[com2kid]

Svelte is so insanely lightweight, I think it is a great counter argument to a lot of the SPA hate.

And honestly, most of the weight in modern websites comes from analytics and tracking tools. I've made insanely performant SPAs that work well on low budget hardware. My personal phone is 5 years old, if code I write doesn't perform flawlessly on it I'm not going to ship it to customers! Heck my personal dev laptop is a 4+ year old $999 Costco special.

Well made React sites can run just fine on devices like that, and Svelte runs even better.

Also SPAs scale better, I remember the days of website backends being slow, with page loads taking forever, massive amounts of HTML being generated server side using slow scripting languages.

Sending a JSON blob of some fields to the browser and having the browser update some nodes makes a lot more sense than the old school way of reloading the entire bloody page to change a couple fields.

[pweissbrod]

By choosing an SPA. You must choose a dedicated static site hosting which is separate from your web application. You may already have this but you may not. In most cases you must choose a framework for routing. Also a framework for state management. You also dedicate to duplicating validation and security trimming logic both on the client side and the server side. More often than not you will find yourself including hundreds of NPM packages as dependencies which you must continually update and maintain. Also the requirement for unit testing on the front end is common. Which brings in the need for things like jest and enzyme. This complexity inevitably trickles into your build and deploy processes. Perhaps in larger teams this is a burden you can absorb. In smaller teams however you start to see division of responsibilities. One person only knows front end but not back end and vice versa. Common knowledge of the application as a whole can become fragmented. Perhaps the day comes where you want to take a partial of a user interface posted in a peripheral application and place it inside your web page. Because you have a virtual DOM this is now a security risk. You must build a component which duplicates the user interface which already exists. If the user interface needs to be shared among many applications you must build a commons code base to host your components. You start shouldering the burden of maintaining component libraries instead of just HTML and CSS. Again this is all very general and hypothetical but it feels worth pointing out some of the common implications that simply choosing an SPA can have in the longer run.

Plus this is not an all or nothing sort of choice. For decades we have used Ajax to perform partial updates on a web page. Consider alternatives like HTMX as a comparison.

[shortcake27]

> By choosing an SPA. You must choose a dedicated static site hosting which is separate from your web application.

No you don’t.

> In most cases you must choose a framework for routing. Also a framework for state management.

I don’t understand this argument. React gives the developer this freedom by design. If you want a framework that has all of these decisions made for you, they exist.

> You also dedicate to duplicating validation and security trimming logic both on the client side and the server side.

I’ve been validating on the frontend for 15 years, long before I worked on an SPA. It has never been necessary but it provides a better experience. If you don’t like this, you can still let the server do all the validation. There is nothing about an SPA that enforces client-side validation. And you’re wasting your time if you’re doing security filtering on the the frontend.

> Also the requirement for unit testing on the front end is common. Which brings in the need for things like jest and enzyme.

“Grr this paradigm allows me to test my code, I hate it!”. Seriously, we’re now able to write unit tests which were previously impossible. How is this a bad thing? Also Enzyme hasn’t worked since React 17, I now use RTL which asserts user behaviour - super nice.

> Because you have a virtual DOM this is now a security risk.

What?

> You must build a component which duplicates the user interface which already exists.

How is this any different to a non-SPA? Regardless of technology you can’t just arbitrarily lift interfaces from unrelated applications and inject them into your application without a bit of work.

> If the user interface needs to be shared among many applications you must build a commons code base to host your components.

Again, how is this any different from a non-SPA? You UI isn’t going to magically share itself between applications just because you don’t have an SPA.

I’ve worked on all types of applications and I don’t think SPAs should be the defacto approach, but I really feel you’re clutching at straws with all of your arguments.

[pweissbrod]

Recently we went through an exercise where we built a to-do simple app using react and rewrote it using HTMX.

The functionality was identical between the two apps. The amount of tooling code and duplicative logic was massively higher because of SPA and all the fundamental things it demands.

Now if you really need an SPA for your requirements because you have an intrinsically complex front end and you've mastered the hoops to jump through good for you! There's nothing wrong with that. But there is something seriously wrong with building the same user interfaces we've needed for decades but the time code and complexity drastically increasing for no justifiable reason.

[com2kid]

> Recently we went through an exercise where we built a to-do simple app using react and rewrote it using HTMX.

React is boilerplate madness.

Do the same in Svelte.

I did a form heavy app in Svelte, literally took 1/5th the time it would have taken in React.

SPA fundamentally means that instead of refreshing the page, just the data needed to update what is on screen is sent down to the user.

Ideally, "send data about products on next page of search results" is less than "send all HTML needed to render the next page of search results."

Also the backend ends up simpler, instead of trying to template strings together, the code can just worry about fetching and returning needed data.

I am legit confused why people think generating HTML in some other language (Python, Ruby, etc) is a good idea.

Keep HTML in the browser (easier to develop and debug!) and keep backend business logic someplace else.

[pweissbrod]

When you have a team with predominantly back-end knowledge expertise using a templating language they are familiar with plays to their strengths. MVC applications were written for over a decade. Perhaps it is a subjective thing because I don't see any logical difficulty in a web page that exchanges partials instead of JSON. I was programming that way for over 10 years.

Svelte really sounds compelling from what you're telling me. I'll check it out. But unless it is a drastic simplification it brings with it the fundamentals of effectively writing a thick client in JavaScript or TypeScript and all the things that come with it. React and angular have left a very bad taste in my mouth. The time and code cost for building basic user interfaces should go down not up. We should be spending less time talking about how to do something and more time talking about what to do

[com2kid]

> But unless it is a drastic simplification

95% of what you write in Svelte is just HTML. You then databind whatever you need using an obscenely lightweight syntax.

Svelte also has an optional SRS framework called SvelteKit that auto creates REST endpoints for you, and auto binds stuff to them, but all that is optional and not needed.

My issue with backend HTML templates is that essentially you always have to know HTML + CSS anyway because browsers suck and they still have differences, so I always end up spending a ton of time fixing CSS and HTML issues. Having to fix HTML issues by way of the backend that then generates HTML feels like an unneeded abstraction.

Instead I can just... write HTML and CSS.

[KronisLV]

I won't touch upon most of the points (because those are highly situational), but I'll offer my opinion on the following:

>> By choosing an SPA. You must choose a dedicated static site hosting which is separate from your web application.

> No you don’t.

It is true that you typically don't have to do that: you can just package the built assets of your SPA into whatever serves the rest of it, provided that you don't mind a monolithic deployment. I've seen many applications like that, both in Java (Spring Boot), PHP (Laravel), Ruby (on Rails) and so on, it generally works okay.

However, I'll also say that it's pretty great to have two separate folders in your project: "back-end" and "front-end" (or separate repos altogether) and to be able to open those in different IDEs, as well as to be able to deploy them separately, especially if you want to create a new front end (say, migrating over from OLD_TECH to NEW_TECH while maintaining the old one in parallel) or something like that. Otherwise you have to mess around with excluded folders for your IDEs, or if you open everything in a single one everything kind of mushes together which can be annoying, and your build also cannot be parallelized as nicely, unless you separate the back end and front end compile steps from the package step, where you shove everything together.

Personally, having a container (or a different type of package) with Nginx/Apache/Caddy/... with all of the static assets and a separate one with the back end API feels like a really nice approach to me. In addition, your back end framework doesn't need a whole bunch of configuration to successfully serve the static assets and your back end access logs won't be as full of boring stuff. If you want to throw your SPA assets into an S3 bucket, or use one of the CDNs you can find online, that's fine, too. Whatever feels comfortable and manageable.

Now, whether SPA is a good fit for what you're trying to build in the first place, that's another story. Personally, I like the simplicity of server side rendering, but also like the self-contained nature and tooling/architectures behind SPAs (though personally I'm more of a Vue + Pinia person, than a React/Angular user, though they're passable too).

[jsyolo]

What backend tech do you like to pair HTMX with?

[pweissbrod]

That's the thing. It doesn't really matter. It's sort of like asking what backend tech you pair with jQuery

[AtlasBarfed]

I wish there was a "works for Pentium III" label that would help indicate that the app's usability hits necessary minimums on a 1Ghz Pentium III computer. IMO that would be a good optimization floor for avoiding the hidden monstrosity of electron apps and that type of stuff.

If your McCrud app can't be responsive on a baseline 1Ghz PIII with 1GB of RAM, then there needs to be some sort of shame pushback. Moore's law is effectively coming to a close, there will need to be more optimization in the future.

[mrtranscendence]

Why Pentium III? That's nearly 25 years old. You couldn't run Windows 10 on such a processor, let alone a modern browser, and a $200 mobile phone would beat it in benchmarks. Surely you can have a higher floor than that.

[AtlasBarfed]

The Pentium III was the around a half a gigahertz, and we were starting to get into multi-hundreds of gigabytes.

... that sounds small compared to today's specs, but IMO this is when PCs had plenty of horsepower to run "real" operating systems (32-bit preemptive multitasking), "real" browsers, 3D gaming was into it's fifth year or so, etc.

So this wouldn't be a badge where you say "wow we fit it into this impossibly limited device". The dirty secret of the PC business is that this hardware spec is more than enough for practically all productivity and browsing (and video with hardware acceleration). Now, high polygon high res high antialiased games... but that has actual hardware horsepower needs you can quantify.

The amount of wasted resources from the year 2000 to now is stupefying. Intel and AMD love it! DRAM makers love it! But as an industry we have squandered the last two decades (and the last two decades of CPU improvement), right as gigahertz scaling disappeared, Moore's law is probably going to collapse under its economic weight, Amdahl's law says parallelism won't save us forever.

So if I look at some software and wonder why this relatively straightforward app is hogging along on a PC that is effectively 10-50x faster than a Pentium III 500Mhz (8x-10x in clock speed, then massive improvements to cache, branch prediction, multiple ALUs, speculative execution)... something is wrong.

[com2kid]

Google Maps ran like a dream on Pentium M systems back in 2005. Gmail was also smooth as butter.

Pentium M was a derivative of the Pentium III design.

Ignoring high resolution image assets, there is no reason a website shouldn't degrade and be able run on any machine faster than 300mhz.

[toastal]

Works on a KaiOS feature phone support would be a relevant metric today with similar goals that you mention. They explicitly state in their docs that React will be too heavy for your app.

[marcosdumay]

Is there some VM that allows limiting the CPU to a performance similar to a P4? (A PIII is way too bad for my tastes.)

I imagine Linux would have a bad time running in it.

[com2kid]

Pretty sure PIII's beat P4s at a lot of benchmarks. :-D Thus why AMD is around today.

[marcosdumay]

Well, I was using AMD at the time.

AFAIK, the P4 faced badly on jump-happy code, but this was not common enough to be a problem on the real world when compared to a PIII. It was also a power hog, that could barely outrun a snail if you didn't have proper thermal management, but that also doesn't means the processor is slow.

[com2kid]

I should have specified perf / watt. Pentium M's came and cleaned up compared to P4s, there was a fair bit of time there when, excluding massive power hungry desktop monsters, a beefy laptop with a Pentium M could easily beat an average desktop with a P4.

And IIRC pipeline stalls on the P4 hurt, badly.

Oh and RAMBUS, I had forgotten about RAMBUS. That also hindered the platform.