I want to hide all the elements on the page that end in _dropMenu via javascript...so this is what i have
window.onload = function() {
hideNav();
};
function hideNav(){
myArray = element("_dropMenu");// this is what need changing
for (i=0;i<=5;i++)
{
i.style.visibility = 'hidden';
}
}
This is obviously wrong but how do I first get all the elements on the page that end with _dropMenu then loop through them and set them to hidden... I would prefer javascript since I only have prototype on the page but if I need to add jquery I will...
jQuery has a selector for finding elements that have an attribute that ends with a given string:
$('[id$="_dropMenu]')
This will be faster if you can narrow it by an element type (e.g. if all the elements you care about are divs, or some such) but will work as is.
Behind the scenes, jquery is just looping through a given set of elements, and checking whether element["id"].substring(element["id"].length-"_dropMenu".length)==="_dropMenu".
Just pointing out the Prototype is very similar to jQuery in this case:
$$('[id$="_dropMenu"]').invoke('hide');
Kudos Jishnu & JacobM for getting the selector first.
Related
Is it possible to get all the elements from a webpage, and make a variable for each one? can you make variables within an each function and name them the same as their element name?
Yes, but be careful.
It is useful to store an element reference in a variable if it's present at load time and not changed later, but removing the div after load would cause your variable to return undefined. If the div is added after the variable is declared, you will also encounter an error.
Have a read here.
As you said, it's just for fun.. so I think that this should do the trick:
$("*").each(function() {
const elmnt = $(this);
const id = elmnt.attr("id");
if(id) {
window[id] = elmnt;
}
});
This will only create variables for the DOMs that have the id defined. But you can change the rule the way you want.
Use:
var div = $('div');
div.click();
If you wanted to bind the click event to all div elements you could easily just do:
var div = $('div');
div.click(function(){
//do something
});
A good way to shorten the jQuery selector and overhead and page performance is to use VanillaJS: http://vanilla-js.com/
Selecting object is one of the easiest thing to do with vanilla JS. I don't know what is your use case but a lot of what jQuery does is never used. If you are looking for optimization, try to live without it for a while and you might be surprised. Here are some out of the box ways to get elements in short variables.
Get all divs in your document:
var divs = document.querySelectorAll('div');
Get the first div only:
var div = document.querySelector('div');
Get a specific div:
var div = document.getElementById('somediv');
This way you can control everything (a la carte variables, rather than trying to solve all problems you might not need to solve).
I am writing a small library where I am in need of selecting a relative element to the targeted element through querySelector method.
For example:
HTML
<div class="target"></div>
<div class="relative"></div>
<!-- querySelector will select only this .target element -->
<div class="target"></div>
<div class="relative"></div>
<div class="target"></div>
<div class="relative"></div>
JavaScript
var target = document.querySelectorAll('.target')[1];
// Something like this which doesn't work actually
var relativeElement = target.querySelector('this + .relative');
In the above example, I am trying to select the .relative class element relative only to the .target element whose value is stored in target variable. No styles should apply to the other .relative class elements.
PS: the selectors can vary. So, I can't use JavaScript's predefined methods like previousElementSibling or nextElementSibling.
I don't need solution in jQuery or other JavaScript libraries.
Well it should be ideally:
var relativeElement = target.querySelector('.relative');
But this will actually try to select something inside the target element.
therefore this would only work if your html structure is something like:
<div class="target">
<div class="relative"></div>
</div>
Your best bet would probably in this case be to use nextElementSibling which I understand is difficult for you to use.
You cannot.
If you insist on using the querySelector of the subject element, the answers is there is no way.
The spec and MDN both says clearly that Element.querySelector must return "a descendant of the element on which it is invoked", and the object element you want does not meet this limitation.
You must go up and use other elements, e.g. document.querySelector, if you want to break out.
You can always override Element.prototype.querySelector to do your biddings, including implementing your own CSS engine that select whatever element you want in whatever syntax you want.
I didn't mention this because you will be breaking the assumption of a very important function, easily breaking other libraries and even normal code, or at best slowing them down.
target.querySelector('.relative');
By using querySelector on the target instead of document, you scope the DOM traversal to the target element.
It is not entirely clear from your explanation, but by related i assume you mean descendant?
To get all target elements you can use
document.querySelectorAll('.target')
And then iterate the result
I found a way which will work for my library.
I will replace "this " in the querySelector with a unique custom attribute value. Something like this:
Element.prototype.customQuerySelector = function(selector){
// Adding a custom attribute to refer for selector
this.setAttribute('data-unique-id', '1');
// Replace "this " string with custom attribute's value
// You can also add a unique class name instead of adding custom attribute
selector = selector.replace("this ", '[data-unique-id="1"] ');
// Get the relative element
var relativeElement = document.querySelector(selector);
// After getting the relative element, the added custom attribute is useless
// So, remove it
this.removeAttribute('data-unique-id');
// return the fetched element
return relativeElement;
}
var element = document.querySelectorAll('.target')[1];
var targetElement = element.customQuerySelector('this + .relative');
// Now, do anything with the fetched relative element
targetElement.style.color = "red";
Working Fiddle
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.
Looping through all the elements of the class, I see the code below only affecting the first element in the array yet the console log logs every one of them.
del = $('<img class="ui-hintAdmin-delete" src="/images/close.png"/>')
$('.ui-hint').each(function(){
console.log($(this));
if ($(this + ':has(.ui-hintAdmin-delete)').length == 0) {
$(this).append(del);
}
});
The elements are all very simple divs with only text inside them. They all do not have the element of the class i am looking for in my if statement, double checked that. Tried altering the statement (using has(), using children(), etc). Guess i'm missing something very simple here, haha.
Will apperciate input.
I think what you need is (also if del should be a string, if it is a dom element reference then you need to clone it before appending)
$('.ui-hint').not(':has(.ui-hintAdmin-delete)').append(function(){
//you need to clone del else the same dom reference will be moved around instead of adding new elements to each hint
return del.clone()
});
You can do this:
$('.ui-hint:not(:has(.ui-hintAdmin-delete))').append(del);
without even using the each loop here. As jquery code will internally loop through all the descendant of the ui-hint class element and append the del element only to the descendant not having any .ui-hintAdmin-delete elements.
While it would probably help to see your HTML as well, try changing your conditional to
if (!$(this).hasClass('ui-hintAdmin-delete')) {
$(this).append(del);
}
I have an element I populate with $.ajax now I want to fade all the custom loaded elements, the element is already pre-populated with 20 elements when the page loads, I don't want to target those 20. Essentially, how can I target the latter 17 divs assuming I have 37 divs total? Currently I use:
while ($(".info #future>center>div").length>20) {
$(".info #future>center>div:last-child").remove();
}
to remove them, but now I also want a fading effect to be applied prior, assigning anything to their class is not an option since that property is already taken.
you can use `slice() Slice() method of jquery. Given a jQuery object that represents a set of DOM elements, the .slice() method constructs a new jQuery object containing a subset of the elements specified by the start and, optionally, end argument. The supplied start index identifies the position of one of the elements in the set; if end is omitted, all elements after this one will be included in the result.
$('.info #future>center>div').slice(20).remove(); //Where start and end your index to filter. I omitted end parameter. if you want you can put it. .slice(20,37)
if you want fading effect
$('.info #future>center>div').slice(20).fadeOut(300, function() { $(this).remove(); });
take look on jQuery :gt() Selector.
it used to select all elements at an index greater than index provided to it so you can call it with index = 20
$(".info #future>center>div:gt(20)").remove();