Drop Down Box keeps scrolling up - javascript

I implemented this to my site from an earlier question but for some reason on Firefox and IE the drop-down box scrolls up by itself. I can't figure out why!
Just click News Feed and as the box drops down, it automatically drops up. It's supposed to drop down and if I click on newfeed again or outside, it's supposed to drop up. But it doesn't do that, it just springs back up.
I am using the JavaScript. What is going on here?
$('#bottom').click(function() {
$('#content').slideDown();
});
$(document).click(function(e) {
if (e.target.id !='bottom') {
$('#content').slideUp();
}
});

Change your #bottom event handler a bit to prevent the bubbling of the click event all the way up to the document:
//it is important to declare the `event` variable as a parameter of this anonymous function so it can be accessed inside the function
$('#bottom').click(function(event) {
event.stopPropagation();
$('#content').slideDown();
});
What's happening with your code is that the event handler for the #bottom element is being triggered, then after that the event handler for clicking on the document fires since the click event bubbles up the DOM. event.stopPropagation() will stop the event from bubbling.
Docs for event.stopPropagation(): http://api.jquery.com/event.stoppropagation/

Related

Catching click event while delete thumbnail

I slightly modified FU thumbnail template to hook a click event on it. I also display a delete button (the provided one).
The problem is that when I click on the delete button, the click event bubbles to the rest of the javascript stack.
How can I prevent the delete button to propagate the click event??
(usually you do something like event.stopPropagation()...).
Thanks for your help
If you'd like to prevent any DOM event from bubbling, simply attach an event handler to the element where you would like it to terminate and call stopPropagation() on the Event object. For example, for a click event:
someElement.addEventListener('click', function(event) {
event.stopPropagation();
});
The above code will not work in IE8 and older since addEventListener and stopPropagation were first introduced in IE9.

scrollIntoView() preventing other listeners from triggering

I am using scrollIntoView() on an event target to ensure it is visible in its parent which has overflow: scroll, this is mainly for accessibility reasons.
My problem is that I also have click events associated with this element and when a click event also fires the focus e.target.scrollIntoView() is preventing other events from firing.
This is my current example:
http://jsfiddle.net/omhuorpr/
require([
"dojo/query",
"dojo/on"
], function(query, on){
var el = query('#someElement');
el.on('click', function(e){
e.preventDefault();
console.log("clicked");
});
el.on('focus', function(e){
console.log("focus");
e.target.scrollIntoView();
});
});
If you click on the element and check the console it will only fire the focus, if you re-click it then fires the click. Ideally I want to fire both at the same time or just the click.
A simple fix that works is to move this process to the end of the execution stack via a timeout however ideally I want to find out why scrollIntoView() is preventing other events from firing.
It's because the focus event fires on mouse down, and the click event fires on mouse up. If the element has scrolled so that the mouse pointer is no longer over the element by the time you release the button, the click event won't fire. However, if the mouse pointer is still over the element after the scroll, the click will fire.
If you increase the font size in your fiddle and click near the top, you'll see the click fire. If you click near the bottom and the element scrolls out from under the pointer, the click event won't fire. E.g.
#someElement {
font-size:80px;
}
http://jsfiddle.net/omhuorpr/1/

An object binded with .click(function() {...}); has no effect on click

I'm trying to bind to a span element a function to scroll a slideshow (specifically rcarousel plugin).
that's the javascript code:
$('.forward').click(function() {
$("#carousel").rcarousel("next");
});
$('.rewind').click(function() {
$("#carousel").rcarousel("goToPage", 0);
});
Now, this code is inside a document.ready function, the forward button $(".forward") works and successfully scrolls the slideshow, but it's like the rewind button being totally ignored by the browser. With no errors thrown by the chrome devtools console; and if I paste the same code in the console .rewind starts magically to work.
Anyone knows what kind of sorcery is going on there?
PS: In the same document.ready function there are other bindings, each working flawlessly
The carousel buttons are changed dynamically by the carousel, so you need to use a delegated event handler, attached to a non-changing ancestor (document is the default of nothing closer is handy):
$(document).on('click', '.forward', function() {
$("#carousel").rcarousel("next");
});
$(document).on('click', '.rewind', function() {
$("#carousel").rcarousel("goToPage", 0);
});
Delegated events work by listening for the event to bubble up to a non-changing ancestor, then applying the jQuery selector, then applying the function to any clicked elements that caused the event. This means that the element only need to match at event time, not *event registration time).
Note: Do not connect delegated event handlers to 'body' as styling can cause body to have a zero height and not respond to bubbled mouse events.

Blur event stops click event from working?

It appears that the Blur event stops the click event handler from working? I have a combo box where the options only appear when the text field has focus. Choosing an option link should cause an event to occur.
I have a fiddle example here: http://jsfiddle.net/uXq5p/6/
To reproduce:
Select the text box
Links appear
Click a link
The blur even occurs and the links disappear
Nothing else happens.
Expected behavior:
On step 5, after blur occurs, the click even should also then fire. How do I make that happen?
UPDATE:
After playing with this for a while, it seems that someone has gone to great lengths to prevent an already-occurred click event from being handled if a blur event makes the clicked element Un-clickable.
For example:
$('#ShippingGroupListWrapper').css('left','-20px');
works just fine, but
$('#ShippingGroupListWrapper').css('left','-2000px');
prevents the click event.
This appears to be a bug in Firefox, since making an element un-clickable should prevent future clicks, but not cancel ones that have already occurred when it could be clicked.
Other things that prevent the click event from processing:
$('#ShippingGroupListWrapper').css('z-index','-20');
$('#ShippingGroupListWrapper').css('display','none');
$('#ShippingGroupListWrapper').css('visibility','hidden');
$('#ShippingGroupListWrapper').css('opacity','.5');
I've found a few other questions on this site that are having similar problems. There seem to be two solutions floating around:
Use a delay. This is bad because it creates a race condition between the hiding and the click event handler. Its also sloppy.
Use the mousedown event. But this isn't a great solution either since click is the correct event for a link. The behavior of mousedown is counter-intuitive from a UX perspective, particularly since you can't cancel the click by moving the mouse off the element before releasing the button.
I can think of a few more.
3.Use mouseover and mouseout on the link to enable/disable the blur event for the field. This doesn't work with keyboard tabing since the mouse is not involved.
4.The best solution would be something like:
$('#ShippingGroup').blur(function()
{
if($(document.activeElement) == $('.ShippingGroupLinkList'))
return; // The element that now has focus is a link, do nothing
$('#ShippingGroupListWrapper').css('display','none'); // hide it.
}
Unfortunately, $(document.activeElement) seems to always return the body element, not the one that was clicked. But maybe if there was a reliable way to know either 1. which element now has focus or two, which element caused the blur (not which element is blurring) from within the blur handler. Also, is there any other event (besides mousedown) that fires before blur?
click event triggers after the blur so the link gets hidden. Instead of click use mousedown it will work.
$('.ShippingGroupLinkList').live("mousedown", function(e) {
alert('You wont see me if your cursor was in the text box');
});
Other alternative is to have some delay before you hide the links on blur event. Its upto you which approach to go for.
Demo
You could try the mousedown event instead of click.
$('.ShippingGroupLinkList').live("mousedown", function(e) {
alert('You wont see me if your cursor was in the text box');
});
This is clearly not the best solution as a mousedown event is not achieved the same way for the user than a click event. Unfortunately, the blur event will cancel out mouseup events as well.
Performing an action that should happen on a click on a mousedown is bad UX. Instead, what's a click effectively made up of? A mousedown and a mouseup.
Therefore, stop the propagation of the mousedown event in the mousedown handler, and perform the action in the mouseup handler.
An example in ReactJS:
<a onMouseDown={e => e.preventDefault()}
onMouseUp={() => alert("CLICK")}>
Click me!
</a>
4.The best solution would be something like:
$('#ShippingGroup').blur(function()
{
if($(document.activeElement) == $('.ShippingGroupLinkList'))
return; // The element that now has focus is a link, do nothing
$('#ShippingGroupListWrapper').css('display','none'); // hide it.
}
Unfortunately, $(document.activeElement) seems to always return the
body element, not the one that was clicked. But maybe if there was a
reliable way to know either 1. which element now has focus or two,
which element caused the blur (not which element is blurring) from
within the blur handler.
What you may be looking for is e.relatedTarget. So when clicking the link, e.relatedTarget should get populated with the link element, so in your blur handler, you can choose not to hide the container if the element clicked is within the container (or compare it directly with the link):
$('#ShippingGroup').blur(function(e)
{
if(!e.relatedTarget || !e.currentTarget.contains(e.relatedTarget)) {
// Alt: (!e.relatedTarget || $(e.relatedTarget) == $('.ShippingGroupLinkList'))
$('#ShippingGroupListWrapper').css('display','none'); // hide it.
}
}
(relatedTarget may not be supported in older browsers for blur events, but it appears to work in latest Chrome, Firefox, and Safari)
If this.menuTarget.classList.add("hidden") is the blur behavior that hides the clickable menu, then I succeeded by waiting 100ms before invoking it.
setTimeout(() => {
this.menuTarget.classList.add()
}, 100)
This allowed the click event to be processed upon the menuTarget DOM before it was hidden.
I know this is a later reply, but I had this same issue, and a lot of these solutions didn't really work in my scenario. mousedown is not functional with forms, it can cause the enter key functionality to change on the submit button. Instead, you can set a variable _mouseclick true in the mousedown, check it in the blur, and preventDefault() if it's true. Then, in the mouseup set the variable false. I did not see issues with this, unless someone can think of any.
I have faced a similar issue while using jQuery blur, click handlers where I had an input name field and a Save button. Used blur event to populate name into a title placeholder. But when we click save immediately after typing the name, only the blur event gets fired and the save btn click event is disregarded.
The hack I used was to tap into the event object we get from blur event and check for event.relatedTarget.
PFB the code that worked for me:
$("#inputName").blur(function (event) {
title = event.target.value;
//since blur stops an immediate click event from firing - Firing click event here
if (event.relatedTarget ? event.relatedTarget.id == "btnSave" : false) {
saveBtn();
}
});
$("#btnSave").click(SaveBtn)
As already discussed in this thread - this is due to blur event blocking click event when fired simultaneously. So I have a click event registered for Save Btn calling a function which is also called when blur event's related Target is the Save button to compensate for the click event not firing.
Note: Didnt notice this issue while using native onclick and onblur handlers - tested in html.

event.preventDefault() and multiple events

Before I start writing huge swathes of code that don't work I thought I'd ask this question.
event.preventDefault() only cancels the default action of the click event doesn't it?
Theoretically I should be able to bind mutiple click event handlers in jQuery to a given target to perform different actions like Ajax posts and Google tracking.
Am I wrong?
event.preventDefault() only cancels the default action of the click event doesn't it?
It cancels the browser's default action of the event (not just the click event) (W3C docs, jQuery docs). So for instance, in the form submit event, it prevents the form being submitted by the browser. It doesn't stop anything you're doing in code, and it doesn't stop bubbling; that's what stopPropagation is for (W3C docs, jQuery docs).
So say you have a link in a div, and you have the click event hooked on both the link and the div. If the link's event handler calls preventDefault, the browser won't do its default action (following the link), but the event continues to bubble up the DOM to the link's parent element, the div, and so you'll see the event on your click handler there, too. Any actions you're taking in code in either handler will be unaffected by your calling preventDefault.
In your comment below, you ask about multiple handlers on the same element. Neither preventDefault nor stopPropagation affects those, they'll still get fired...unless you use stopImmediatePropagation, which tells jQuery to stop the event dead in its tracks (but doesn't prevent the browser's default action).
I should probably round this out by saying that if you return false from your event handler, that tells jQuery to prevent the default and stop bubbling. It's just like calling preventDefault and stopPropagation. It's a handy shortcut form for when your event handler is taking full control of the event.
So, given this HTML:
<div id='foo'><a href='http://stackoverflow.com'>Q&A</a></div>
Example 1:
// Here we're preventing the default but not stopping bubbling,
// and so the browser won't follow the link, but the div will
// see the event and the alert will fire.
$("#foo").click(function() {
alert("foo clicked");
});
$("#foo a").click(function(event) {
event.preventDefault();
});
Example 2:
// Here we're stopping propagation and not preventing the default;
// the browser will follow the link and the div will not be given
// a chance to process the event (no alert, and more to the point,
// code in the div's handler can't prevent the default)
$("#foo").click(function() {
alert("foo clicked");
});
$("#foo a").click(function(event) {
event.stopPropagation();
});
Example 3 (you'll only rarely see this):
// Here we're doing both, and so the browser doesn't follow the
// link and the div doesn't see the event (no alert).
$("#foo").click(function() {
alert("foo clicked");
});
$("#foo a").click(function(event) {
event.preventDefault();
event.stopPropagation();
});
Example 4:
// Shorter version of Example 3, exactly the same effect
$("#foo").click(function() {
alert("foo clicked");
});
$("#foo a").click(function() {
return false;
});

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