="invisible" style="display: none;">
Attach another File
</div>
Also, thanks for the link to JSbin, didn't know about that, looks nifty.

This sounds like the DOM object doesn't exist at the time of referencing it. Perhaps change your code to execute once the document has fully loaded (or place the javascript at the bottom of your page)
note: I am working with a local server, so pageload in instant.
that's not the issue - the constituent parts of a document are loaded in order. It doesn't matter how fast they are loaded, some things happen before others :D
The onlything I'd like to do now is remove the Javascript link from the ...
Place an id on there, and inside your function do this:
document.getElementById('addField').onclick = addFileInput;
Or, as you already have the div as the variable 'a':
a.firstChild.onclick = addFileInput;
But this obviously leaves you with an invalid anchor tag. Best practice suggests that you should provide a way to do it without javascript, and override that functionality with your javascript-method if available.

mercutio is correct. If that code is executing in the HEAD, the call to "document.getElementById('click1')" will always return null since the body hasn't been parsed yet. Perhaps you should put that logic inside of an onload event handler.

I think its because you are trying to modify a file element.
Browsers don't usually let you do that. If you want to show or hide them, place them inside of a div and show or hide that.

Right, I've modified things based on your collective sudgestions and it works now. Onlything bothering me is the direct reference to Javascript inside the anchor

You need to wrap your code in a window.onload event handler, a domReady event handler (available in most modern js frameworks and libraries) or place at the bottom of the page.
Placing at the bottom of the page works fine, as you can see here.
Decoupling event responder from your markup is covered under the topic of "Unobtrusive JavaScript" and can be handled in a variety of ways. In general, you want to declare event responders in a window.onload or document.ready event.