Callbacks running twice after AJAX content loaded - javascript

I have a page loading content with the waypoints infinite scroller plugin.
On the success of the AJAX call and after DOM elements are added, a callback runs to re-initilize javascript functionality, like carousels, buttons and other animation.
On the first AJAX call, buttons tasked with toggling work properly. On the next AJAX call, the new DOM items work, but the previous buttons now execute toggles twice when clicked. On the third call, original items now run three times, the second items twice and the new ones once, so on and so fourth, continuing to compound as AJAX content is called.
How can I isolate the callback to not affect the previously loaded content, or, is there a way to set a global state for the JS, so that I don't need the callback each time?
Some pseudo code:
$('.infinite-container').waypoint('infinite', {
onAfterPageLoad: function() {
//Carousel options
$('.carousel-container').carousel({
options: here,
....
});
//Button Toggles
$('.button').click(function(){
var self = $(this);
$(this).siblings('.caption').animate({
height: 'toggle'
}, 200, function() {
// Callback after animate() completes.
if(self.text() == 'Hide Details'){
self.text('Show Details');
} else {
self.text('Hide Details');
}
});
});
}
});
Edit: Thanks everybody. All the answers lead me to differing but appropriate solutions. The selected was picked as it's a great collection of all the suggested issues and worth the read.

Check out this answer. I think it is the same situation you are having and has a solution:
Best way to remove an event handler in jQuery?

You are attaching a new click handler each time that block of code gets executed. The result is multiple click handlers being bound to your button. Use jQuery's unbind: http://api.jquery.com/unbind/ to remove any click handler(s) before adding a new one:
$('.infinite-container').waypoint('infinite', {
onAfterPageLoad: function() {
//Carousel options
$('.carousel-container').carousel({
options: here,
....
});
// Un-bind click handler(s)
$('.button').unbind('click');
//Button Toggles
$('.button').click(function(){
var self = $(this);
$(this).siblings('.caption').animate({
height: 'toggle'
}, 200, function() {
// Callback after animate() completes.
if(self.text() == 'Hide Details'){
self.text('Show Details');
} else {
self.text('Hide Details');
}
});
});
}
});

Try bind only once click event to button. Of course you can use on instead of live.
$('.button').live('click', function(){
var self = $(this);
$(this).siblings('.caption').animate({
height: 'toggle'
}, 200, function() {
// Callback after animate() completes.
if(self.text() == 'Hide Details'){
self.text('Show Details');
} else {
self.text('Hide Details');
}
});
});
$('.infinite-container').waypoint('infinite', {
onAfterPageLoad: function() {
//Carousel options
$('.carousel-container').carousel({
options: here,
....
});
//Button Toggles
}
});

$('.button').click(function(){
You add an event handler to every button that has the class button. When the second button is added then you add it to every ... which means button 1 and button 2. And so on.
Try
$('.button').last().click(function(){

Related

Prevent duplcate ajaxLoad event calls added with a click event

I am using MVC Razor - The overall goal is to create a "print view" pop-up page.
The print view button is on the parent page, when clicked, an ajax event is fired which will populate an empty div with the contents that are to be included in the print preview:
//from the view
#Ajax.ActionLink("prntPreview", "Display", new { ID = Model.Detail.ID }, new AjaxOptions { UpdateTargetId = "modal" }, new { #class = "btnPreview" })
then, using JavasScript/jQuery I clone the contents of that newly populated div and create a new window with the contents:
//in the scripts file
$('.btnPreview').on('click', function () {
$(document).ajaxStop(function () {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
}, 300);
});
});
function PopupPrint(data) {
var mywindow = window.open('', '', 'height=500,width=800,resizable,scrollbars');
mywindow.document.write(data);
mywindow.focus();
//do some other stuff here
}
This is where I run into difficulty. The first time I click, everything is working as expected - however, if you do not navigate away from the parent page and try to use the print preview button a second time, the popup will be created twice, then three times etc. with each additional click.
I think that the problem is because each time the .btnPreview is clicked, a new $(document).ajaxStop event is being created, causing the event to fire multiple times.
I have tried to create the ajaxStop as a named function which is declared outside the scope of the click event and then clear it but this produces the same result:
var evnt = "";
$('.btnPreview').on('click', function () {
evnt =
$(document).ajaxStop(function () {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
evnt = "";
}, 300);
});
});
I also have other ajaxStop events initialised so don't want to completely unbind the ajaxStop event. Is it possible to get the name or something from each ajax event so that I can clear just that event or similar?
You can prevent adding additional triggers by checking with a variable outside of scope like this:
(function() {
var alreadyAdded = false;
$('.btnPreview').on('click', function() {
if (!alreadyAdded) {
$('.eventTrigger').click(function() {
console.log('printing!');
});
alreadyAdded = true;
}
});
})();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button class="btnPreview">Add Event</button>
<button class="eventTrigger">Trigger</button>
Please note that the variable and function are encapsulated in a self-executing anonymous function and do not pollute global space.
The output of the sample can be seen in the developer console. If you remove the if-check then every click on the "Add Event" button produces an additional print statement on the "Trigger" button each time it is clicked (which is your problem). With the if, there will ever only be one event on the trigger button.
There were 2 issues which I needed to address.
The answer is to unbind the ajax event after it has checked that the request had completed and to unbind and reattach the button click trigger.
This is how I did it:
//in the scripts file
$('.btnPreview').off('click').on('click', function () {
$(document).ajaxComplete(function (e) {
var pageData = $('#modal').html();
setTimeout( //add a slight delay
function () {
PopupPrint(pageData);
}, 300);
$(this).off(e);
});
});
I unbound the click event by adding .off('click') before the .on. this is what stopped it popping up multiple times.
The other issue was that anytime any ajax event completed (triggered by something else) that would also create the popup - to get around that, I added $(this).unbind(e); to the end of the code block which removed the ajaxComplete binding which was being triggered each time any ajax event completed.

stop and later persue javascript event in jquery ui modal dialog

I want to stop an event show a modal dialog and if the user presses yes persue this event. event.run() brings an error in firefox.
jQuery(element).click(function(event) {
event.preventDefault();
dialog.dialog({
buttons: {
'Ja': function() {
event.run();
},
'Nein': function() {
jQuery(this).dialog('close');
}
}
}).dialog('open');
});
Thanks to a friend and hashbrown I managed to solve this problem. An event cannot be paused and persued. If it is paused it will block the whole DOM. Try:
jQuery(link).click(function(){while(true)});
When using jQuery its possible to set additional event parameters what I did:
jQuery(element).click(function(event, show_dialog) {
var that = jQuery(this);
if(!show_dialog) {
dialog.dialog({
buttons: {
'Yes': function() {
that.trigger(event.type, [true]);
},
'No': function() {
jQuery(this).dialog('close');
}
}
}).dialog('open');
return false;
} else {
dialog.dialog('close');
return true;
}
});
First click show_dialog is undefined and modal dialog is shown. Clicking on Yes in modal dialog triggers the event.type (click) with the additional parameter true for show_dialog. http://api.jquery.com/trigger/#trigger-eventType-extraParameters
It was not possible to that.trigger(event, [true]);. I think cause events default action was prevented before.
That is because immediately after creating the popup the function returns and the event expires.
What you'll have to do is .trigger() a new event.
Note: set some sort of global variable to ignore this second event firing in your anonymous function (infinite loop problem).
Can I ask why you want to do this; what would click go off and do if you let it?
If it just fires off a different function, why not just call that function instead of attempting event.run()?

Redefining a jQuery dialog button

In our application we use a general function to create jQuery dialogs which contain module-specific content. The custom dialog consists of 3 buttons (Cancel, Save, Apply). Apply does the same as Save but also closes the dialog.
Many modules are still using a custom post instead of an ajax-post. For this reason I'm looking to overwrite/redefine the buttons which are on a specific dialog.
So far I've got the buttons, but I'm unable to do something with them. Is it possible to get the buttons from a dialog (yes, I know) but apply a different function to them?
My code so far:
function OverrideDialogButtonCallbacks(sDialogInstance) {
oButtons = $( '#dialog' ).dialog( 'option', 'buttons' );
console.log(oButtons); // logs the buttons correctly
if(sDialogInstance == 'TestInstance') {
oButtons.Save = function() {
alert('A new callback has been assigned.');
// code for ajax-post will come here.
}
}
}
$('#dialog').dialog({
'buttons' : {
'Save' : {
id:"btn-save", // provide the id, if you want to apply a callback based on id selector
click: function() {
//
},
},
}
});
Did you try this? to override button's callback based on the need.
No need to re-assign at all. Try this.
function OverrideDialogButtonCallbacks(dialogSelector) {
var button = $(dialogSelector + " ~ .ui-dialog-buttonpane")
.find("button:contains('Save')");
button.unbind("click").on("click", function() {
alert("save overriden!");
});
}
Call it like OverrideDialogButtonCallbacks("#dialog");
Working fiddle: http://jsfiddle.net/codovations/yzfVT/
You can get the buttons using $(..).dialog('option', 'buttons'). This returns an array of objects that you can then rewire by searching through them and adjusting the click event:
// Rewire the callback for the first button
var buttons = $('#dialog').dialog('option', 'buttons');
buttons[0].click = function() { alert('Click rewired!'); };
See this fiddle for an example: http://jsfiddle.net/z4TTH/2/
If necessary, you can check the text of the button using button[i].text.
UPDATE:
The buttons option can be one of two forms, one is an array as described above, the other is an object where each property is the name of the button. To rewire the click event in this instance it's necessary to update the buttons option in the dialog:
// Rewire the callback for the OK button
var buttons = $('#dialog').dialog('option', 'buttons');
buttons.Ok = function() { alert('Click rewired!'); };
$('#dialog').dialog('option', 'buttons', buttons);
See this fiddle: http://jsfiddle.net/z4TTH/3/
Can you try binding your new function code with Click event of Save?
if(sDialogInstance == 'TestInstance') {
$('#'+savebtn_id).click(function() {
alert('A new callback has been assigned.');
// code for ajax-post will come here.
});
}

Rebinding Scroll Action After Ajax Call Interrupted by prettyLoader

I have written your basic jQuery infinite scroll function. Expected behavior is consistent with the infinite scroll design pattern.
Upon completion of the ajax server call, I am rebinding the scroll event.
Everything works as expected for the first ajax call, however the scroll event is not being rebound for some reason. Adding in console data to debug the function shows that the code is executed through the end of setScrollingAction(), yet the scroll event does not take.
What am I missing?
// Function to make the ajax call, append the results and rebind the scroll event
function loadContent(opts) {
$(opts.scrollTarget).unbind('scroll');
$(opts.loaderObject).show();
$.get($(opts.gridObject).attr('data-link'), function(data) {
var $data = $(data);
$(opts.gridObject).append($data.find(opts.appendObject));
$(opts.loaderObject).hide();
$(opts.gridObject).attr('data-link', $data.find(opts.gridObject).attr('data-link'));
setScrollingAction(opts);
});
};
// Function to set the loading action to the scroll event
function setScrollingAction(opts) {
$(opts.scrollTarget).bind("scroll", function(event) {
if (inLoadingRange(opts)) { loadContent(opts); }
});
};
// Function to determine height from bottom of page
function inLoadingRange(opts) {
var target = opts.scrollTarget;
return ($(target).scrollTop()+opts.heightOffset >= $(document).height() - $(target).height());
};
// Fire it up
$(document).ready(function(){
opts = {
'scrollTarget': $(window),
'loaderObject': "#loading",
'gridObject' : '#tileGrid',
'appendObject': '.newItem',
'heightOffset': 10
};
setScrollingAction(opts);
});
Turns out it was a conflict with the prettyLoader plugin.
If you look through prettyLoader.js you will find the following function:
$.prettyLoader.hide = function() {
$(document).unbind('click', $.prettyLoader.positionLoader);
$(document).unbind('mousemove', $.prettyLoader.positionLoader);
$(window).unbind('scroll');
$('.prettyLoader').fadeOut(settings.animation_speed, function() { $(this).remove(); });
};
All scroll event assignments are being unbound on the third line of the function. Commenting out this line solved the problem, and did not have a noticeable effect of the loading image.
$.prettyLoader.hide = function() {
$(document).unbind('click', $.prettyLoader.positionLoader);
$(document).unbind('mousemove', $.prettyLoader.positionLoader);
//$(window).unbind('scroll');
$('.prettyLoader').fadeOut(settings.animation_speed, function() { $(this).remove(); });
};

Suspend Default Event in jQuery

I am trying to delay the default event or events in a jQuery script. The context is that I want to display a message to users when they perform certain actions (click primarily) for a few seconds before the default action fires.
Pseudo-code:
- User clicks link/button/element
- User gets a popup message stating 'You are leaving site'
- Message remains on screen for X milliseconds
- Default action (can be other than href link too) fires
So far, my attempts look like this:
$(document).ready(function() {
var orgE = $("a").click();
$("a").click(function(event) {
var orgEvent = event;
event.preventDefault();
// Do stuff
doStuff(this);
setTimeout(function() {
// Hide message
hideMessage();
$(this).trigger(orgEvent);
}, 1000);
});
});
Of course, this doesn't work as expected, but may show what I'm trying to do.
I am unable to use plugins as ths is a hosted environment with no online access.
Any ideas?
I would probably do something like this.
$("a").click(function(event) {
event.preventDefault();
doStuff(this);
var url = $(this).attr("href");
setTimeout(function() {
hideMessage();
window.location = url;
}, 1000);
});
I'm not sure if url can be seen from inside the timed function. If not, you may need to declare it outside the click handler.
Edit: If you need to trigger the event from the timed function, you could use something similar to what karim79 suggested, although I'd make a few changes.
$(document).ready(function() {
var slept = false;
$("a").click(function(event) {
if(!slept) {
event.preventDefault();
doStuff(this);
var $element = $(this);
// allows us to access this object from inside the function
setTimeout(function() {
hideMessage();
slept = true;
$element.click(); //triggers the click event with slept = true
}, 1000);
// if we triggered the click event here, it would loop through
// this function recursively until slept was false. we don't want that.
} else {
slept = false; //re-initialize
}
});
});
Edit: After some testing and research, I'm not sure that it's actually possible to trigger the original click event of an <a> element. It appears to be possible for any element other than <a>.
Something like this should do the trick. Add a new class (presumably with a more sensible name than the one I've chosen) to all the links you want to be affected. Remove that class when you've shown your popup, so when you call .click() again your code will no longer run, and the default behavior will occur.
$("a").addClass("fancy-schmancy-popup-thing-not-yet-shown").click(function() {
if ($(this).hasClass("fancy-schmancy-popup-thing-not-yet-shown"))
return true;
doStuff();
$(this).removeClass("fancy-schmancy-popup-thing-not-yet-shown");
var link = this;
setTimeout(function() {
hideMessage();
$(link).click().addClass("fancy-schmancy-popup-thing-not-yet-shown";
}, 1000);
return false;
});
Probably the best way to do this is to use unbind. Something like:
$(document).ready(function() {
$("a").click(function(event) {
event.preventDefault();
// Do stuff
this.unbind(event).click();
});
})
This might work:
$(document).ready(function() {
$("a").click(function(event) {
event.preventDefault();
doStuff(this);
setTimeout(function() {
hideMessage();
$(this).click();
}, 1000);
});
});
Note: totally untested

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