7:53 You can always simulate slow connections via Web Console > Network > throttling > Slow3G

@pearl911

Жыл бұрын

I was wondering why he didn't do that also because he's already used it in videos such as kzread.info/dash/bejne/jIqpyZhul7qTlsY.html

@Flash136

Жыл бұрын

@@pearl911 I'd say using a wait function makes the wait time more deterministic. And you can change the wait time to however long you want.

@lleytonmorris6305

Жыл бұрын

Thought the exact same thing. Best part IMO of the network tab is the ability to set a custom TTFB which is a very real and practical scenario to test.

@victormog

Жыл бұрын

Kyle showed an example of a useful Promise 😉

@Pete133

Жыл бұрын

That is pretty useful, but for what it's worth doing this particular task with dev tools throttling would have required waiting much longer for react itself to download than for the component to download... the way he did it was actually a lot better for the demonstration.

Asynchronous imports aren't just a cheat code to making your app faster. You should only use it if there are portions of the app that are not needed until the user initiates some process. For example if some component is hidden until the user clicks a button, then you could asynchronously import that component.

@gabrielemarino1360

Жыл бұрын

There is also a prefetch variable for webpack which download that resource when the engine is idling. It is not quite the same situation but i wanted to point that out

@mithunkumar-vm5iw

Жыл бұрын

Like lazy loading in angular?

@jackykwan6534

Жыл бұрын

@@gabrielemarino1360 this should be better, let the engine do the job for u

@Cotita

Жыл бұрын

And why would you not load portions of the app that are not needed yet? Why not just load them from the beginning? To make the app faster, genius.

@theyreMineralsMarie

Жыл бұрын

@@Cotita yes but my point was that it's important to know how and why to use this feature. Just throwing around async imports everywhere isn't necessarily going to improve anything.

Please bring more videos related to performance improvement, aria, testing related, logging, debugging issues, improving css loading time etc

@techjourney2754

Жыл бұрын

this guy is a busy guy bro, probably has a full time dev job, he runs his own business and he makes videos, 😂, work ethic i aspire to have

At 07:52 To depict Loading... you don't need to add wait. You can simply open up your console, Go into Network Tab. In the bottom layer, you'll see "No throttling", click that and change it to "Slow 3G" and there you go. You can actually see how your fallback will work when there is a delay in your network.

The quality of these vids has gone way up over the years man! Well spoken.

That's the best thing ever. I didn't even think that this could be a thing in React at all. Thanks for making this video! 💕

I always wait for your content about React JS. Thank you for the knowledge 🙏

Kyle, this is a great video. However, I think there are a few additions that would've made it better: 1) In addition to showing files being downloaded piece by piece, demonstrating this using network tab in the dev console would've also be a great way to show people how to also make the most out of the dev console by debugging network latency, Showing them that you're downloading the entire client app in one go versus downloading it bit by bit as the user uses the site over time. 2) Another dev console trick would've been to demo the way emulation of 4g internet works by using the throttling feature in the network tab as well. That wait function is pretty cool but these tools were built for developers in mind. 3) Finally, if you added a build script and built the app, showing people how the bundle was created as just one large js file before lazy loading but after adding lazy loading, it bundles itself into multiple smaller bundles.

@lima91rs

Жыл бұрын

"multiple smaller bundles" - a.k.a. chunks

@user-gi6yc5nu6g

Жыл бұрын

3 was really missing! thanks :)

@xbsidesx

Жыл бұрын

Nice suggestions indeed!

@filipniklas

Жыл бұрын

Great suggestions!

Great video clear explanation and example as usual ⭐

I watched this lesson 2 month ago, but always try to revise your videos. Thanks!

Always things i've never heard about before. Great stuff!

I loved this video. I understood way better the concept of code splitting. I can now apply this knowledge, Thank you very much Kile😁

Great video Mr. Simplified. Thank you!

Man, you are a true hero! Thank you very very much for the amazing content!

Great video as always! Keep it up, you're an essential instructor in the Javascript ecosystem 😎

Nicely done friend. I learn so much from your videos. Thank you.

I was waiting for your new video, hanging around the playlist section .

Great as always. Thank you, Kyle!

Simply WOW , this may super useful when we working on complex applications

Learn so many stuff in just 15 mins, thanks a lot.

I think it's important to note that the helper function at 15:06 will not work in production builds depending on the build tool you're using because the transpiler can't guess ahead of time what you're going to import through that function (Vite even warns you about that). I tested it with Vite + TypeScript (no SWR) and while it does work fine in dev mode, it will not work in production mode. The transpiler doesn't create the imported JS files in the destination directory and the app will try to dynamically import "/assets/components/Something(.js/.ts)" which obviously doesn't exist. Unfortunately, I don't think there's a workaround for this in JS alone, but there could be build plugins for it.

@lijason3766

Жыл бұрын

which means you are expected to leave your code un-bundled as if in dev mode if you are going to use this dynamic import cheat.

@nicholasdickrell5118

Жыл бұрын

100% this answer. When you run a large app, the last thing you want is failed to load dynamically imported module clogging up your logging and getting calls from your Bridge.

@IAmLesleh

Жыл бұрын

Just pass the import("whatever.js") to the helper function instead of just the filename, problem solved.

@botchusaimanoj4597

18 күн бұрын

Thank you so much. i wasted so much time not knowing this.

@botchusaimanoj4597

18 күн бұрын

This worked for me function lazyLoad(fileName, isNamed) { return lazy(() => { const promise = import(`./${fileName}`); if (isNamed) { return promise.then(module => ({ default: module[fileName] })); } return promise; }); }

thankyou for this useful information really appreciate you for this.

In the lazyLoad function, you don’t really need an else statement since you’re returning from the if. Without an else that would be an else regardless. I know some people prefer verbosity, but that’s actually confusing for some. Great video regardless, you’re a very good communicator!

Great video clear explanation and example as usual

Explained perfectly. Thank you

Nice, ive learn something new. Good job

This is really helpful , thank you!

Good God, finally a valid explanation of this topic. Thanx a lot sir.

Very useful tutorial! Thanks

Informative concept. Thanks

Great Explanation Bro

Have learned a lot from you bro, ❤️ from Bangladesh

Very useful and clear!

Great video. You can use both default and named export at the same time, so technically you can use default for the main component that needs to be loaded in the route. I always use both!

@tan2cang93

Жыл бұрын

indeed, I always use the way like that,

@likatest7718

8 ай бұрын

If i use default should i adding second paraneter in lazyload function?

Amazing video, thanks!!

I was struggling with permission based access for the user in my app. Things weren't working very well. Now, I think things will be fine when I use the useTransition hook. Great!

Another awesome video. Tks.

Great video, thank you. Splitting stuff into more bits is not just making app faster, but its also good for separation of concerns.

Thanks for this video. Design is very human, easy to use) Thanks ❤

as always, great video 👍

tnx for your tipe's bro

Great video. Thank you.

You are incredible thx for the video ❤

Great content! 👏

I don't know why but somehow I can understand your video with my not really good English. Thank you so much mate !😁

Nice work! 👍🏼

You forgot to add this is only suitable for really huge components. If you "lazyload" all the things you are actually slowing down your application at runtime to gain faster load at the start. This way your page/app will become laggy on slower connection speeds and this is not advised in production. It has terrible impact on look&feel. You want your apps to be responsive and snappy even if it loads 0.2s slower at the beginning, you will probably never reload this page (SPA) and most of the things will get cached.

That's interesting. Qwik is doing something like this. It listens to the global window object then brings in the data when there are actions. It could certainly help bring code down on first load.

So useful! My react app was taking long minutes to be loaded it weights something around 700MB, and my computer is a little weak, i thought it could be this, cause, until now, i didn't even know this was possible.

Thats some real advanced knowledge

Excellent, thanks

Thank you, this is a great feature of React that I wasn't aware of. But when using TypeScript, passing the path to the component into your lazyLoad function doesn't work. But if I changed the lazyLoad function to accept a Promise, then pass into it the import('...') and then the namedExport, it works fine.

This was really helpful

this video... golden!!!!!!

Great tutorial

Incredible 👏

Thanks, Kyle. Instead of writing wait promise and more codes (because this is web dev simplified), it was better to use fast or slow 3G throttling from network tab.

Hi Kyle, TY for the content, very useful videos I usually use Lazy loading and suspense, but something that I didn't fully understand from your video was: What is the difference between using the fallback prop in VS useTransition ?

Very great video

Excellent!

Huge love from India Kyle :) ❤️

Very helpful

Thanks for an other amazing video, it would be great if you also add link to in description to related blog on your website. thanks

I have changed many files from named export to default export in order to apply lazy loading. Then, I found a lib react-lazily which help me do the job. Anyways, thank for sharing the lazyLoading function. cool!

excellent stuff

Code Splitting is Splitting bundle into multiple parts that can be downloaded over time ('lazy loading") . That help us to easy optomize our application , fix real performance issues...

useful. thanks

very very useful

great video,

By the way, you can also simulate slow internet using your chrome browser by setting the network speed in the developer tools.

Thanks for sharing your knowledge ❤ Please make videos abour Angular alsoo... Please 😢

the way you explain >>>>

great video

considering its pros, should we always use it? there wasn’t much discussion about its disadvantages so i’m not sure if it’s bad to always split code like that

Thanks from Kerala

Thank you

Thanks a million

Hm.. for some reason I don't see all the folders as you see on your screen, I only get static folder under localhost and inside the static folder, there's only two folders that is `js` and `media` is there a different setting I need to enable to see folders such as 'src' folder?

Great. I use the lazy Suspense in my router too. But what about error baoundary? How and where to use it?

Thanks!

@WebDevSimplified

Жыл бұрын

You're welcome!

The best!

Kyle you have a problem your audio output on your videos. Use +0db or not use lower then -2db and alsoe there is audio balancer tools on video editing tools if you worried about audio changes. I just have to turn up the volume almost all the way for your videos and I can't turn anything else on, because any other audio output, video music etc. it's terribly loud.

very useful

They are great strategy for specific need, however if u required to do so much of the code splitting on so many components, u might as well go for micro front-end, solve it entirely instead of pieces here and there

You are awesome. Can you make a small code for login and register pages using fetch, that shows conditional component after login/before login? if you have already made such a video, can you provide a link?

What's the best way to manage having a significant number of elements? I'm building a react application for myself to do engine ecm editing. The binary is 3.4mb, the json for the parameters is 8mb and there are 17,600 parameters. About 2000 of those are x, xy and xyz tables. Total rendered component count is probably north of 25,000.

you can also throttle your network from the chrome dev tools

I love you thanks

I used this in my proj and had some issues, like sometime some components not working properly or styling is not there . I could not know what's the problem because it's some time just work fine . So i ended up returning to normal import.

Nice video

Have you ever tried webpack's module federation plugin ?

Thats basically a Resumable Hydration (Up to 4:25), that is what Qwik is doing under the hood

Wow... Thanks a bunch. This will help a lot. There's a project that I'm currently working on; after building it up... One of the main js files is about 24mb... How can I optimise it more... It takes a lot of data and time to load from the web server.

Hey everyone! I found that when you use the `lazyLoad()` function that Kyle created, vite cannot analyze the dynamic path for the import and therefore will not be able to properly build the js and file paths for these components when you run the build command. To get around this I found that you can pass the whole import function into the custom function like this `lazyLoad(import('./components/AdminData.jsx'), 'AdminData')` and use that instead of assigning the promise variable. This keeps the import path static so vite can work with it during build time. `export const lazyLoad = (importCall, namedExport) => { return lazy(() => { if (namedExport == null) return importCall; return importCall.then(module => ({ default: module[namedExport] })); }); }`

Do i need to make imports in all files lazy loading? (i.e. passing into the lazy component as a callback) or just import lazily imports of App.js file? Can you please elaborate?

Could you make some videos about node.js eventemmiters, the resources for them have always sucked

That's why we Use Nextjs For production ready app.

Is the lazy method in your routing example used by the Next.js team when using the component?

so if I lazy load context subscribers, it won't re-render all the context subscribers, when the context update?

What if I want to lazily load home and store together and about separately ? During build phase, home, store and about is broken down into different js file. Is there a way, we can consolidate home and store together in a single js file and about in different js file?