How can I trigger the same function from multiple events with jQuery?
Is there a way to have keyup
, keypress
, blur
, and change
events call the same function in one line or do I have to do them separately?
The problem I have is that I need to validate some data with 开发者_如何学JAVAa db lookup and would like to make sure validation is not missed in any case, whether it is typed or pasted into the box.
You can use .on()
to bind a function to multiple events:
$('#element').on('keyup keypress blur change', function(e) {
// e.type is the type of event fired
});
Or just pass the function as the parameter to normal event functions:
var myFunction = function() {
...
}
$('#element')
.keyup(myFunction)
.keypress(myFunction)
.blur(myFunction)
.change(myFunction)
As of jQuery 1.7, the .on()
method is the preferred method for attaching event handlers to a document. For earlier versions, the .bind()
method is used for attaching an event handler directly to elements.
$(document).on('mouseover mouseout',".brand", function () {
$(".star").toggleClass("hovered");
})
I was looking for a way to get the event type when jQuery listens for several events at once, and Google put me here.
So, for those interested, event.type
is my answer :
$('#element').on('keyup keypress blur change', function(event) {
alert(event.type); // keyup OR keypress OR blur OR change
});
More info in the jQuery doc.
You can use bind method to attach function to several events. Just pass the event names and the handler function as in this code:
$('#foo').bind('mouseenter mouseleave', function() {
$(this).toggleClass('entered');
});
Another option is to use chaining support of jquery api.
Is there a way to have
keyup
,keypress
,blur
, andchange
events call the same function in one line?
It's possible using .on()
, which accepts the following structure: .on( events [, selector ] [, data ], handler )
, so you can pass multiple events to this method. In your case it should look like this:
$('#target').on('keyup keypress blur change', function(e) {
// "e" is an event, you can detect the type of event using "e.type"
});
And here is the live example:
$('#target').on('keyup keypress blur change', function(e) {
console.log(`"${e.type.toUpperCase()}" event happened`)
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="target">
If you attach the same event handler to several events, you often run into the issue of more than one of them firing at once (e.g. user presses tab after editing; keydown, change, and blur might all fire).
It sounds like what you actually want is something like this:
$('#ValidatedInput').keydown(function(evt) {
// If enter is pressed
if (evt.keyCode === 13) {
evt.preventDefault();
// If changes have been made to the input's value,
// blur() will result in a change event being fired.
this.blur();
}
});
$('#ValidatedInput').change(function(evt) {
var valueToValidate = this.value;
// Your validation callback/logic here.
});
This is how i do it.
$("input[name='title']").on({
"change keyup": function(e) {
var slug = $(this).val().split(" ").join("-").toLowerCase();
$("input[name='slug']").val(slug);
},
});
You could define the function that you would like to reuse as below:
var foo = function() {...}
And later you can set however many event listeners you want on your object to trigger that function using on('event') leaving a space in between as shown below:
$('#selector').on('keyup keypress blur change paste cut', foo);
The answer by Tatu is how I would intuitively do it, but I have experienced some problems in Internet Explorer with this way of nesting/binding the events, even though it is done through the .on()
method.
I havn't been able to pinpoint exactly which versions of jQuery this is the problem with. But I sometimes see the problem in the following versions:
- 2.0.2
- 1.10.1
- 1.6.4
- Mobile 1.3.0b1
- Mobile 1.4.2
- Mobile 1.2.0
My workaround have been to first define the function,
function myFunction() {
...
}
and then handle the events individually
// Call individually due to IE not handling binds properly
$(window).on("scroll", myFunction);
$(window).on("resize", myFunction);
This is not the prettiest solution, but it works for me, and I thought I would put it out there to help others that might stumble upon this issue
$("element").on("event1 event2 event..n", function() {
//execution
});
This tutorial is about handling multiple events.
It's simple to implement this with the built-in DOM methods without a big library like jQuery, if you want, it just takes a bit more code - iterate over an array of event names, and add a listener for each:
function validate(event) {
// ...
}
const element = document.querySelector('#element');
['keyup', 'keypress', 'blur', 'change'].forEach((eventName) => {
element.addEventListener(eventName, validate);
});
If you'd want to mimic adding to more than 1 element:
const elements = document.querySelectorAll('.commonSelector');
['keyup', 'keypress', 'blur', 'change'].forEach((eventName) => {
elements.forEach(element => {
element.addEventListener(eventName, validate);
});
});
Instead of:
$('#element').on('keyup keypress blur change', function(e) {
// e.type is the type of event fired
});
You can use:
$('#element').on('input', function(e) {
// e.type is the type of event fired
});
input
is trigerred for keyup
keypress
blur
change
events even for paste
!
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