I create dropdown dynamically.
Their ids are ddl1, ddl2, ddl3 and so on.
$('#ddl1').focus(function() {
var previous = this.value;
}).change(function() {
var index = $(this).find('selected').index();
$('#ddl1').find('option:eq(' + index + ')').hide();
$('#ddl2').find('option:eq(' + index + ')').hide();
});
$('#ddl2').focus(function() {
...
Creation of 7 dropdowns makes me to write 7 change event handlers.
How to implement dynamically create change event?
My dropdown append methods are:
var x=1;
var dropdown=('#ddl1').html();
$('#btnadd').click(function() {
$('#divname').append('<select id="ddl'+x+' > </select> <option>../option>');
x++;
});
Give a common class to every dropdown and refer to that. Also, use .on() (event delegation) to catch dynamic created elements:
$(document).on('change', '.common-class', function() {
//Your function
var currentId = $(this).attr('id');
});
UPDATE
Add the same class every time you append a select element:
//...
$('#divname').append('<select id="ddl'+ x + '" class="common-class"><option>../option></select>');
SELECTED OPTION
In order to get the selected option:
$('#current-id').find('option:selected').index();
Variant without delegated events to reduce resource usage:
var $dds = $('select');
$dds.each(function(index) {
var $this = $(this);
processDdChange($this);
});
function processDdChange($obj) {
$obj.on('change', function(e) {
var $this = $(this);
alert($this.attr('id') + ' | ' + $this.find(':selected').val());
});
}
https://jsfiddle.net/tasmanangel/2p9mbs7h/
I have information that comes out of a database and gets put into a list with a checkbox by each element. This is how it is currently done:
function subjects(){
$.ajax({
url: "lib/search/search.subject.php",
async: "false",
success: function(response){
alert(response);
var responseArray = response.split(',');
for(var x=0;x<responseArray.length;x++){
$("#subjects").append("<br />");
$("#subjects").append(responseArray[x]);
$("#subjects").append("<input type='checkbox' />");
}
}
});
}
it works fine, but I need a way to pick up on if a checkbox is clicked, and if it is clicked then display which one was clicked, or if multiple ones are clicked.
I can't seem to find a way to pick up on the checkboxs at all.
the response variable is "math,science,technology,engineering"
Because you are populating the Checkboxes Dynamically you need to Delegate the event
$("#subjects").on("click", "input[type='checkbox']", function() {
if( $(this).is(":checked") ) {
alert('Checkbox checked')
}
});
To better capture the data it is better if you encase the corresponding data into a span , so that it can be easier to search..
$("#subjects").append('<span>'+responseArray[x] + '</span>');
$("#subjects").on("click", "input[type='checkbox']", function() {
var $this = $(this);
if( $this.is(":checked") ) {
var data = $this.prev('span').html();
alert('Current checkbox is : '+ data )
}
});
It would be best to give your dynamically injected checkboxes a class to target them better, but based on your code try:
$("#subjects").on("click", "input", function() {
if( $(this).is(":checked") ) {
// do something
}
});
Since your input elements are added dynamically, you need to use jQuery's .on() function to bind the click event to them. In your case you need to use .on() to bind to an element that exist in the DOM when the script is loaded. In your case, the element with the ID #subjects.
This note from the docs is mainly for machineghost who downvoted my answer for no apparent reason:
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().
To ensure the elements are present and can be selected, perform event
binding inside a document ready handler for elements that are in the
HTML markup on the page. If new HTML is being injected into the page,
select the elements and attach event handlers after the new HTML is
placed into the page.
$('#subjects input[type=checkbox]').on('click',function(){
alert($(this).prop('checked'));
});
or the change event: in case someone uses a keyboard
$('#subjects input[type=checkbox]').on('change',function(){
alert($(this).prop('checked'));
});
simple fiddle example:http://jsfiddle.net/Dr8k8/
to get the array example use the index of the inputs
alert($(this).prop('checked') +'is'+ $(this).parent().find('input[type=checkbox]').index(this)+ responseArray[$(this).parent().find('input[type=checkbox]').index(this) ]);
simplified example: http://jsfiddle.net/Dr8k8/1/
EDIT: Just for an example, you could put the results in an array of all checked boxes and do somthing with that:
$('#subjects>input[type=checkbox]').on('change', function() {
var checklist = [];
$(this).parent().find('input[type=checkbox]').each(function() {
$(this).css('background-color', "lime");
var myindex = $(this).parent().find('input[type=checkbox]').index(this);
if ($(this).prop('checked') == true) {
checklist[myindex] = responseArray[myindex];
}
});
$('#currentlyChecked').text(checklist);
});
EDIT2:
I thought about this a bit and you can improve it by using .data() and query that or store it based on an event (my button called out by its id of "whatschecked")
var responseArray = ['math', 'science', 'technology', 'engineering'];// just for an example
var myList = '#subjects>input[type=checkbox]';//to reuse
for (var x = 0; x < responseArray.length; x++) {
// here we insert it all so we do not hit the DOM so many times
var iam = "<br />" + responseArray[x] + "<input type='checkbox' />";
$("#subjects").append(iam);
$(myList).last().data('subject', responseArray[x]);// add the data
}
var checklist = [];// holds most recent list set by change event
$(myList).on('change', function() {
checklist = [];
$(myList).each(function() {
var myindex = $(this).parent().find('input[type=checkbox]').index(this);
if ($(this).prop('checked') == true) {
checklist.push($(this).data('subject'));
alert('This one is checked:' + $(this).data('subject'));
}
});
});
// query the list we stored, but could query the checked list data() as well, see the .each() in the event handler for that example
$("#whatschecked").click(function() {
var numberChecked = checklist.length;
var x = 0;
for (x = 0; x < numberChecked; x++) {
alert("Number " + x + " is " + checklist[x] + " of " + numberChecked);
}
});
live example of last one: http://jsfiddle.net/Dr8k8/5/
The general pattern to do something when a checkbox input is clicked is:
$('input[type=checkbox]').click(function() {
// Do something
})
The general pattern to check whether a checkbox input is checked or not is:
var isItChecked = $('input[type=checkbox]').is(':checked');
In your particular case you'd probably want to do something like:
$('#subjects input[type=checkbox]').click(function() {
to limit the checkboxes involved to the ones inside your #subjects element.
I am trying to implement a script to set different class name on a specific element…
Let's suppose the dom looks like this:
<body class='pre-existing-class-name'>
If I make
smartToogle('body', 'new-class');
// the dom should look like this
// <body class='pre-existing-class-name new-class'>
smartToogle('body', 'new-class-2');
// the dom should look like this
// <body class='pre-existing-class-name new-class-2'>
I did the following code but it does not work:
var smartToogle = function (element, newClassName) {
var oldClassName;
var $element = $(element);
$element.addClass(newClassName);
if (oldClassName !== newClassName) {
$element.removeClass(oldClassName);
}
oldClassName = newClassName;
};
Requirements:
1) I am using query
2) I would like to pass just one class name, the new one.
Solution:
The following code works but I do not like it because it uses global variable.
Any hint to fix it?
function myToggle(newClassName) {
if (window.oldClassName) {
$('body').toggleClass(window.oldClassName);
}
window.oldClassName = newClassName;
$('body').toggleClass(newClassName);
}
You can use data attribute for the element, that is accessible using
$(element).data(attrib_name)
Just a small change is required in your method
function myToggle(newClassName) {
if (window.oldClassName) {
$('body').toggleClass(window.oldClassName);
}
window.oldClassName = newClassName;
$('body').toggleClass(newClassName);
}
can be replaced with
function myToggle(element, newClassName) {
if ($(element).data('oldClassName')) {
$(element).toggleClass($(element).data('oldClassName'));
}
$(element).data('oldClassName', newClassName)
$(element).toggleClass(newClassName);
}
Hope this solves it for you.
Update:
There is one thing you need to understand.
If you want two different behaviors you don't need 2 different classes for the change in behavior.
One is enough, because you can change the behavior based on weither the class is on or off.
Let's say I want my element to have a red hover event in one way.
And want it to have a blue hover event the other way with CSS.
Then this is the way to go:
$('#toggle').click(function(){
$('.normal').each(function(){
$(this).toggleClass('active');
});
});
JSFiddle Demo
Here we use a button to toggle all the divs and change their CSS behavior, looks easy now right?
However if you need to toggle Javascript/jQuery events as well this won't do. In that case you will need to use 3 other methods to manage this; .on(), .off(), and .hasClass().
$('#toggle').click(function(){
$('.normal').each(function(){
if($(this).hasClass('active')){
$(this).off('click');
} else {
$(this).on('click', function(){
alert('You are clicking on an active div.');
});
}
$(this).toggleClass('active');
});
});
JSFiddle Demo 2
As you can see we have added an if statement. If the element has the .active class we turn .off() the .click(). And if there isn't an active class we turn the .click() .on(). Under the if statement we always toggle the .active class. So this doesn't have to be placed inside the if statement.
I hope this clears everything up for you, good luck!
Old Answer:
It is better to use .toggleClass() here.
Use a first class on the element for the default properties and a second like .active for example for the interaction.
Also, using a .on('click', function(){}) bind will make you able to add interaction that will be bound instantly once the element is toggled.
Here's a fiddle: http://jsfiddle.net/NCwmF/2/
I little jQuery plugin for that. Removes the current smart class (if any) and adds the new smart class. If called without parameter className the current smart class gets only removed.
$.fn.smartToggle = function (className) {
var dataId = 'smartToggle';
return this.each(function () {
var $el = $(this);
$el
.removeClass($el.data(dataId) || '')
.addClass(className)
.data(dataId, className);
});
};
use it like every other jQuery method:
$('body').smartToggle('myClass');
NEW, SIMPLER ANSWER
Works similar to before, with 2 additions: 1.) works if there is no class initially and 2.) works if other functions change the elements class in between calls. I also changed the function name so it doesn't interfere with jQuerys native toggleClass.
$.fn.fancyToggleClass = function(new_class) {
return this.each(function() {
// get the last class this function added (if exists) or false (if not)
var $this = $(this),
toggled_class = $this.data('toggled-class') || false;
// if we dont have an original class, then set it based on current class
if (toggled_class) {
$this.removeClass(toggled_class);
}
// add new class and store as data,
// which we check for next time function is called
$this.addClass(new_class).data('toggled-class', new_class);
// alert the class, just as a check to make sure everything worked!
// remove this for production, or switch to console.log
alert('element class: ' + $this.attr('class'));
});
}
updated fiddle: http://jsfiddle.net/facultymatt/xSvFC/3/
OLD ANSWER
I would suggest storing the original class in the elements data attribute. Then, your function can check if this data is set, and if so clear the elements class adding the original class from the elements data and also the new class you passed in the function.
If data is not set, the function will store the current class as data the first time it runs.
Check out this fiddle for a working example with comments: http://jsfiddle.net/facultymatt/xSvFC/
here is the code. It's a jquery function so it can be called on any element (and is chainable too!)
$.fn.toggleClass = function(new_class) {
return this.each(function() {
// cache selector for this
$this = $(this);
// get original class (if exists) or false (if not)
var original_class = $this.data('original-class') || false;
// if we dont have an original class, then set it based on current class
if (!original_class) {
original_class = $this.attr('class');
$this.data('original-class', original_class);
// we do have an original class, so we know user is now trying to add class
// here we clear the class, add the original class, and add the new class
} else {
// assign the original class, and new class,
// and a space to keep the classes from becoming one
$this.attr('class', original_class + ' ' + new_class);
}
// alert the class, just as a check to make sure everything worked!
// remove this for production, or switch to console.log
alert('element class: ' + $this.attr('class'));
});
}
Hope this helps!
To avoid a global variable you can use data attribute as #ankur writes. Here is a working solution for your problem:
function myToggle(element, newClassName) {
if (!$(element).data('baseclassname')) {
$(element).data('baseclassname', $(element).attr('class'));
}
$(element)
.attr('class', $(element).data('baseclassname'))
.addClass(newClassName);
}
Does this do your job?
var smartToogle = function (element, preExistingClassName, newClassName) {
$(element)[0].className = preExistingClassName + ' ' + newClassName;
};
Just use hasClass. But you'll have to tell the function what both classes are:
function smartToggle(element, class1, class2) {
var $element = $(element);
if ($element.hasClass(class1)) {
$element.removeClass(class1);
$element.addClass(class2);
}
else {
$element.removeClass(class2);
$element.addClass(class1);
}
}
$(function(){
var smartToggle = function (element, newClassName) {
var elementClasses = element.attr('class');
element.addClass(newClassName);
// check if there is more than one class on the element
if(elementClasses .indexOf(' ') >= 0){
var oldClassNames = elementClasses.split(" ");
if (oldClassNames[oldClassNames.length - 1] !== newClassName) {
element.removeClass(oldClassNames[oldClassNames.length - 1]);
}
}
};
smartToggle($('.test'), 'newclass');
smartToggle($('.test'), 'newclass2');
});
Demo - http://jsfiddle.net/Q9A8N/ (look at the console to see what it is doing on each pass)
That should do what you want but as #T.J. Crowder said it is rather fragile and assumes that the class you want to remove is the last one on the element.
As an answer to your question, I would go with ankur's answer
As a follow-up to Sem's answer, regarding the handling of jQuery events :
you can use the on function to handle any jquery event from a parent node, based on a live filter :
function myToggle(element, newClassName) {
if ($(element).data('oldClassName')) {
$(element).toggleClass($(element).data('oldClassName'));
}
$(element).data('oldClassName', newClassName);
$(element).toggleClass(newClassName);
}
//event delegation : 'on' is called on the $('.divContainer') node, but we handle
//clicks on '.divItm' items, depending on their current class
$('.divContainer')
.on('click', '.divItm.plain', function(){ myToggle( this, 'red' ); })
.on('click', '.divItm.red', function(){ myToggle( this, 'blue' ); })
.on('click', '.divItm.blue', function(){ myToggle( this, 'plain' ); });
//initialize each item with the 'plain' class
myToggle( $('.divItm'), 'plain' );
Here is the jsFiddle.
You will note that the function called each time you click on an item depends on its "live" class, and that you don't need to manually enable/disable click handlers each time an item changes class.
You can learn more details from the documentation page.
var smartToogle = function (element, newClass) {
var $element = $(element),
currentClass = $element.data('toggle-class');
if (currentClass != newClass) $element.data('toggle-class',newClass).removeClass(currentClass || '');
$element.toggleClass(newClass);
};
or the other variant:
$.fn.smartToogle = function (newClass) {
currentClass = this.data('toggle-class');
if (currentClass != newClass) this.data('toggle-class',newClass).removeClass(currentClass || '');
this.toggleClass(newClass);
};
In this implementation you'll have to keep the a reference to this instance of fancytoggle.
var fancytoggle = function(el, oldClass){
// create a function scope so we'll have a reference to oldClass
return function(newClass) {
// toggle the old class and the new class
$(el).toggleClass(oldClass+ ' ' + newClass);
// update the new class to be the old class
oldClass = newClass;
};
};
for your example the code would look something like.
var bodytoggle = fancytoggle('body', 'pre-existing-class-name');
bodytoggle('new-class');
// 'new-class' replaces 'pre-existing-class-name'
bodytoggle('new-class-2');
// 'new-class-2' replaces 'new-class'
to see it in action refer to http://jsfiddle.net/aaf2L/6/
I am stuck on what to do when hiding a span that has a certain class name. I can't use this because it refers to the input. Here is my script:
//uncheck all checkboxes
$("input[type=checkbox]").prop("checked", false);
$("input[type=checkbox]").each( function (index) {
$(this).addClass("doc" + index);
})
$("input").change( function () {
var docName = $(this).parent().find("span");
var className = $(this).attr("class");
if(this.checked) {
$("span.noneAttached").fadeOut('slow', function () {
docName.clone().appendTo(".attachedDocuments").addClass(className).after("<br />").text();
});
}
else if (!this.checked && ($(".attachedDocuments > span").hasClass(className))) {
//hide the span with the class name
}
});
The else if checks to see if a checkbox is not checked and if the parent div contains any children with the class name. If so, hide it.
Where do I go from here? I am sure this answer is obvious, but I am just not seeing it.
Concatenate the class name to the selector like this
$("span."+className).hide();
Try this
$(".attachedDocuments span." + classname).hide();
$('.classname').hide();
$('.' + classnameasvariable).hide()
here's my code:
$(document).ready(function () {
$('.flip1').click(function () {
$('.panel1').slideToggle("slow");
});
$('.flip2').click(function () {
$('.panel2').slideToggle("slow");
});
$('.flip3').click(function () {
$('.panel3').slideToggle("slow");
});
$('.flip4').click(function () {
$('.panel4').slideToggle("slow");
});
});
I want to make a loop with .flip as the variable (flipVar) and .panel as (panelVar)
Well if it were my page I'd make sure that those elements all shared a class so that I wouldn't need to loop. However, you could do this:
for (var i = 1; i <= 4; ++i) $('.flip' + i).click((function(i) {
return function() { $('.panel' + i).slideToggle('slow'); };
})(i));
The loop variable has to be trapped in a closure so that each "click" handler references the proper value. Again, I really wouldn't do it this way. I'd make the "flip" elements share a class, and then keep that index (the implicit reference to a corresponding "panel") in a separate class element or in a "data-" attribute. Then the handler could find the panel using that value.
edit — as a hack, you could leverage the fact that the class names of the related elements are both of the form "somethingNN", where "NN" is the numeric part. You could strip off the number and then append it to "panel":
for (var i = 1; i <= 4; ++i) $('.flip' + i).click(function() {
var panelClass = this.className.replace(/.*\bflip(\d+).*/, "panel$1");
$(panelClass).slideToggle('slow');
});
Even though you want to run the selector in a loop, I wouldn't do it like that because you're doing multiple DOM selections. You can get it done with one DOM selection:
$(document).ready(function () {
$('div[class^=flip]').each(function ( idx ) {
$(this).click(function() {
$('.panel' + (idx + 1)).slideToggle("slow");
});
});
});
This will work assuming that the flip elements occur on the page in their numerical order.
This uses the attribute starts with selector to get all <div> elements that have a class name starting with "flip". Change the tag name if it is different, or remove it if they don't all have the same tag.
It uses the index that .each() makes available to you in order to toggle the correct .panel.
$(document).ready(function () {
for (var i=1; i<=4; i++) {
(function(i) {
$('.flip'+i).click(function () {
$('.panel'+i).slideToggle("slow");
});
})(i);
}
});
try this:
$(function(){
for(var i=1;i<5;i++){
$('.flip'+i).click(function () {
$('.panel'+i).slideToggle("slow");
});
}
});
PS:- don't use this it will not work as pointed out by #patrick