Can someone explain the new trend to not use jQuery?
jQuery as a library has now become huge, and a lot of projects probably don't use the full feature set. With modern browser support converging and older browsers being edged out of the usage stats, there's not as much need for the cross-browser portions of the library anymore. Enough so that newer versions of jQuery have dropped support for those browsers as well.
So if you can cut down your cold cache loading times by not including the full jQuery library, that's probably a win (especially on mobile). You can do this by using a custom build of jQuery, but I guess some developers are taking this opportunity to go "back to their roots" and see how Javascript has changed since jQuery became a de-facto include in every project.
I think there's a lot more maturity in the language these days, and by using native JS methods there's probably opportunities there for browser optimisations that aren't available using helper methods written in JS that accomplish the same functional goals.
But I'm not a browser devevloper or a JavaScript expert, just a long time web developer who remembers the times before jQuery was in every project. If it's a crutch, it's one I will remember fondly.
> jQuery as a library has now become huge
> So if you can cut down your cold cache loading times by not
> including the full jQuery library, that's probably a win
jQuery 2.1.4 is 34.1 KB when minified and gzipped.
I'm all for eliminating unnecessary bloat, but it's not as if a jQuery download is a huge amount of data to fetch. While jQuery is not a framework, most front-end JS frameworks are the same size or bigger and don't receive as much attention for being bloated.
If you can get by without jQuery, or if you have a very large number of mobile users and first-load performance is mission-critical for your application, or if you have a large percentage of users from countries with slow or intermittent internet connections, then sure, avoiding jQuery makes sense as a priority. But for most applications, jQuery is a smaller download than a single medium-resolution highly optimized image, and it can be cached forever.
Your comparison with "a single medium-resolution highly optimized image" doesn't hold for mobile phones. On mobile phones users expect latency when loading images, but not when loading the UI. Another problem is that JQuery is not the only commonly used library. You add Underscore, you add Angular, or whatever libraries du-jour we have and pretty soon we are talking about 100 Kb of stuff or even more that is rarely used as a whole.
Of course, my use-case is about having really simple interfaces augmented by Javascript and meant for mobile phones. Well, for complex interfaces I think bringing in JQuery as a dependency may be worth it, but then again, I then start thinking that JQuery is not enough. It's because I want more, I want a virtual DOM that's saner by design, I want to work with immutability, I want much better performance without unpredictable behavior (like what you get with Angular) and I want to only pay for the features I use. JQuery is incompatible with React and is incompatible with Google Closure in advanced mode.
I also agree that jQuery isn't the end of what gets added... once you add a few additional libraries it gets very big, very quickly... I'm working on a project now that is loading about 19 jQuery plugins in addition to jQuery, as well as a handful of both bootstrap and jQuery-UI extensions, and the payload of a relatively simple page is coming in over 2MB (even if most of that caches, it's really big for a first hit).
People tend to start with a kitchen sink, then add not only the rest of the kitchen, but the barn as well without a thought or consideration to the final result, and the payload that goes with it.
However, let's be clear here: most people who complain about the size of jQuery are doing so without any basis whatsoever. And even if people are measuring, they may not be measuring the right things. If not using jQuery causes you to reduce your Ajax usage, and reload entire pages as a result instead of only reloading the content, the end result is a slower site.
Remember size isn't as much of an issue when it's less than 100kb (though 3G or less networks that will still be painful). The biggest issue is yet another file for the browser to fetch. Synchronously or asynchronously the browser will still open another connection to the server to grab the file which results in further latency before your application really starts up.
There's no reason you can't concatenate jQuery with the rest of your JS.
True and most applications should really do this. In reality I've seen far too many production system still including sometimes over 50+ files.
Less javascript means less cycles burned executing boilerplate framework factories means faster page loading means longer battery life means you can keep that two year old phone that's not quite so fast instead of throwing it in the trash.
jQuery causes global warming. (tongue-in-cheek of course, but not entirely)
As much as I'd love to stop keeping track of IE8 bugs, for a lot of sites this isn't possible. And, IMHO, this cavalier attitude is what causes many websites now to work "best" (read: only) in Chrome. It's true that a lot of sites (I'm thinking Webapps) don't need jQuery at all, and a lot of sites can get away with just using Sizzle, but 28kB is a small price to pay for the utility functions, cleaner AJAX API, event binding registry, etc. If you don't need them, by all means don't use it.
I think that's a good thing.
In 2015 most browsers are in much better shape than they were in, say, 2007. A lot of people are mostly targeting users who use up-to-date, standards compliant browsers. They are also often targeting people who use mobiles, which are (for a couple of reasons) much more sensitive to poor JS performance than desktops, and also see a more tangible benefit from small page sizes.
Another advantage to jQuery was making complex JS operations very simple. Modern JavaScript has actually made life much easier[1], meaning that it's often only a little more work to use vanilla Javascript.
Though I think most the people moving away from jQuery are doing it because the browsers have become more consistent in how they run JS.