Run jQuery event handler only once - javascript

I try to use a jquery event only once, and I have the following function:
function usrPlay() {
var flag = true;
while (flag === true) {
$(".pincha").click(function() {
console.log($(this).attr("value"));
flag = false;
});
}
}
But...it seems that that makes an infinite loop, but I can`t see why.
Any help? Thank you!!

jQuery has a function named by .one() for this.
You can use the code below for your problem.
$(".pincha").one( "click", function(){
console.log($(this).attr("value"));
});
For further information about .one()
http://api.jquery.com/one/

But...it seems that that makes an infinite loop, but I can`t see why.
This is because you only attach event inside the loop, event handler is not executed inside loop so flag will not change to false. And you will probably need global flag var instead of local var because event handler will not be executed in scope of usrPlayfunction. Try this:
function usrPlay(){
window.flag = true;
$(".pincha").click(function(){
if (window.flag === true){
console.log($(this).attr("value"));
window.flag = false;
}
});
}

Related

Choose only the first button

I'm trying to do that only one can happen, if you click yes or no. As it is now if you click "no" in the first time and "yes" in the second time, it will execute it twice .
function confirm() {
$("#no").one("click", function(){
return false;
});
}
$("#yes").one("click", function () {
//do something
});
thanks for help
Both events are attached at document.ready I assume, which means they will remain active indefinitely unless you specify otherwise.
The following approach is fairly basic, just set a variable 'hasClicked' to false. And as soon as either one of them is clicked, set 'hasClicked' to true. Each button has an if-structure that only executes the code IF 'hasClicked' is false.
Try the following:
var hasClicked = false;
function confirm(){
$("#no").one("click", function(){
if (!hasClicked){
hasClicked = true;
return false;
}
});
$("#yes").one("click", function () {
if (!hasClicked) {
hasClicked = true;
//do something
}
});
}
As you can't unbind an event binded with one() check this answer
So you'll have to work around like this:
function confirm() {
$("#no").bind("click", function(){
$(this).unbind(); // prevent other click events
$("#yes").unbind("click"); // prevent yes click event
// Do your stuff
});
}
$("#yes").bind("click", function () {
$(this).unbind();
$("#no").unbind("click");
// Do your stuff
});
Assign your buttons a class called confirmation. Set a event handler based on class. Read the value of the button to decide what you want to do.
$(".confirmation").one("click", function(){
if($(this).val() === 'yes'){
//do something
}else{
return false;
}
}

javascript / jquery - avoid repeating evaluation of a conditional

I currently have a conditional running in jquery's scroll event, which doesn't seem to make a lot of sense since it will only execute once. I was wondering if there is any way to ensure that the conditional will only be evaluated once.
here's my code:
$window.scroll(function() {
if (s1_doAnimate == true){
s1_doAnimate = false;
}
})
Use $.one
$(window).one('scroll', function(){
...
});
You can unbind the handler once the condition has been met;
$window.scroll(function foo /* give the function a name */ () {
if (s1_doAnimate == true){
s1_doAnimate = false;
// Unbind the handler referenced by the name...
$window.off(foo);
}
})

jQuery unbind click event function and re-attach depending on situation

The code below I use to create a sliding menu. I need to know how to unbind the function attached to the click event and re-attach it some other time. (using jQuery 1.7.2)
$(document).ready(function(){
$('.section').hide();
$('.header').click(function(){
if($(this).next('.section').is(':visible'))
{
$('.section:visible').slideUp()
$('.arrows:visible').attr("src","right.gif")
}
else
{
$('.section').slideUp();
$(this).next('.section').slideToggle();
$(this).find('.arrows').attr("src","down.gif")
});
});
The code below is what I have so far
$('#printVers').click(function(){
if($('#formVersion').val() != "Print")
{
$('.header').unbind('click');
}
else
{
//else re-attach functionality?
}
});
Thanks
Simply make a named function. You can go low tech here and back to basics to unbind and reattach specific events.
function doStuff()
{
if($(this).,next('.section').is(':visible'))
...
}
$('.header').on('click', doStuff);
$('.header').off('click', doStuff);
Instead of unbind and re-bind, I suggest you to add a simple class to .header and check for the class in the click handler. See below,
$('#printVers').click(function(){
if($('#formVersion').val() != "Print")
{
$('.header').addClass('dontClick');
} else {
$('.header').removeClass('dontClick');
}
});
And in your .header click handler,
$('.header').click(function(){
if ($(this).hasClass('dontClick')) {
return false;
}
//rest of your code
If you insist on having a unbind and bind, then you can move the handler to a function and unbind/bind the function any number of time..
You can try something like this.
$('#printVers').click(function(){
if($('#formVersion').val() != "Print")
{
$('.header').addClass('clickDisabled');
}
else
{
$('.header').removeClass('clickDisabled');
}
});
And then in the click handler check for this class.
$(document).ready(function(){
$('.section').hide();
$('.header').click(function(){
if(!$(this).hasClass('clickDisabled')){
...
...
}
});
});
Why not make that top section a function, and then call it in your else statement?
You could try setting a variable as a flag. var canClick = ($('#formVersion').val() != 'Print'); Then in the click handler for your .header elements check to see if canClick is true before executing your code.
If you still want to remove the handler you can assign the events object to a variable. var eventObj = #('.header').data('events'); That will give you an object with all the handlers assigned to that object. To reassign the click event it would be like $('.header').bind('click', eventObj.click[0]);
After trying so hard with bind, unbind, on, off, click, attr, removeAttr, prop I made it work.
So, I have the following scenario: In my html i have NOT attached any inline onclick handlers.
Then in my Javascript i used the following to add an inline onclick handler:
$(element).attr('onclick','myFunction()');
To remove this at a later point from Javascript I used the following:
$(element).prop('onclick',null);
This is the way it worked for me to bind and unbind click events dinamically in Javascript. Remember NOT to insert any inline onclick handler in your elements.
You could put all the code under the .click in a separated function
function headerClick(){
if($(this).next('.section').is(':visible'))
{
$('.section:visible').slideUp()
$('.arrows:visible').attr("src","right.gif")
}
else
{
$('.section').slideUp();
$(this).next('.section').slideToggle();
$(this).find('.arrows').attr("src","down.gif")
}
}
and then bind it like this:
$(document).ready(function(){
$('.section').hide();
$('.header').click(headerClick);
});
$('#printVers').click(function(){
if($('#formVersion').val() != "Print")
{
$('.header').unbind('click');
}
else
{
$('.header').click(headerClick);
}
});

How to apply multiple events to the same function

I'm not the best at this jquery stuff. But I'm trying to seperate the action from the function so I can apply multiple events that cause the same function. Unfortunately this isn't working. Anyone know why?
Updated Function, but still errors
$(document).ready(function() {
var $info_items = jQuery('.checkbox.has_info, .has_info');
$info_items.click(function(event) {
$(this).show_text(event);
});
// I suspect it has something to do with this initalizer of the function here
jQuery.fn.show_text = function(event){
var $info_item = jQuery(this);
$info_items.filter(function(index){
return $(".hidden_text").css("display","block");
}).not($info_item).parent().next().next().hide("slow");
$info_item.parent().next().next().show("fast");
});
});
What is e, the event? You need to name the event argument to the click() function to use it. Also, to invoke show_text such that it has a this, you need to invoke it on an element:
$info_items.click(function (event) {
// 'this' is the element in $info_items which was clicked
// invoke show_text on the element in question
$(this).show_text(event);
});
You also have an extra ) on your final }); line.
You can use jQuery bind to attach several events to a single function.
$('#whatever').bind('mouseover focus click', function() {
your_custom_function();
});
Are you looking for something like this?
var handle = function(event) {
$(event.currentTarget).show_text(event);
};
$info_items.bind('click blur', handle);

Turn function on and off

I have a jQuery tip function. I would like to create a button to turn on and turn off the function. I want it to be on by default.
Is it possible to create a link to turn on and off a function?
You can dynamically add and subtract event handlers with the bind and unbind functions.
$("#id").click( function() {
if ( HANDLER_IS_SET )
$("#button").unbind( "click");
else
$("#button").bind( "click", myEventHandlerFunction );
}
You can set a boolean to check if it's on or off, or bind and unbind a function.
var isOn = false;
$("#button").click(function(){ isOn = !isOn; });
$("#executebutton").click(MyFunction);
function MyFunction()
{
if (!isOn) return;
// do stuff
}
or
$("#button").click
(
function()
{
if ($("#executebutton").data("events").click != undefined)
$("#executebutton").unbind("click");
else
$("#executebutton").bind("click", MyFunction);
}
);
A little more info is needed, but you could use a global variable to toggle an if statement within the function so it doesn't execute anything, but the function will still be called.

Categories

Resources