Develop Reference

is this javascript code correct?

I am trying to remove a class when clicking on an element with a specific class. I made this javascript and it does work. But is this correct syntax to do it this way Can this be more efficient?
// Clear notifications alerts
$(document).on('click', '.js-clear-notifications', function() {
$('.AlertNotifications').remove();
});
// clear inbox alerts
$(document).on('click', '.js-clear-inbox', function() {
$('.AlertInbox').remove();
});

Your javascript code is correct, provided that you load jQuery as well.
Furthermore you have the most efficient solution, where you use a single event handler to handle events that originate on multiple elements.
The alternative would be:
$('.js-clear-notifications').on('click', function() {
$('.AlertNotifications').remove();
});
Which attaches as many event handlers as there are elements in the jQuery object. Slightly less efficient, though probably you would never notice except in extreme cases.

To me a more proper way to do it is something like this:
...
$('.js-clear-inbox').on('click', function() {
$('.AlertInbox').remove();
});
...
I will also suggest to have more specific selectors i.e.
$('div .js-clear-inbox')
I hope that this helps.

I am editing this in response to the feedback in the comments.
If what you want is to remove all elements with AlertNotifications class, which is what your code does, then what you have is correct.
If what you want is to remove only the class, which is what the text of the post said, you want removeClass, not remove:
$('.js-clear-notifications').on('click',function() {
$(this).removeClass('AlertNotificitions');
}

The new way, if you have already defined the variable, the proper way to delete it from the DOM would be:
var elem = document.getElementById("myDiv");
elem.remove();
But if you are just beginning out, .remove would be your best opinion.

Devil of a time with jQuery delegate and .not

I've searched hi and low but couldn't find a solution. I've tried everything.. but can't get this thing to work.
NOTE: Can't use ".on()" . Using an older version of jQuery that only supports .live/.delegate
basically, I have a very involved webpage.. and there are event handlers flying everwhere.. BUT, I basically want to attach a click event on the body BUT exclude certain id's. Great. Figured it would be easy.
tried:
jQuery('body').delegate('.not("#mainID #anotherID")','click', function(e){
// do something
})
jQuery('body').delegate(':not(".class1 .class2")','click', function(e){
// do something
})
etc...
and a bunch bunch more.. basically, cannot get this thing to work. No matter what I do, the whole page is clickable.
when I do something simple like: Great it works.
jQuery('body').delegate('#someID','click', function(e){
// do something
})
But that isn't what i need. I need to basically allow for clicking on the whole body except for two subsets, smaller sections of the page. I figured this would be trivial.. but for some reason, just not working.
The two items I want to exclude are:
id: mainID w/ a class of ".class1"
id: anotherID w/ a class of ".class2"
another note: mainID sits outside of anotherID - two distinct sections of the page. Both divs.

Let me point out few things related to event delegation:
First of all, use .on() function, .delegate() is deprecated.
Second, .class1 .class2 will match class2 which is inside of class1
jQuery('body').on('click', ':not(.class1, .class2)', function(e) {
// do something
})
But, this is also not what you need, you need:
$(".class1, .class2").on('click', function() { return false; });
If you are using older versions of jQuery and for some reason cannot change it, use .live() or normal .click() handler:
$(".class1, .class2").click(function() { return false; });
Now, if you click on .class1 and .class2 nothing will happen. If you want to select only specific class within a id you can use #mainID .class1 as selector. Or with older event delegation:
jQuery('body').delegate(':not(.class1, .class2)','click', function(e){
// do something
// but this will execute on every where you click except .class1, .class2
})

jQuery select all elements with a common class

I want to handle a click event across a set of links so tried to approach this by adding a secondary class like following:
Test 1
Test 2
Test 3
Don't handle this one
Then tried this jquery selector to select the "external" class on links:
$('a.external').click(function(e) {
do something here...
});
However this isn't working like I expected. What's the right way to handle this? Should I just use a wildcard selector like the following or is there a better way?
$('[class^="someclass"]').click(function(e) {
....
});

What you have is exactly right (though the e probably isn't necessary in function(e) in your case).
Test 1
Test 2
Test 3
Don't handle this one
<script>
$('a.external').click(function(e) {
// will print the href in a javascript alert box
alert( $(this).attr('href') );
});
</script>
As far as I can tell the only possibility is that your <script> is actually above your <a> tags -- your script can't add the click listeners to the anchors because they wouldn't exist yet.
If so, you'll need to wrap the javascript in $(document).ready( function(){ /* code here */ });
Also, no need for the external class, just use the "select all absolute anchors, but not the ones linking to my domain" selector: $('a[href^="http://"]').not('[href^="http://mydomain.com"]')

I'm going to guess that your issue is that clicking the links actually makes it navigate somewhere? You need to tell the browser to ignore the normal link behavior. Otherwise your click function will run and then it will immediately navigate to the 'href' url. Also make sure this is all wrapped in a ready function.
$(function() {
$('a.external').click(function(e) {
// Do whatever
e.preventDefault();
});
});

I tried it out in jsFiddle and it works.
You have an extra parenthesis on the click() function.
Notice have your function(e) you have close parenthesis, remove that.
You should end up with this:
$('a.external').click(function(e) {
do something here...
});

try : http://jsfiddle.net/n6JJ3/
$('a.external').click(function() {
jQuery(this).css('background','red');
});​

Do I have to duplicate this function? - jQuery

I'm using this function to create an transparent overlay of information over the current div for a web-based mobile app.
Background: using jQTouch, so I have separate divs, not individual pages loading new.
$(document).ready(function() {
$('.infoBtn').click(function() {
$('#overlay').toggleFade(400);
return false;
});
});
Understanding that JS will run sequentially when i click the button on the first div the function works fine. When I go to the next div if I click the same button nothing "happens" when this div is displayed, but if i go back to the first div it has actually triggered it on this page.
So I logically duplicated the function and changed the CSS selector names and it works for both.
But do I have to do this for each use? Is there a way to use the same selectors, but load the different content in each variation?

Would something like this work? I'm assuming what you want is for different buttons to call toggleFade on different overlay divs.
function makeOverlayHandler(selector) {
return function() {
$(selector).toggleFade(400);
return false;
}
}
$('button selector').click(makeOverlayHandler('#overlay1'));
$('another button selector').click(makeOverlayHandler('#overlay2'));
You could also change makeOverlayHandler's selector parameter to a jQuery object instead of a selector and call it like this: makeOverlayHandler($('#overlay1')).

This best way to do this is to make it all relative, so say you have markup like this:
<div class="container">
<div class="overlay">Overlay content</div>
<button class="infoBtn">Click to show overlay</button>
</div>
Then you can find the overlay for this button realtively, like this:
$(function() { //equivalent to $(document).ready(function() {
$('.infoBtn').click(function() {
$(this).closest('.container').find('.overlay').toggleFade(400);
return false;
});
});
You can optimize this further, e.g. .children('.overlay') if the overlay is always a direct child of container. This goes from the current button (this), finds the .container it's in using .closest() and then finds the .overlay inside of it using .find(). With this approach you have one small bit of code to handle all your bindings, much easier to maintain :)

Javascript + jQuery, click handler returning false to stop browser from following link

I'm trying to stop the browser from following certain links, rather I want to unhide some Divs when they are clicked.
I'm having trouble just getting the links to not be followed though.
Here's what I have:
var titles = $('a.highlight');
jquery.each(titles, function(){
this.click(function(){
return false;
});
});
It seems like the click handler is not being assigned. What am I missing?

Try
this.click(function(e){ e.preventDefault(); }
Actually, it looks like you might need to use the jQuery constructor on this:
$(this).click(function(){ return false; }
You could also try using parameters on the each function instead of using this:
jQuery.each( titles, function(index, elem) { $(elem).click( function() { return false; } ) } );
Personally, I would just do titles.each( ... though. In that instance you can use this to bind the click handler. I am not sure off the top of my head what this binds to with jQuery.each
Or just calling click on titles:
titles.click( function() { return false; } )
That will bind click to every element in titles. You don't need to loop through them.

You can compress that jquery a bit:
$('a.highlight').click(function() { return false; });
You should also make sure that:
There are no other click handlers registered for those elements later on.
The code you have is attaching after the elements have loaded. If they're not completely loaded, they won't be found in the $('a.highlight') selector. The easiest way to do this is to put your code in a $(document).ready(function() { *** code here *** }); block.
Edit: As per other responses - the problem was that this represents a DOM object, while $(this) is a jquery object. To use the .click function to attach a handler, you need a jquery object.
In short, using this inside the each loop won't work with what you're trying to do. You'll need to get a jquery representation by using $(this) instead.