We Keep Coding

Prototype toggle - two instances getting muddled

I have two instances that use the toggle(). So in the code there is this link:
Completely independent link
Followed by a more complex show hide toggle area:
Show All
And then the reverse of that:
Show Less
The problem I have is when I toggle the "Show all" link - it renders the "Completely Independent link" unusable. Sometimes it even opens shows/hides #div1?!?
Not really sure what is going on but the two instances are definitely getting muddled up.

I think what is happening is your click event is bubbling up the DOM and it hits other elements - but I can't be sure without seeing more of your HTML structure.
That being said - I would suggest putting everything in separate click observers, it removes the javascript from the HTML, and makes it easier to handle.
For example your 3 links
Completely independent link
Show All
Show Less
would change to
Completely independent link
Show All
Show Less
and add this in your head or js file or somewhere on your page
<script>
document.observe('dom:loaded', function()
$('link1').observe('click',function(){
$('div1').toggle();
});
$('showall').observe('click',function(){
$('showLessInfo').toggle();
$('showAllInfo').toggle();
$('showAllInfoLink').toggle();
});
$('showless').observe('click',function(){
$('showLessInfo').toggle();
$('showAllInfo').toggle();
$('showAllInfoLink').toggle();
});
});
</script>
Now for extra bonus, I changed the href="#" to href="javascript:void(0);" to avoid the need to stop the event.

Dude, your selectors are all messed up.
You can't just use $('div1'), because that won't return anything. If it's a class use $('.div1') and if it's an id use use $('#div1').
Also maybe avoid writing your handlers inline, it's much harder to read and notice possible errors. Just put all of that in a seperate javascript file.

jQuery UI Dialog: Dialog Element Disappearing from the DOM

I'm working on a project and I am attempting to create a modal dialog "pop-up" to capture data in a form. I haven't worked with jQuery UI's Dialog widget previously, but I've worked with others and it seemed straight forward.
I created the following very simple code snippet to test as I went along:
<div class="app-email">
<div>
<a href="#"
class="app-email-opener">
Click to add or edit your e-mail settings.
</a>
</div>
<div class="app-email-modal">
Oh, Hai.
</div>
</div>
$('.content').on({
click: function () {
console.log('I was totes clicked.');
var parent = $(this).parents('.app-email');
console.log(parent);
var target = parent.find('.app-email-modal');
console.log(target);
$(target).dialog('open');
}
}, '.app-email-opener');
$('.app-email-modal').dialog({
autoOpen: false,
modal: true,
show: false
});
For reference: the class 'content' is a higher level block to catch delegated events without having to go all the way up the DOM.
The issue I'm running into is that the div with class="app-email-modal" seems to flash onto the page and then disappear from the DOM completely. jQuery, therefore, isn't able to find it and do anything because at that point it simply doesn't exist.
The overall project is in ASP.NET MVC 4, using Visual Studio 2013.
Any information would be greatly appreciated.

So, finally discovered what's happening via this previously answered question:
Jquery Dialog - div disappears after initialization
//EDIT
For any possible future usefuless -
What was happening was that jQuery UI will move any DOM elements specified as Dialogs to the bottom of the page, rather than keep them in the location specified in the HTML markup. So, in my case, I was looking for things by class, but only within the scope of the app-email-openers parent app-email div.
To remedy this, I used templating (in my case, Razor) to add unique ids to each app-email-modal div, and added a data- attribute to associate the link with the specific unique id. This way they jQuery UI can move the elements as it sees fit, but there still easily accessible.
//END EDIT
I feel like that functionality should be better spelled out in the documentation. Even their own example doesn't operate like this.
Corollary: I attempted to use the appendTo option to have the DOM elements not be shifted to the bottom of the page, but they're still moved to the bottom. So, there's that.

Javascript: Page reloads with eventListener click

In trying to understand javascript best practices, I'm attempting to recreate a piece of inline javascript by adding an event listener from an external javascript file.
The inline code works fine and looks like this:
<p id="inline" align="left">
This is a body paragraph which changes alignment
when a user clicks on a link below
</p>
<p>
Align Right
</p>
Concerning my problem, the important thing to note here is that return false; prevents the page from reloading (I'm not actually sure why, and wouldn't mind finding out, especially if it relates to the solution to my problem...). This is what I want. I don't need the page to reload to move the text to the right.
However, I have no idea what the best way to keep the page from reloading is when my javascript is in an external file. Here's what my first attempt looks like. I started with html that looks like this:
<p id="external" align="left">
This is a body paragraph which changes alignment
when a user clicks on a link below. It uses an
external .js file.
</p>
<p>
Align Right
</p>
And javascript that looks like this:
function alignListener () {
document.getElementById('external').setAttribute('align', 'right');
}
function installListeners () {
var aRight = document.getElementById('aRight');
aright.addEventListener('click', alignListener, false);
}
This almost works, but not at all how I would expect. When I click on the 'Align Right' link, the text briefly aligns right, but then, I follow the link to the current page, which resets the alignment back to the left.
I found a way to sort of fix that problem, by using <a href="#" ... instead of <a href="" .... While this doesn't reload the page (so the text stays aligned), it does take me to the top, which isn't really what I want. I'd like a solution similar to the return false; that works with the inline javascript. Is there a simple way to do this? Or am I doing it wrong completely?

I highly recommend the mozilla developer network for most of these types of answers. It's easy to read and will help you understand JavaScript and the DOM. (JavaScript is good!, DOM is awkward...)
Specifically, for events: https://developer.mozilla.org/en/DOM/event
In general, https://developer.mozilla.org/
There are a few ways to stop events, preventDefault(), stopPropagation(), return false;, or use a JavaScript framework as suggested above. jQuery is good, there are many many others out there (YUI, Dojo, MooTools, etc.), and they all endeavor to make your JavaScript more compatible with different browsers.

Use <button> instead of <a> tag.
That helped me.

You can use:
function event(e){
var e=window.event||e;
//do stuff
if(e.preventDefault){e.preventDefault()}else{e.returnValue=false}
}
Note that this doesn't need to go on a new function: .addEventListener("click",function(e){/*the above function*/})
Cross-compatible event listener:
if(element.addEventListener){
element.addEventListener(eventName, function, false);
}else{
element.attachEvent("on"+eventName, function);
}

JQuery: Why is hoverIntent not a function here?

I'm modifying some code from a question asked a few months ago, and I keep getting stymied. The bottom line is, I hover over Anchors, which is meant to fade in corresponding divs and also apply a "highlight" class to the Anchor. I can use base JQuery and get "OK" results, but mouse events are making the user experience less than smooth.
I load JQuery 1.3 via Google APIs.
And it seems to work. I can use the built in hover() or mouseover(), and fadeIn() is intact... no JavaScript errors, etc. So, JQuery itself is clearly "loaded". But I was facing a problem that it seemed everyone was recommending hoverIntent to solve.
After loading JQuery, I load the hoverIntent JavaScript. I've triple-checked the path, and even dummy-proofed the path. I just don't see any reasonable way it can be a question of path.
Once the external javascripts are (allegedly) loaded in, I continue with my page's script:
var $old=null;
$(function () {
$("#rollover a").hoverIntent(doSwitch,doNothing)
});
function doNothing() {};
function doSwitch() {
var $this = $(this);
var $index = $this.attr("id").replace(/switch/, ""); //extract the index number of the ID by subtracting the text "switch" from its name
if($old!=null) $old.removeClass("highlight"); //remove the highlight class from the old (previous) switch before adding that class to the next
$this.addClass("highlight"); //adds the class "highlight" to the current switch div
$("#panels div").hide(); //hide the divs inside panels
$("#panel" + $index).fadeIn(300); //show the panel div "panel + number" -- so if switch2 is used, panel2 will be shown
$old = $this; //declare that the current switch div is now "old". When the function is called again, the old highlight can be removed.
};
I get the error:
Error: $("#rollover a").hoverIntent is not a function
If I change to a known-working function like hover (just change ".hoverIntent" to ".hover") it "works" again. I'm sure this is a basic question but I'm a total hack when it comes to this (as you can see by my code).
Now, for all appearances, it SEEMS like either the path is wrong (I've zillion-checked and even put it on an external site with an HTTP link that I double-checked; it's not wrong), or the .js doesn't declare the function. If it's the latter, I must be missing a few lines of code to make the function available, but I couldn't find anything on the author's site. In his source code he uses a $(document).ready, which I also tried to emulate, but maybe I did that wrong, too.
Again, the weird bit is that .hover works fine, .hoverIntent doesn't. I can't figure out why it's not considered a function.
Trying to avoid missing anything... let's see... there are no other JavaScripts being called. This post contains all the Javascript the page uses... I tried doing it as per the author's var config example (hoverIntent is still not a function).
I get the itching feeling I'm just missing one line to declare the function, but I can't for the life of me figure out what it is, or why it's not already declared in the external .js file. Thanks for any insight!
Greg
Update:
The weirdest thing, since I'm on it... and actually, if this gets solved, I might not need hoverIntent solved:
I add an alert to the "doNothing" function and revert back to plain old .hover, just to see what's going on. For 2 of my 5 Anchors, as soon as I hover, doNothing() gets called and I see the alert. For the other 3, doNothing() correctly does NOT get called until mouseout. As you can see, the same function should apply for any Anchor inside of "rollover" div. I don't know why it's being particular.
But:
If I change fadeIn to another effect like slideDown, doNothing() correctly does NOT get called until mouseout.
when using fadeIn, doNothing() doesn't get called in Opera, but seems to get called in pretty much all other browsers.
Is it possible that fadeIn itself is buggy, or is it just that I need to pass it an appropriate callback? I don't know what that callback would be, if so.
Cheers for your long attention spans...
Greg

Hope I didn't waste too many people's time...
As it turns out, the second problem was 2 feet from the screen, too. I suspected it would have to do with the HTML/CSS because it was odd that only 2 out of 5 elements exhibited strange behaviour.
So, checked my code, dug out our friend FireBug, and discovered that I was hovering over another div that overlapped my rollover div. Reason being? In the CSS I had called it .panels instead of .panel, and the classname is .panel. So, it used defaults for the div... ie. 100% width...
Question is answered... "Be more careful"
Matt and Mak forced me to umpteen-check my code and sure enough I reloaded JQuery after loading another plugin and inserting my own code. Since hoverIntent modifies JQuery's hover() in order to work, re-loading JQuery mucked it up.
That solved, logic dictated I re-examine my HTML/CSS in order to investigate my fadeIn() weirdness... and sure enough, I had a typo in a class which caused some havoc.
Dumb dumb dumb... But now I can sleep.

jquery ui.slider: add click event to display/hide handle

I am completely new to javascript and jquery. My programming knowledge is... nonexistent, I just started some days ago with some simple tasks like replacing a CSS class or toggling a div. So I want to apologize if I'm treading on someones toes by asking newbie-questions in here. But I hope that someone can help me and solve my problem.
I need to implement some sort of visual analog scale for a survey; ui.slider is perfect for that one. But I need the handle to be hidden by default. When the user clicks on the slider, the handle shall appear in the proper position. That should be fairly simple - at least I hope so - by just hiding the handle with CSS and changing it by a click event on the slider.
I use the following piece of code to wrap a normal div (a div is needed in my understanding to apply the jquery slider.js) to my input elements (they should be - at least visually - replaced by the slider) and pass the value of the slider to the input elements (needed for passing the values to a form). that works properly. (I do that instead of just putting a div in my DOM by default because I cannot influence some PHP scripts that will generate form elements of the survey and so on)
$(function () {
$.each($('.slider'),
function () {
obj = $(this);
obj.wrap('<div></div>');
obj.parent().slider({
change: function (event, ui) {
$('input', this).val(ui.value);
}
});
});
});
Hiding the slider-handle can be done by CSS as described above by changing style properties of a.ui-slider-handle. but when I add a normal click event to the slider (.ui-slider) that changes CSS properties of the handle, nothing happens. As far as my basic knowledge goes it should have something to do with the click event not working on generated DOM elements. Am I right with that one? And if yes: how can I solve this problem? Could someone provide me a piece of code for my function and explain it so I might comprehend what's exactly going on?
I read a tutorial about events on learningjquery.com but I have not made enough progresses the last few days since I started working with JS/jquery to comprehend the steps and translate it into my example/problem. And I am running out of time (I need this for a survey I have to make asap, that's why I hope someone could give me a hint so I can solve this little issue somehow).

Any reason you can't just include the show on the change event rather than a click? It's a bit cleaner code-wise rather than including a whole new event.
$(function() {
$('.slider').wrap('<div></div>').parent().slider({
change: function(event, ui) {
$('input', this).val(ui.value);
$('.ui-slider-handle').show();
}
});
});
Also, there was a bit of redundancy in the code - most jQuery functions return the object itself, so you can chain them. And you don't need that each function, since most jQuery functions also, when applied to a collection, run on all of them :)