I have created a small jQuery plugin that creates sticky sidebars and I've tried to create a "destroy" method which removes the stickyness. It works fine however I'm using it on multiple elements on the page (sticky sidebar within accordions) and when I destroy one, it removes the scroll events for all the others.
$parent.find('.js-opps-aside').stickAside();
var thisScroll = $(window).on('scroll', enqStick);
...
$(window).off('scroll', thisScroll);
I thought that was how to unbind specific scroll events, however, as I said it removed all the event handlers. I just want it to remove the scroll event for this specific element it was called upon, and leave the other elements with their scroll events intact.
When you use $().off(), the second parameter is a reference to the event handler, and you try to off with thisScroll but it is a jQuery collection.
You should use this :
$(window).off('scroll', enqStick);
You can use another solution that is think is better, just suffit the event name
$parent.find('.js-opps-aside').stickAside();
$(window).on('scroll.myCustomScroll', enqStick);
...
$(window).off('scroll.myCustomScroll');
$().off with only one parameter will off all event callbacks associated with the event, in our case it will of all scroll.myCustomScroll
According to jQuery stacking logic thisScroll is $(window).
What you would like to do is:
// Binding a handler
$(window).on('scroll', enqStick);
// removing handler by bound function handler
$(window).off('scroll', enqStick);
Related
I have the falling events hash -
events:
'click #someButton : 'someFunction'
To close the view I have tried
close:
$("#someButton").unbind("click")
and
`close:
$("#someButton").remove()`
But someFunction is still being fired more than once. How do I unbind this event from the button?
I've also tried
$(#el).find("#someButton").unbind("click") as well
Backbone.js view events are delegated to the view's el (so there is no event bound to your #someButton element but rather when a click event bubbles up to the el it checks to see if the event came from an element matching that selector), that being the case to remove the event you need to remove it from the el, for example
$(this.el).off('click', '#someButton');
If you want to remove all delegated events you can just use the view's undelegate method
Jack's explanation and answer are great. Unfortunately, his code example didn't work for me. Instead of using:
$(this.el).off('click', '#someButton');
I had to use:
this.$el.off('click', '#someButton');
which makes sense to me, because the event was bound to this.$el object.
To add further, I used this.$el.off(); inside an initialize within a subview to destroy all events tied to the subview. The same event would fire X number of times a data refresh was called.
I saw the duplicated targets using:
var $target = $(e.currentTarget);
console.log($target);
I would add a comment to an answer, but I have low reputation.
I have the following code:
var $reviewButton = $('span.review_button');
$reviewButton
.live('click',
function(){
$('#add_reviews').show();
}
)
Later in the script, I use an AJAX call to load some content and another instance of $('span.review_button') enters the picture. I updated my code above to use '.live' because the click event was not working with the AJAX generated review button.
This code works, as the .live(click //) event works on both the static 'span.review_button' and the AJAX generated 'span.review_button'
I see however that .live is depracated so I have tried to follow the jquery documentations instructions by switching to '.on' but when I switch to the code below, I have the same problem I had before switching to '.live' in which the click function works with the original instance of 'span.review_button' but not on the AJAX generated instance:
var $reviewButton = $('span.review_button');
$reviewButton
.on('click',
function(){
$('#add_reviews').show();
}
)
Suggestions?
The correct syntax for event delegation is:
$("body").on("click", "span.review_button", function() {
$("#add_reviews").show();
});
Here instead of body you may use any static parent element of "span.review_button".
Attention! As discussed in the comments, you should use string value as a second argument of on() method in delegated events approach, but not a jQuery object.
This is because you need to use the delegation version of on().
$("#parentElement").on('click', '.child', function(){});
#parentElement must exist in the DOM at the time you bind the event.
The event will bubble up the DOM tree, and once it reaches #parentElement, it is checked for it's origin, and if it matches .child, executes the function.
So, with this in mind, it's best to bind the event to the closest parent element existing in the DOM at time of binding - for best performance.
Set your first selector (in this case, div.content) as the parent container that contains the clicked buttons as well as any DOM that will come in using AJAX. If you have to change the entire page for some reason, it can even be change to "body", but you want to try and make the selector as efficient as possible, so narrow it down to the closest parent DOM element that won't change.
Secondly, you want to apply the click action to span.review_button, so that is reflected in the code below.
// $('div.content') is the content area to watch for changes
// 'click' is the action applied to any found elements
// 'span.review_button' the element to apply the selected action 'click' to. jQuery is expecting this to be a string.
$('div.content').on('click', 'span.review_button', function(){
$('#add_reviews').show();
});
I am using jQuery v.1.7.1 where the .live() method is apparently deprecated.
The problem I am having is that when dynamically loading html into an element using:
$('#parent').load("http://...");
If I try and add a click event afterwards it does not register the event using either of these methods:
$('#parent').click(function() ...);
or
// according to documentation this should be used instead of .live()
$('#child').on('click', function() ...);
What is the correct way to achieve this functionality? It only seems to work with .live() for me, but I shouldn't be using that method. Note that #child is a dynamically loaded element.
Thanks.
If you want the click handler to work for an element that gets loaded dynamically, then you set the event handler on a parent object (that does not get loaded dynamically) and give it a selector that matches your dynamic object like this:
$('#parent').on("click", "#child", function() {});
The event handler will be attached to the #parent object and anytime a click event bubbles up to it that originated on #child, it will fire your click handler. This is called delegated event handling (the event handling is delegated to a parent object).
It's done this way because you can attach the event to the #parent object even when the #child object does not exist yet, but when it later exists and gets clicked on, the click event will bubble up to the #parent object, it will see that it originated on #child and there is an event handler for a click on #child and fire your event.
Try this:
$('#parent').on('click', '#child', function() {
// Code
});
From the $.on() documentation:
Event handlers are bound only to the currently selected elements; they
must exist on the page at the time your code makes the call to .on().
Your #child element doesn't exist when you call $.on() on it, so the event isn't bound (unlike $.live()). #parent, however, does exist, so binding the event to that is fine.
The second argument in my code above acts as a 'filter' to only trigger if the event bubbled up to #parent from #child.
$(document).on('click', '.selector', function() { /* do stuff */ });
EDIT: I'm providing a bit more information on how this works, because... words.
With this example, you are placing a listener on the entire document.
When you click on any element(s) matching .selector, the event bubbles up to the main document -- so long as there's no other listeners that call event.stopPropagation() method -- which would top the bubbling of an event to parent elements.
Instead of binding to a specific element or set of elements, you are listening for any events coming from elements that match the specified selector. This means you can create one listener, one time, that will automatically match currently existing elements as well as any dynamically added elements.
This is smart for a few reasons, including performance and memory utilization (in large scale applications)
EDIT:
Obviously, the closest parent element you can listen on is better, and you can use any element in place of document as long as the children you want to monitor events for are within that parent element... but that really does not have anything to do with the question.
The equivalent of .live() in 1.7 looks like this:
$(document).on('click', '#child', function() ...);
Basically, watch the document for click events and filter them for #child.
I know it's a little late for an answer, but I've created a polyfill for the .live() method. I've tested it in jQuery 1.11, and it seems to work pretty well. I know that we're supposed to implement the .on() method wherever possible, but in big projects, where it's not possible to convert all .live() calls to the equivalent .on() calls for whatever reason, the following might work:
if(jQuery && !jQuery.fn.live) {
jQuery.fn.live = function(evt, func) {
$('body').on(evt, this.selector, func);
}
}
Just include it after you load jQuery and before you call live().
.on() is for jQuery version 1.7 and above. If you have an older version, use this:
$("#SomeId").live("click",function(){
//do stuff;
});
I used 'live' in my project but one of my friend suggested that i should use 'on' instead of live.
And when i tried to use that i experienced a problem like you had.
On my pages i create buttons table rows and many dom stuff dynamically. but when i use on the magic disappeared.
The other solutions like use it like a child just calls your functions every time on every click.
But i find a way to make it happen again and here is the solution.
Write your code as:
function caller(){
$('.ObjectYouWntToCall').on("click", function() {...magic...});
}
Call caller(); after you create your object in the page like this.
$('<dom class="ObjectYouWntToCall">bla... bla...<dom>').appendTo("#whereeveryouwant");
caller();
By this way your function is called when it is supposed to not every click on the page.
i have 5 elements in a page.
i have selected them using class names $('.class')
i am trying to perform a function for those selected elements irrespective of event (click or hover or watever).
eg:
$('.class').hover(function(){definition1});
$('.class').click(function(){definition1});
i dont want to have 2 seperate event as above 2, instead i want the function to be executed irrespective of whether its hover or click event.
$('.class').bind('click mouseenter', function() {
// Go nuts.
});
(if using jQuery >= 1.7, swap bind() with on().)
Keep in mind that hover()'s second argument is for mouseleave event, which you haven't written anything for here.
If you want to cover most events, pass in 'blur focus focusin focusout load resize scroll unload click dblclick mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave change select submit keydown keypress keyup error' as the first argument.
You could also try to detect them with code by iterating over properties that start with on, but it sounds too flaky to me.
To bind multiple events to one element in jQuery 1.7 and later you can do the following by separating event names by spaces:
jQuery('.class').on('click hover mousenter mouseleave', function(event){
// do what you need to do
});
which you can see in jsfiddle.
But: be careful, because you can easily fire the event too much times (more than necessary and more than enough). By binding so many events some may be called unnecessarily (as in the example above the code will be fired twice when the mouse cursor will leave the element it hovered over).
If you do not want to exec a function without any event put it in
$(function(){
function test(){definition1}
});
then in html
<body onload="test();">
Assume I get a table element with ID="emTab", how do I call JS to click it?
Thanks.
document.getElementById("emTab").onclick = function() {
// your code goes here
};
See element.onclick
To trigger click event
document.getElementById("emTab").click();
See element.click
The click method is intended to be
used with INPUT elements of type
button, checkbox, radio, reset or
submit. Gecko does not implement the
click method on other elements that
might be expected to respond to
mouse–clicks such as links (A
elements), nor will it necessarily
fire the click event of other
elements.
Non–Gecko DOMs may behave differently.
When a click is used with elements
that support it (e.g. one of the INPUT
types listed above), it also fires the
element's click event which will
bubble up to elements higher up the
document tree (or event chain) and
fire their click events too. However,
bubbling of a click event will not
cause an A element to initiate
navigation as if a real mouse-click
had been received.
Cross browser way
If you can use jQuery then it would be
$("#emTab").trigger("click");
Firing events cross-browser - http://jehiah.cz/archive/firing-javascript-events-properly
its simple using JQuery
$('#emTab').click(functionToCall);
while in JS
document.getElementById('emTab').onclick = function() {};
for details on DOM events:
http://www.howtocreate.co.uk/tutorials/javascript/domevents