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$(selector).exists() would be a nice addition!
in Using jQuery
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11 years ago
I think, 
- $(selector).exists();
would be a nice method to replace this condition:
- if( $(selector).length > 0 ) {...
- if( $(selector).exists() ) {...
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Re: $(selector).exists() would be a nice addition!
11 years ago
- $.fn.exists = function() {
- return this.length > 0;
- }
Edit: i think you can also do .is('*'), should return false if no elements are selected.
-- Kevin
------------------------------------------------
http://www.tentonaxe.com - jQuery Snippets and Tutorials
I know how to extend the jQuery to include this method, but it would be nice as a native method included in the jQuery file. Right?
i'm not sure, you can already get that functionality with a method currently in jquery core, it just doesn't read the same.
.is is implemented like this:
- if ( $( selector ).is( "*" ) ) {...
.is is implemented like this:
- is: function( selector ) {
- return !!selector && jQuery.filter( selector, this ).length > 0;
- },
- exists: function( selector ) {
- return !!selector ? jQuery.filter( selector, this ).length > 0 : this.length > 0;
- }
Edit: i guess what i'm getting at is you can get the same functionality from a different method that wasn't made to implement this kind of functionality, so it sortof makes sense to add it, but at the same time, it is such a simple method, i'm not sure if it is even worth adding. .is does reduce the amount of code you would ahve to write to get the same result significantly, while .exists() would not be reducing the code by very much( if at all ).
-- Kevin
------------------------------------------------
http://www.tentonaxe.com - jQuery Snippets and Tutorials
------------------------------------------------
http://www.tentonaxe.com - jQuery Snippets and Tutorials
Leave a comment on Kevin B's reply
Re: $(selector).exists() would be a nice addition!
11 years ago
I suggested this some time ago: http://bugs.jquery.com/ticket/3842.
Leave a comment on kbwood.au's reply
Re: $(selector).exists() would be a nice addition!
11 years ago
Thanks kbwood.au, I hadn't seen your ticket before!
So that means, my idea is not useless!
Leave a comment on sojaner's reply
Re: $(selector).exists() would be a nice addition!
11 years ago
Just a little remark: "$(selector).length" is enough, you don't have to write "$(selector).length > 0".
But of course "length" is not as clear as "exists"
But of course "length" is not as clear as "exists"
Leave a comment on north's reply
Re: $(selector).exists() would be a nice addition!
11 years ago
tentonaxe, there are many jQuery plugins and utilities that do not reduce the amount of code you write, let's say:
- $.flashembed(............)
- and
- flashembed(............)
And also, I exactly mean:
- var booleanData = $.("#Something").exists();
This code is really elegant in my opinion but using .is() is not so much elegant is this case!
And also, it is not so big but usable to be added to the jQuery's core methods.
Leave a comment on sojaner's reply
Hi there,
If you ask me (and for the sake of discussion I'll act like you did) I'd say;
I don't really get why all code should be "sexy" and "elegant" were not talking about women here, were talking about JavaScript.
In my opinion "sexy" and "elegant" are too subjective to take into account when looking at code.
The most important thing is efficiency and legibility, not only for yourself but also for other people who read your code, be it in a team of coders or somewhere else.
Checks to find out if an element exist are available in vanilla JavaScript for ages, why not use those?
They're native so they're extremely fast, they are legible and everyone who reads your code (should) know(s) what it means.
Given the circumstance where you would like to see if a certain id is in the DOM just use
And when you pass this code through Closure Compiler and use certain coding standards like :
So that kinda levels the playing field download size wise.
The letters you write are not the only thing that matter when it comes to JavaScript, it's also a lot about what the framework has to write to let you write it the way you would want it to be written.
All with its own overhead.
Best practices, ok. but when you start to value code on the "sexyness" of it I think your making it harder for everyone.
Besides, one of the things I value greatly about jQuery is the fact that its not bloated with stuff you can do easily with vanilla JavaScript, especially since vanilla (when its cross browser compatible) is always faster than framework code.
This in my opinion only bloats the jQuery code-base.
Just my two cents...
Superficial.
If you ask me (and for the sake of discussion I'll act like you did) I'd say;
I don't really get why all code should be "sexy" and "elegant" were not talking about women here, were talking about JavaScript.
In my opinion "sexy" and "elegant" are too subjective to take into account when looking at code.
The most important thing is efficiency and legibility, not only for yourself but also for other people who read your code, be it in a team of coders or somewhere else.
Checks to find out if an element exist are available in vanilla JavaScript for ages, why not use those?
They're native so they're extremely fast, they are legible and everyone who reads your code (should) know(s) what it means.
Given the circumstance where you would like to see if a certain id is in the DOM just use
- if (document.getElementById("isItInTeDOM")) {
- dostuff...
- }
- if ($("#isItInTheDOM").length) {
- dostuff...
- }
And when you pass this code through Closure Compiler and use certain coding standards like :
- (function (window, document, $, undefined) {
- execute all your code here
- })(window, document, jQuery)
So that kinda levels the playing field download size wise.
The letters you write are not the only thing that matter when it comes to JavaScript, it's also a lot about what the framework has to write to let you write it the way you would want it to be written.
All with its own overhead.
Best practices, ok. but when you start to value code on the "sexyness" of it I think your making it harder for everyone.
Besides, one of the things I value greatly about jQuery is the fact that its not bloated with stuff you can do easily with vanilla JavaScript, especially since vanilla (when its cross browser compatible) is always faster than framework code.
This in my opinion only bloats the jQuery code-base.
Just my two cents...
Superficial.
and adding to this same concept of using native javascript, you can do this which uses jquery to select the elements, then checks to see if the element in the first position is defined.
-- Kevin
- if ($("#isItInTheDom")[0]) {
- dostuff...
- }
this allows you to easily select a group of elements by class and confirm that atleast 1 element is selected. If you want to check for atleast 2, or atleast 3, just change the 0 to a 1, 2, 3, etc.
-- Kevin
Leave a comment on superficial's reply
Re: $(selector).exists() would be a nice addition!
11 years ago
Don't you have a library of common functions that you are likely to use all the time?
In my "utils.js" file, I keep an exists() function for jQuery that allows me to write "sexy" code the way you like. It doesn't take too much time to call the function and if it does, I'll just use $( selector ).is( "*" )
I say lets strip jQuery's core down as much as we can and implement your own customizations to meet your programming style. But that's just my opinion.
jase
Leave a comment on Pork's reply
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