Why my jQuery extension's function act "static"? - javascript

I made a custom jQuery extension to handle files for upload.
My stripped version: http://jsfiddle.net/6huV6/
My full version: http://jsfiddle.net/LQrJm/
My problem is that buildBondye is called 2 times, but my extension is added 2 x 2 droppers and buttons..
How do I fix this?

You get four because for each element in your set of matched elements you're calling the buildBondye function, which in turn calls the addButton and addDropper functions. Those functions use $this, which is the entire set of matched elements (so both of them), not only the element for that iteration of .each().
You can fix this by passing a reference to a single element to those two functions, and using that instead:
var buildBondye = function () {
// inside buildBondye this refers to the specific element for the iteration of .each()
// different to the this inside the $.fn.bondye function
addButton(this);
addDropper(this);
}
var addDropper = function (element) {
$dropper = $('<input type="text" readonly />');
$dropper.val('drop here');
$(element).after($dropper);
}
var addButton = function (element) {
$button = $('<input type="button" />');
$button.val('browse');
$button.bind('click', function () {
$(element).trigger('click');
});
$(element).after($button);
}
Take a look at this updated jsFiddle.

Related

Passing the correct context to a function with arguments from ready function

I have spent a day trying to find the way to pass the correct context to the removeForm. The goal is to use the removeForm which is called when pressing <a class="remove_2"> remove </a> link to remove the content of the class passed to removeForm in this case "subform2". Here is what I tried:
function removeForm(tgsubf) {
var $removedForm = $(this).closest(tgsubf);
var removedIndex = parseInt($removedForm.data('index'));
$removedForm.remove();
}
$(document).ready(function() {
$('.remove_2').click(function(e){
e.preventDefault();
removeForm('.subform2')
});
}
<div class="subform2">
<a class="remove_2"> remove </a>
</div>
I know that the context depends on how I call the function but also if I call the function using removeForm('subform2') I still have this problem.
The full example is hosted here.
If you want to remove the .subform2 element that contains the .remove_2 which was clicked, you can do the following.
When your are inside an event callback you pass to jQuery, this (generally) holds the element that received the event. So you should change your code to have the following:
$('.remove_2').click(function(e){
e.preventDefault();
removeForm(this) // <-- 'this' will refer to $('.remove_2')
});
Then you can change your removeForm() to get the immediate ancestor of the element passed to it (which would be .remove_2) that has .subform2 for class and remove it, like this:
function removeForm(anchor) {
var $removedForm = $(anchor).closest('.subform2');
$removedForm.remove();
}
UPDATE
You should be able to pass a selector to removeForm to identify the ancestor, like this:
function removeForm(el, ancestorSelector) {
// Do check to ensure ancestorSelector is provided, before using it.
var $removedForm = $(el).closest(ancestorSelector);
$removedForm.remove();
}
You can update how you call it like this:
$('.remove_2').click(function(e){
e.preventDefault();
removeForm(this, '.subform2') // <-- 'this' will refer to $('.remove_2')
});

Select element by passing variable in function - jQuery

I am trying to select all input fields inside a certain element. I pass this element to a function, but I don't know how to go from there:
$('._save, .btn-success').click(function(){
saveForm($('.dashboard_container'));
});
//This functions has to select all the input fields inside the given element
function saveForm(that) {
var input = $(that, 'input'); //This does not seem to work
input.each(function(){
//Do something
})
}
How to chain a variable and a selector together?
The contextual selector takes the parameters the other way around to what you've used:
function saveForm($that) {
var $input = $('input', $that);
$input.each(function(){
//Do something
})
}
You could also use the find() method as you're passing in a jQuery object:
var $input = $that.find('input');
If you need to find all input field inside some element x then you can use .find(input).
For example:
//This functions has to select all the input fields inside the given element
function saveForm(that) {
var input = $(that).find("input"); //This does not seem to work
input.each(function(){
//Do something
})
}
And you can achieve it without using .find as well (the way you were trying to do)
$('._save, .btn-success').click(function(){
saveForm('.dashboard_container');
});
//This functions has to select all the input fields inside the given element
function saveForm(that) {
var input = $(that + ' input'); //This does not seem to work
input.each(function(){
//Do something
})
}

A smart toggle class in jQuery

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/

Is there an easier way to reference the source element for an event?

I'm new to the whole JavaScript and jQuery coding but I'm currently doing this is my HTML:
<a id="tog_table0"
href="javascript:toggle_table('#tog_table0', '#hideable_table0');">show</a>
And then I have some slightly ponderous code to tweak the element:
function toggle_table(button_id, table_id) {
// Find the elements we need
var table = $(table_id);
var button = $(button_id);
// Toggle the table
table.slideToggle("slow", function () {
if ($(this).is(":hidden"))
{
button.text("show");
} else {
button.text("hide");
}
});
}
I'm mainly wondering if there is a neater way to reference the source element rather than having to pass two IDs down to my function?
Use 'this' inside the event. Typically in jQuery this refers to the element that invoked the handler.
Also try and avoid inline script event handlers in tags. it is better to hook those events up in document ready.
NB The code below assumes the element invoking the handler (the link) is inside the table so it can traverse to it using closest. This may not be the case and you may need to use one of the other traversing options depending on your markup.
$(function(){
$('#tog_table0').click( toggle_table )
});
function toggle_table() {
//this refers to the element clicked
var $el = $(this);
// get the table - assuming the element is inside the table
var $table = $el.closest('table');
// Toggle the table
$table.slideToggle("slow", function () {
$el.is(":hidden") ? $el.text("show") : $el.text("hide");
}
}
You can do this:
show
and change your javascript to this:
$('a.tableHider').click(function() {
var table = $(this.name); // this refers to the link which was clicked
var button = $(this);
table.slideToggle("slow", function() {
if ($(this).is(':hidden')) { // this refers to the element being animated
button.html('show');
}
else {
button.html('hide');
}
});
return false;
});
edit: changed script to use the name attribute and added a return false to the click handler.
I'm sure this doesn't answer your question, but there's a nifty plugin for expanding table rows, might be useful to check it out:
http://www.jankoatwarpspeed.com/post/2009/07/20/Expand-table-rows-with-jQuery-jExpand-plugin.aspx

Passing in parameter from html element with jQuery

I'm working with jQuery for the first time and need some help. I have html that looks like the following:
<div id='comment-8' class='comment'>
<p>Blah blah</p>
<div class='tools'></div>
</div>
<div id='comment-9' class='comment'>
<p>Blah blah something else</p>
<div class='tools'></div>
</div>
I'm trying to use jQuery to add spans to the .tools divs that call variouis functions when clicked. The functions needs to receive the id (either the entire 'comment-8' or just the '8' part) of the parent comment so I can then show a form or other information about the comment.
What I have thus far is:
<script type='text/javascript'>
$(function() {
var actionSpan = $('<span>[Do Something]</span>');
actionSpan.bind('click', doSomething);
$('.tools').append(actionSpan);
});
function doSomething(commentId) { alert(commentId); }
</script>
I'm stuck on how to populate the commentId parameter for doSomething. Perhaps instead of the id, I should be passing in a reference to the span that was clicked. That would probably be fine as well, but I'm unsure of how to accomplish that.
Thanks,
Brian
Event callbacks are called with an event object as the first argument, you can't pass something else in that way. This event object has a target property that references the element it was called for, and the this variable is a reference to the element the event handler was attached to. So you could do the following:
function doSomething(event)
{
var id = $(event.target).parents(".tools").attr("id");
id = substring(id.indexOf("-")+1);
alert(id);
}
...or:
function doSomething(event)
{
var id = $(this).parents(".tools").attr("id");
id = substring(id.indexOf("-")+1);
alert(id);
}
To get from the span up to the surrounding divs, you can use <tt>parent()</tt> (if you know the exact relationship), like this: <tt>$(this).parent().attr('id')</tt>; or if the structure might be more deeply nested, you can use parents() to search up the DOM tree, like this: <tt>$(this).parents('div:eq(0)').attr('id')</tt>.
To keep my answer simple, I left off matching the class <tt>"comment"</tt> but of course you could do that if it helps narrow down the div you are searching for.
You don't have a lot of control over the arguments passed to a bound event handler.
Perhaps try something like this for your definition of doSomething():
function doSomething() {
var commentId = $(this).parent().attr('id');
alert(commentId);
}
It might be easier to loop through the comments, and add the tool thing to each. That way you can give them each their own function. I've got the function returning a function so that when it's called later, it has the correct comment ID available to it.
The other solutions (that navigate back up to find the ID of the parent) will likely be more memory efficient.
<script type='text/javascript'>
$(function() {
$('.comment').each(function(comment) {
$('.tools', comment).append(
$('<span>[Do Something]</span>')
.click(commentTool(comment.id));
);
});
});
function commentTool(commentId) {
return function() {
alert('Do cool stuff to ' + commentId);
}
}
</script>
Getting a little fancy to give you an idea of some of the things you can do:
var tool = $('<span>[Tool]</span>');
var action = function (id) {
return function () {
alert('id');
}
}
$('div.comment').each(function () {
var id = $(this).attr('id');
var child = tool.clone();
child.click(action(id));
$('.tools', this).append(child);
});
The function bind() takes, takes the element as a parameter (in your case the span), so to get the id you want from it you should do some DOM traversal like:
function doSomething(eventObject) {
var elComment = eventObject.parentNode.parentNode; //or something like that,
//didn't test it
var commentId= elComment.getAttribute('commentId')
alert(commentId);
}

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