How to prevent calling of en event handler twice on fast clicks?
There is a button and when user clicks on button, some data is saved to back-end. Issue is when user clicks on button very quickly, event handler is getting executed multiple times.
This is the code
var x = 1;
$('#button').click(function() {
// Do something
// Save some data on network
x++;
console.log(x);
});
I want this handler to get executed when user clicks on button just once. Even In case of double or tripple click, this should get executed only once. I just want to avoid quick clicks, this handler can get executed again ofcourse
I have multiple solutions in my mind like
-
Define a global variable like
IS_BUTTON_HANDLER_WORKING = falseand when you enter the handler set it to true and in the end set it to false again. And check if it is true just return from the function. -
Detach the handler in the beginning and reattach in the end.
Consider you have 25 buttons in your application. What should be the best approach to implement this.
Take a look at this Fiddle
Solution
$('#button').click(function() {
$(this).attr('disabled', true);
// Do something
// Save some data on network
$(this).removeAttr('disabled');
});
Using this, we are sure that our next handler will get executed only when previous execution has been done completely.
David Walsh has a great solution.
// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
function debounce(func, wait, immediate) {
var timeout;
return function() {
var context = this, args = arguments;
var later = function() {
timeout = null;
if (!immediate) func.apply(context, args);
};
var callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) func.apply(context, args);
};
};
There are multiple ways of dealing with this:
You can disable/hide the button after the click:
$('#button').attr("disabled", true);
You can also set a timeout on each click to ensure it does not execute again:
var x, y = 1;
$('#button').click(function() {
if (x) clearTimeout(x);
x = setTimeout(function() {
// do the work here
y++;
console.log(y);
// ----------------
}, 1000);
});
So each time the button is clicked, it will only actually execute the code after a 1000 milliseconds, if the button is clicked in rapid succession, the timeout will just be cleared and start over again.
note that the above is untested
Personally I think the disabled solution is the best as it indicates to the user that he has clicked and something is happening, you can even show a loader next to the button as well.
As per edit
You should use .one()
or
You can unbind event on click function
var x = 1;
function myButtonClick() {
$('#button').unbind('click');
// Do something
// Save some data on network
x++;
console.log(x);
$('#button').bind('click', myButtonClick);
}
$('#button').bind('click', myButtonClick);
You can make use of jQuery one() method as shown here
I’m using the simple solution below and its been working for me well :
var x = 1;
e.handled=false;
$('#button').click(function(e) {
if(e.handled==false){
e.handled=true;
// Do something
// Save some data on network
x++;
console.log(x);
}
});
You are looking for this
$( "button" ).one( "click", function(evt) {
x++;
console.log(x);
});
Or if u need a certain time interval to lapse between two effective clicks.
var last, diff;
$( "button" ).click(function( event ) {
if (last){
diff = event.timeStamp - last;
if (diff >= SOMEVAL){
x++;
console.log(x);
}
}
last = event.timeStamp;
});
var btn = document.querySelector('#twofuns');
btn.addEventListener('click',method1);
btn.addEventListener('click',method2);
function method2(){
console.log("Method 2");
}
setTimeout(function(){
btn.removeEventListener('click',method1);
},5000);
function method1(){
console.log("Method 1");
}<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Pramod Kharade-RemoveEventListener after Interval</title>
</head>
<body>
<button id="twofuns">Click Me!</button>
</body>
</html>You can remove one listener among multiple in java-script like above.
Assuming you have attached an event listener to the button, one approach is to just remove the event listener from the button and attach it afterwards again if needed. To do so, add the following code in the event listener function itself:
function handleButtonClick(e) {
e.target.removeEventListener("click", handleBackButton);
}
Depending on your setup this could work.
Try the following code
var x = 1;
var fewSeconds=10; /*10 seconds*/
$('#button').click(function() {
$('#button').attr("disabled", "disabled");
x++;
console.log(x);
var btn = $(this);
btn.prop('disabled', true);
setTimeout(function(){
btn.prop('disabled', false);
}, fewSeconds*1000);
});
start the Busy Indicator on button click and stop it before return at the end
Function DoSomething(){
startBusyIndicator();
// perform Action //
stopBusyIndicator();
return;
}
