I have four paragraph elements. I want to toggle the next even element after clicking on an odd element.
Here's the arrangement.
<p>First</p>
<p>Second</p>
<p>Third</p>
<p>Fourth</p>
So, if I click on First, I would like Second to be toggled; and if I click on third, I'd like the fourth element to be toggled. I hope it makes sense.
Here's what I have been able to come up with so far.
$("p:odd").click(function(){
$("p:even").toggle("slow");
});
Now, this piece of code toggles ALL the even elements. I just want to toggle n+1, whenever I click an odd paragraph. Does it make sense? Is there a way for that function to take an argument so that after clicking on an odd paragraph, the next (n+1) is toggled? I'm not really sure how to pass an argument or what would be the best way of doing it.
Thank you
Inside all of your Javascript and jQuery methods, the item that triggers the event is automatically passed to the function as this. However, because of the way that variable scope isn't enclosed in Javascript, this can change depending on what other functions are called inside. Best practice is to set this to another variable immediately.
So, you can adjust your method like this:
$("p:odd").click(function(){
var self = this;
// I'm doing .next('p') to make your code safer in case there's something between the <p> elements.
$(self).next('p').toggle('slow');
});
how about you try .next()? http://api.jquery.com/next/
$("p:odd").click(function(){
$(this).next().toggle('slow');
});
You can cache the objects and use eq method:
var $p = $('p'),
$odd = $p.filter(':odd'),
$even = $p.filter(':even');
$odd.click(function(){
$even.eq( $odd.index(this) ).toggle('slow');
});
http://jsfiddle.net/TLucC/ | http://jsfiddle.net/uNu9y/
Related
So I try to select a div within another div. My html goes like this:
<div id="Stage_game_page1"><div id="cube0">[...]</div><div id="cube1">[...]</div></div>
I want to select my #cube0 within my Stage_game_page specifically, with jQuery or JS.
The goal of the selection is to use it in an loop.
I tried :
var count =$("#Stage_game_page").children().length;
for(i=0; i<count;i++){
$("#Stage_game_page")$("#cube"+i)[...]
}
I don't understand what I'm doing wrong.
var count =$("#Stage_game_page").children().length;
for(i=0; i<count;i++){
$("#cube"+i);
}
This is sufficient to select the "#cube0"/"#cube1"/"#cube2" etc. especially since ids are always unique. To answer the question $("#cube0", "#Stage_game_page")... that is how you select a div in another div
The id attribute should only be used once! I see above that you're using id="cube0" twice. If you want your divs to be recognized in multiple instances, use a class instead (the . instead of the #). Using the same id twice will probably break your script.
I believe for your html, you could use id "cube0", "cube1", etc., as long as you're ok with entering them manually. That should work for the loop you'd like to use.
Loops through each div that starts with the id cube inside Stage_game_page1
$("#Stage_game_page1 > div[id^='cube']").each(function () {
alert($(this).html());
});
JSFiddle
Child Selctor
Starts with Selector
use each() for loop.
$('#Stage_game_page1').children().each(function(index) {
// your code here with index starts from 0
});
or this using jquery attribute starts with selector
$('#Stage_game_page1').find('[id^="cube"]').each(function(index) {
// your code here
});
You need to use .find() or .children() or the like.
The correct jQuery usage would be
$("#Stage_game_page").find('#cube'+i)
to find a div with that id inside the container #stage_game_page
You have duplicate cube0 in your html code..
and i think the look should contain something like that:
$("#cube"+i)[...]
One another solution is:
$("#Stage_game_page1 div[id='cube0']")
I've been using jQuery for a while but this is a new one. A simplified example:
HTML
<div class='custom'></div>
<div class='custom'></div>
<div class='custom'></div>
jQuery:
var $customElems = $('.custom'),
$spanOuter = $('<span class="outer"/>'),
$spanInner = $('<span class="inner"/>');
$customElems.each( function() {
$(this).wrap($spanOuter).after($spanInner);
});
JSFiddle:
http://jsfiddle.net/a3ZK8/
I would have expected the 'inner' span to be added to all three elements in the selection but it gets always inserted into the last one only (no matter how many). I tried it with .before(), with and without the chaining, same result. What am I missing??
The problem is you are using a reference to a jQuery object.
Hence you keep moving the object reference around within each iteration.
If you have no events attached or no need for the span to be a jQuery object then just pass the parameter as a HTML string literal instead of an object reference
Cloning a jQuery object that doesn't need to be a jQuery object in the first place is just redundant processing and unnecessary overhead.
Change your jQuery object to a string similar to this:
spanInnerString = '<span class="inner"/>';
and your method like this:
$(this).wrap($spanOuter).after(spanInner);
The result is:
<span class="outer"><div class="custom"></div><span class="inner"></span></span>
<span class="outer"><div class="custom"></div><span class="inner"></span></span>
<span class="outer"><div class="custom"></div><span class="inner"></span></span>
DEMO - Passing parameter as HTML string
Off course, the same goes for the outer span. Don't create jQuery objects unless you have to.
If you must use a jQuery object because you want to attach events to the span or similar, than cloning is the way to go, though make sure you use clone(true, true) then to also clone the attached events.
You need to clone the element. Otherwise, after() will relocate the same element 3 times, which results in it being attached to only the last looped element.
$customElems.each(function () {
$(this).wrap($spanOuter).after($spanInner.clone());
});
Demo: Fiddle
You might ask, "Why would wrap() work?" That's because 'wrap()' internally clones the element.
You're moving the same span from place to place. If you acted on all three divs at once, jquery will instead clone the span.
http://jsfiddle.net/a3ZK8/1/
var $customElems = $('.custom'),
$spanOuter = $('<span class="outer"/>'),
$spanInner = $('<span class="inner"/>');
$customElems.wrap($spanOuter).after($spanInner);
From the documentation for .after:
Important: If there is more than one target element, cloned
copies of the inserted element will be created for each target except
for the last one.
which means the last element will always get the original, while all other selected elements will get a clone. That's why when you acted on one element at a time, it simply moved the same span around.
Here's how I append the value:
$('<div>someText</div>').appendTo(self);
And here's how I want to remove it:
$(self).remove('<div>someText</div>');
The appending works, the removing doesnt. What am I doing wrong?
The .remove() function takes a selector to filter the already matched elements, not to match elements inside of them. What you want is something like this:
$(self).find('div:contains(someText)').remove();
That will find a <div> element containing the text someText inside of whatever element self is, then removes it.
The API http://api.jquery.com/remove/ sais that a selector is required.
Try $(self).remove('> div');
This will remove the first childs of div.
You can use $(self).filter('div:contains("someText")').remove(); to remove a div with a specific content or $(self).find('> div').remove(); to remove the first childs of div.
EDIT: removed first version I posted without testing.
It most likely has to do with the scope of self. Since you've named it self I am assuming that you are getting this variable using $(this) on the click event. If that's the case, and you want to call the remove method, you can only do so from within the same function. Otherwise you need to either store the element in a variable or provide another selector to access it.
Example:
<div class="div1"></div>
this will be the div with the click event
$(document).ready(function(){
var self = null;
$('.div1').click(function(e){
self = $(this);
var itemToAdd = '<div>SomeText</div>';
$(itemToAdd).appendTo(self);
});
// to remove it
// this will remove the text immediately after it's placed
// this call needs to be wrapped in a function called on another event
$('.div1').find('div:contains(someText)').remove();
});
I have a small problem with a jQuery script I wrote.
I have an HTML structure like this:
<div id="navigation">
<ul>
<li><b>Text1</b></li>
<li><b>Text2</b></li>
...
</ul>
</div>
Then, I have a click function binded to those li/a tabs that sets the value of the current page to href:
var currentpage = $(this).attr('href');
And, finally, an update function that is fired when it's needed that do many thing, but also changes the style of the currently selected li/a tab:
$('#navigation a').each(function()
{
var tab = $(this);
tab.parent().toggleClass('current', (tab.attr('href') == currentpage));
});
Everything works fine, but today I was trying to rewrite the last function on one line only -without calling each()- and I can't get it to work.
I've tried many solutions like:
$('#navigation a').parent().toggleClass('current', ($(this).children(':first').attr('href') === currentpage));
$('#navigation a').parent().toggleClass('current', ($(':only-child', $(this)).attr('href') == currentpage));
Can someone help me out?
Thanks!
You can't rewrite it as you'd like to.
The original code has to use ".each()" because it needs access to each individual <a> element in order to do its thing. In your rewrite, you're imagining that you can get this set to each element being processed, but that's just not how this works in JavaScript. In your attempted rewrite, the value of this in those parameters to "toggleClass()" will be this as it stands outside that entire jQuery function call chain. It'll have absolutely nothing to do with the <a> elements being processed by the call to "toggleClass()".
when your function is triggers i.e. on clicking the in that function you can get the reference to the clicked element, tag by using $(this). Then your code should be
$(this).parent().toggleClass('current', ($(this).children(':first').attr('href') === currentpage));
I am not very sure with the use of "this" [current context] in jquery.What I know is- it prevents the dom from searching all the elements, it just work on that current element, which improve performance[correct me if I am wrong].Also I am not sure when to use this and when not.
lets say, should I go for
$("span",this).slice(5).css("display", "none")
or
$("span").slice(5).css("display", "none")
both will work, but I am not very clear as how really it works.can somebody explain it with a diff/proper example, and when to use what?
[EDIT]
$(function() {
$("#clickme").click(function() {
$("span",this).slice(5).css('display', 'block');//doesn't work ? why?
$("span").slice(5).css('display', 'block');//works..why?
});
});
enter code here <span id="clickme">Click me</span>
<span>itam1</sapn>
<span>itam2</sapn>
<span>itam3</sapn>
<span>itam4</sapn>
<span>itam5</sapn>
...upto10
Usually you can use the this keyword on event handlers since it will be a reference to the element that triggered the event and other jQuery functions like $.each.
For example when handling a click event lets say:
$('.parentElement').click(function () {
$('.foo', this).hide();
});
The above code, will hide all the elements with class foo that are descendants of the currently parentElement that was clicked.
The use of the context argument of the jQuery function is the equivalent of making a call to the find method:
$(expr, context);
// is just equivalent to:
$(content).find(expr);
EDIT: Looking at your example:
$("#clickme").click(function() {
$("span",this);//... (1)
$("span");//.. (2)
});
The first line, will look for all the span elements that are inside of #clickme (its descendants), since that element was the one that triggered the click event.
The second line, will look for all the span elements on the whole page.
How it works
Lets use this HTML for the examples:
<div id="container">
<div class="column">Link 1</div>
<div class="column">Link 2</div>
</div>
<div id="footer">
Link 3Link 3
</div>
The scoping parameter of the jQuery function should only be used if you already have a cached reference to a DOM element or jQuery wrapped element set:
var $set = $('#container');
$('a', $set).hide(); // Hides all 'a' tag descendants of #container
Or in an event:
$("#container").click(function(e){
$('a', this).hide(); // Same as call above
}
But it makes no sense to use it like this:
$('a', '#container').hide()
When it should be written like this:
$('#container a').hide();
Having said all that, it is generally cleaner and clearer to just use .find() instead of using the second parameter in the jQuery function if you already have the jQuery or DOM element. The first example I gave would be written this way instead:
var $set = $('#container');
$set.find('a').hide(); // Hides all 'a' tag descendants of #container
If this one call was the only reason you grabbed the #container object, you could also write it this way since it will still scope the search to the #container element:
$("#container a").hide(); // This is the same as $('a', "#container");
Why would you scope your selections
When jQuery looks for an unscoped selector, it will search through the entire document. Depending on the complexity of the selector, this could require a lot of searching. If you know that the element you are looking for only occurs within a specific parent, it will really speed up your code to scope the selection to that parent.
Regardless of what method of scoping you choose, you should always scope your selectors whenever possible.