What is alternative to jQuery(this) in YUI 3? - javascript

I have started coding in yui and already have good knowledge of jQuery ,
I need some information about migrating from jQuery to yui.
What is the alternative to jQuery(this) in YUI?

In most cases, jQuery(this) is done inside event callbacks to wrap the subscribed element with the jQuery API. In YUI3, that's done for you automatically. The this in event callbacks is the Node instance that was subscribed from.
Y.one('#readygo').on('click', function (e) {
this.append("<p><code>this</code> is already a YUI 3 wrapped Node instance.</p>");
});

You may find JS Rosettastone useful. I found it invaluable when I moved to YUI 3 and I will not move back.

Related

What was the "undocumented and incredibly non-performant way to monitor setting and getting of values"?

The jQuery Core 1.9 Upgrade Guide says, ".data() method had an undocumented and incredibly non-performant way to monitor setting and getting of values that was removed in 1.9."
What was this?
I'm not asking so I can use it, but so I can grep and make sure it's not used (I'm fairly certain it's not in my code base, but perhaps someone else's code does have it without them knowing.).
I think we're talking about event monitoring here. Try this:
<span id="fapfap">fap</span>
<script>
$(function(){
$("#fapfap").click(function(){
$(this).text($(this).text()+"fap")
});
console.log($("#fapfap").data("events.click"));
});
In older jq versions you'll see an event object

Can I combine jQuery with Javascript?

I want to use the Javascript selector document.querySelector insted of $ or jQuery jQuery selector but I want to combine the Javascript selector with jQuery functions (like .getJSON(), .html(), .append() , etc.).
For example:
$.getJSON("list.json", function(data) {
document.querySelector("#content").html(data.name);
});
Here when I use the document.querySelector I get Uncaught TypeError: undefined is not a function and when I use $ I don't get any error.
jsFiddle Test
Is it possible to run jQuery and Javascript together?
Thanks!
Off couse yes! It is possible to run jQuery and JavaScript together in you application.
All you need to know is, which is a JavaScript Object when trying to run some methods of it. jQuery can be handy sometimes. But, yes! You can work with them together.
Secondly, remember that jQuery is a JavaScript's Library. It isn't anything other than JS. To be simple, jQuery needs JavaScript to run. JavaScript doesn't need jQuery to run.
From this MDN source, it is stated that you can use that method just the way it is.
document.querySelector(".someclass");
https://developer.mozilla.org/en-US/docs/Web/API/document.querySelector
All you now need to make sure is of that, that class you're trying to access exists.
$.getJSON("list.json", function(data) {
$(document.querySelector("#content")).html(data.name);
});
PS:
But there isn't any sense to use it everywhere. Check the #afzaal-ahmad-zeeshan answer & read how to use native functional of DOM elements. jQuery isn't a panacea.
jslayer's answer gave me an idea, which seems to work.
Wrapping js code in $() seems to work (though I'm not sure why).
For example, to use slideToggle() (which is only available in jQuery, I think), doing
event.target.nextElementSibling.slideToggle()
does not work, but
$(event.target.nextElementSibling).slideToggle()
does.

Firing events in FireBreath

I am writing a wrapper class for an activex control using a FireBreath plugin.
In the FireBreath activex wrapper example linked to from the documentation of FireBreath the author of the project uses FireEvent to asynchronously fire the event from the activex container class.
But the documentation of FireBreath now has a note under the method FireEvent which says:
"Note: Firing events in this manner is deprecated as of FireBreath 1.5.0"
And also in the example the events are not registered in the root JSAPI object using this format:
FB_JSAPI_EVENT()
So is this the right way of doing it? Or is it possible to call the events from the container class using the
fire_event()
method?
Both work the same way, the reason that calling FireEvent directly is deprecated is just that it's easier to make mistakes with the parameters you pass in.
You can use either method, but I recommend that you use FB_JSAPI_EVENT simply to keep things more clear.

Finding if a jquery plugin/function is available. Diff between $.pluginName() and $().pluginName()

I am trying to detect if a jQuery plugin is available, I tried
$.pluginName
but failed then tried
$().pluginName
it works. But whats the difference between the 2?
You should be looking at $.fn.pluginName. jQuery's $.fn is an alias for $.prototype and that's where all the plugin names go. The top-level $.* namespace is reserved for jQuery's utility functions such as $.each() and $.grep().
You can look at this stackoverflow question only, they discussed a lot about this
How can I check if a jQuery plugin is loaded?

prototype and jQuery peaceful co-existence?

I know very little about JavaScript but despite this I'm trying to cobble something together on my wordpress blog. It's not working, and I don't know how to resolve it, and hey, that's what StackOverflow is for, right?
Firstly, the error message is:
Error: element.dispatchEvent is not a function
Source File: http://.../wp-includes/js/prototype.js?ver=1.6
Line: 3936
It happens on page load. My page load handler is registered thusly:
Event.observe(window, 'load', show_dates_as_local_time);
The error goes away if I disable some other plugins, and this (plus googling) led me to conclude that it was a conflict between prototype and jQuery (which is used by some of the other plugins).
Secondly I'm following the wordpress recommended practice of using wp_enqeue_script to add a dependency from my JavaScript to the Prototype library, as follows:
add_action( 'wp_print_scripts', 'depo_theme_add_javascript' );
function depo_theme_add_javascript() {
wp_enqueue_script('friendly_dates', 'javascript/friendly_dates.js', array('prototype'));
}
Now I'm also aware that there are some potential conflicts between jQuery and Prototype which are resolved using the jQuery noConflicts method. I've tried calling that from various places but no good. I don't think this is the problem because a) the noConflict function relates solely to the $ variable, which doesn't seem to be the problem here, and b) I would expect wordpress to sort it out for me because it can...
Lastly, using the Venkman debugger I've determined that the element referenced in the error message is indeed an HTMLDocument but also does lack a dispatchEvent. Not sure how this could happen, given it's a standard DOM method?
There is a nasty trick many libraries do that I've taken a distinct liking to, and it looks like prototype is one of these.
Mootools does this, If I am right, and it involves overloading many of the prototypes on the basic classes, monkey patching them.
And likewise, I similarly encountered strange behaviour when mootools and jQuery were present, usually jQuery dying because it was calling some object method which had been somehow overloaded/monkey patched by Mootools.
Also, mysteriously, taking mootools out of the script usage list, resulted in everything running much faster, which I concluded was due to less object pollution.
Now I could be wrong, but I concluded from my experience such libraries just simply don't like to co-exist with each other, and seeing how mootools code seemed to me to degrade speed at which normal things were done, I sucked up and ported all mootools based code to jQuery ( A time consuming deal I assure you ), and the result, was code that was fast and didn't have weird errors that were unexplainable.
I recommend you consider migration as at least One of your options.
One More thing, when writing:
I tend to use this syntax with all my jQuery driven code, for a bit of safe encapsulation in the event somebody breaks '$' somehow.
Runtime Code
This waits for document.ready before executing:
jQuery(function($){
code_with_$_here;
});
jQuery Plugins
(function($){
code_with_$_here;
})(jQuery);
Using these will make it easier for people using any jQuery you happen to write to be able to use it without much of a conflict issue.
This will basically leave them to make sure their code isn't doing anything really magical.
Its worth reading this article on the JQuery site about Using JQuery With Other Libraries. It deals with more than just the noConflict option.
I think you should search well because all jQuery plugins has a prototype version and all prototype plugins has a jQuery version.
If you really don't find what you look and you can't use only one library, take a look here at
jQuery.noConflict();
But again, i think it make no sense to load over 15-20kb for each library :)
Thanks for the suggestions all. In the end I think Kent's explanation was the closest, which basically amounted to "Prototype is broken". (Sorry if I'm summarizing you incorrectly :)
As for the jQuery.noConflict option - I already mentioned this in the question. It makes a difference when you run this method, and I have very little control over that. As I said, I have tried running it in a couple of different places (specifically the page header and also from my script file), to no effect. So, much as we'd all like it to be, "just use noConflict" is not an answer to this question, at least not without additional information.
Besides, jQuery.noConflict seems to be about the $ variable, and the code around the error point does not deal with that variable at all. Of course they could be related indirectly, I haven't tracked it down.
So basically I ended up rewriting the script using jQuery instead of Prototype, which actually had its own problems. Anyway I've published the whole war story on my blog, should you be interested.

Categories