10 ms·

Single Page Application Is Not a Silver Bullet

196 points by bloomca 9y ago

buchanaf 9y ago
Not the most compelling list of pros/cons that I have ever seen. In terms of raw performance for content sites, I found hybrid implementations like Gatsby.js to beat most things. Most of the cons of SPAs can be significantly diminished with SSR, proper chunking, and a variety of other modern techniques -- it just gets complicated in a hurry.
- ryanworl 9y ago
  For anyone reading this thread and thinking about server side rendering their single page app: do not go down that route unless you’re willing to also implement proper chunking! If you SSR your pages, but still need to load a giant bundle, you will get the worst of both worlds: a page that looks ready, but makes your users extremely frustrated because they can’t interact because your app isn’t booted yet.
- piranha 9y ago
  What's chunking in this context?
  - ryanworl 9y ago
    Breaking down your JavaScript bundles into smaller files that contain the code necessary for the route you’re actually going to be viewing once the page is loaded. For other routes, you fetch the necessary code on-demand. This lessens the CPU power and bandwidth needed to initially load the page.
baddox 9y ago
> broken “open in a new tab” behaviour – people like to handle links in onClick handler, and browser can’t recognize it as a link (even if the majority of the links are valid, sooner or later you’ll encounter a non-link “link”) This one annoys me the most, but I will say an analogous problem is fairly common on non-SPA web sites, where reloading a URL doesn’t work as expected.
- wavefunction 9y ago
  That's usually just a lack of basic engineering practices common to well-implemented SPAs. All requests below the SPA's root should be forwarded to the SPA root, which appropriately then routes the request to the proper views and controllers. Proper usage of resource IDs in these URLs allows a newly initialized application model to populate and serve the appropriate content for the appropriate views.
  - userbinator 9y ago
    The point is that browsers already have built-in code to interact with links and such in a predictable and straightforward manner, and your suggestion that "a lack of basic engineering practices", implying all SPAs need to reimplement that functionality, shows just how absurd the situation is.
    - wavefunction 9y ago
      The fundamental difference between a SPA and traditional website is that the routing and compositing of views is generally handled by the client rather than the server. It doesn't make sense to call something that doesn't respect that design a SPA. A poorly implemented SPA is what I would call that.
      - wavefunction 9y ago
        Zero contrary posts pointing out where I'm possibly wrong but them vote-brigading remains. Hackers News '18, folks.
    - bhldr 9y ago
      Most SPA's don't, because most frameworks have some built-in functionality for this.
    - manigandham 9y ago
      There's nothing to reimplement. Browsers navigate based on URLs, so if the URL for a page in an SPA isn't enough to load the full state on a fresh pageview, then it won't work. So it's absolutely about proper engineering to make sure pages have working direct URLs rather than just relying on other navigation while the app is already open.
burlesona 9y ago
One of the ways that I prefer to judge a JavaScript framework is (1) what is the minimum payload to use it, and (2) how nicely does it play with a hybrid app? In practice I’ve found VueJS does pretty well in this regard. Rather than build a full SPA I can sprinkle a few components here and there on pages that are highly interactive. The rest of the mostly static screens on my app are perfectly happy to be rendered from the server. It can be hard to strike the right balance between developer friendliness (ie maintainability and extensibility) versus user experience (ie speed and backwards compatibility) these days, but as always it’s important work to deliver the best user experience we can, and I agree with the author that SPA are not always the right choice in this regard.
- unclebucknasty 9y ago
  >Rather than build a full SPA I can sprinkle a few components here and there on pages that are highly interactive In practice, I've found "hybrid" apps hard to pull-off. In my experience, the question becomes, where do you draw the line? Take the simple/common case of presenting a list view. From the list, you want to allow the user to click to view details, which you then present dynamically--maybe in an overlay. It's a great user-experience. Everything pops, the user can easily return to the list view without a full page-load, etc. But, you now have a details view that is not reachable directly via its own URL. So, you use the framework's routing capability to assign one. Now, things are getting weird, because you're routing a dynamic view on top of a server-rendered one. You'll likely end up finding that you'll have to route the server-view as well for general navigability. And, you also have to account for people hitting the details URL directly (i.e. render the proper underlying server view, then let the client route to the dynamic URL). Not to mention the back-button. All manageable, of course. But, it gets messy to maintain such a hybrid approach. By the time you've integrated the routing, etc. the question becomes why hybrid? Why not full SPA? If your app is super-simple wherein you're just doing the tiniest bits of dynamic stuff and you don't need things like first class URLs, navigability among dynamic content, etc. then, yeah, maybe. But, that's not really a hybrid-SPA solution because there's no SPA there. In fact, I'm not sure there is a such thing as "hybrid-SPA". By definition, seems it's either a SPA or it's not.
  - 9y ago
adamnemecek 9y ago
One thing that doesn’t get mentioned is that writing an SPA feels more like programming. Writing jquery feels like idk...not quite like programming.
- kylnew 9y ago
  It’s a lot more like writing a native mobile app, that’s for sure. You manage data and state with a much more long-term mindset. A bad line of JS is equivalent to a crash if it halts the whole SPA from working and requires a refresh.
- mythrwy 9y ago
  I'd about say the opposite. Organizing all your jQuery into meaningful classes and keeping the whole thing organized and orchestrated is very much the essence of programming. It's a rare skill (as a trip through many large jQuery code bases reveals). Filling in some templates causing magic to happen behind the scenes on the other hand, not so much. That being said, 1) are we interested in feeling like programmers or in pumping product? 2) if "pumping" is the answer, best tools depends on what is being done. All in favor or SPAs (when needed), but no, they aren't cooler than jQuery and are often big fat pigs that just shouldn't be used in that situation.
  - unclebucknasty 9y ago
    >I'd about say the opposite. >Organizing...into meaningful classes and keeping the whole thing...orchestrated is very much the essence of programming >Filling in some templates causing magic to happen behind the scenes on the other hand, not so much. I'd agree and add that the different perspectives might be in large part due to the shift in programming away from procedural/code to declarative over the last decade or so. That is, if you started in coding over the last ten--and especially five years--you're much more likely to think of programming as declarative as much as code-oriented. And, the shift towards frameworks is probably the biggest driver of the declarative trend itself.
    - mythrwy 9y ago
seawlf 9y ago
I've worked on a number of SPA's over the years and I always run into the problem of getting my team to give a shit about performance. "We're not Google," they protest. Frankly for a lot of people it's the trade-off of slow client performance for development velocity. It's much easier to just throw on another state for new functionality than it is to consider what parts of the page can be static and how they can be rendered.
- andybak 9y ago
  Surely if you can't produce an SPA with equivalent or better performance than a more traditional architecture then - don't build an SPA. Or even better use a simpler solution that gives me 80% of the benefits of an SPA: Turbolinks, PJAX, intercooler.js or even a light sprinkling of good old AJAX. Does anyone remember "progressive enhancement"?
  - tacone 9y ago
    Perhaps the most simple and trasparent solution to seamless navigation: http://instantclick.io/ http://instantclick.io/ As long as your backend is fast enough, it feels like navigating a SPA.
- thehardsphere 9y ago
  See, "we're not Google" should actually mean that you care about performance more. Google can throw millions of dollars worth of infrastructure into making an app go marginally faster. Whereas, all you have is brainpower before you deploy or ship. And it doesn't take that much more brainpower to get big increases in client performance when you're starting from not-optimized-at-all. The marginal payoff is larger and the marginal costs are much smaller.
jconley 9y ago
Many of these pitfalls can be avoided with intelligent server side rendering, which includes the router on the server, so no using client-only “#” URLs. But, that adds another significant layer of complexity to application development.
userbinator 9y ago
Half-expecting this article to itself be SPA, and was pleasantly surprised that it isn't. I agree completely with the author; there's some things (games and such come to mind) which certainly deserve to be SPAs, but the majority of the time it's a horrific waste for every single visitor to have to process MBs of data just to display a few KB of text and hundreds of KB of images (at most). Why? Just so developers can show off that feeling of how awesome they are for using some incredibly complex framework. That, and the ridiculous rate of churn, are probably what most irks me the most about the whole web development community (and why sites like HN appeal to me so much.) I'm not sure what's responsible for this "love of bloat", but IMHO we should be teaching developers how to do more with less, and not the complete opposite as seemingly happening today.
- Can_Not 9y ago
  > Why? Just so developers can show off that feeling of how awesome they are for using some incredibly complex framework. ... I'm not sure what's responsible for this "love of bloat", but IMHO we should be teaching developers how to do more with less, and not the complete opposite as seemingly happening today. I think you're misplacing the cause into developers. Developer's want to use the SPA framework because certain magnitudes of "application like UI" become maintainence nightmares for teams who stick with jQuery or use youmightnotneedjQuery. The reason they end up bloated or with random framework-supported elements broken (back button, etc.) is from what I call MVP culture. AIM and IRC were perfectly fine in the early 2000s, but instead of upgrading them for 2010+ they were abandoned or stripmined of value (Skype). Now we have slack, discord, flock etc.. releasing MVPs. Except apparently, they are perpetual MVPs. Many industries are encountering this. Developers at large are not permitted to rewrite in native languages, optimize any non-blocking performance issue, fix bugs that don't affect the bottom line. Everyone's trying to disrupt an industry so they can vendor lock in high profit rents. When we finish switching from typescript to reasonML and decide to switch from reasonML to Nim/kotlin-native, MVP culture will still be there to tell developers not to fix the broken back button.
andrenotgiant 9y ago
I always thought the decision was: - Content site = NOT single-page-app - Application = single-page-app Maybe there's more of a gray area between content sites and applications these days, but I think it's still pretty obvious: If most of the user's time is spent reading content, it's a content site.
- thehardsphere 9y ago
  That's a good starting point. I'd drill down even further and ask "what does the user do with the application?" If the user needs to look at multiple screens at a time (e.g. like a mail client or something of similar complexity), then they're a candidate for an SPA. If the user does not need to do that, the app is probably simple enough to not be an SPA.
- motoprog 9y ago
  I work in ecommerce and I feel it’s somewhere in between. We need to build for seo optimizations for the category/product experiences yet there is a lot of application like intersections, especially on the category filtering and the product sku selections. Quickshops, In store pickup modals, user specific recommendations trays, add and edit reviews et all. Different caching for server render at the edge vs personalized components adds another layer. Being able to serve with a shared routing scheme both client side (for improved performance) and server side for faster initial page load and seo on non-Google crawlers is a tough problem. Especially when you add in client hydration of the redux store. That parse time is a real killer on mobile. You add in service workers and prefetching and the complexity ratchets up further. The other issue we deal with is marketing pixels and trackers. But that’s another story. There is a ton of complexity in building a highly functioning ecommerce site.
  - ccachor 9y ago
    Is it really worth the trade-off? I remember eCommerce sites trying to do similar levels of interactivity with Flash too. I just think, for a catalog site, it seems like you're trying to swim upstream. Especially on mobile.
- 9y ago
thehardsphere 9y ago
The problem with SPAs in the sort of cases that the author is talking about is that people don't think clearly about what requirements they are satisfying when writing a new one. If your app actually needs to switch between various screens without a refresh so your users can most efficiently get their work done, then yes, by all means, make an SPA. That requires knowing clearly who your users are, what they want to do, and what constraints they are under (e.g. if they all work on desktops with good internet access, maybe it doesn't matter that your app is bloated and slow on mobile). I think most people don't do that thinking step first. They want to play with the new shiny, either as a sort of fun or so they can add it to their resume. This I think is made worse by the unparalleled decadence in which the modern, first-world developer now lives. It is absolutely excessive to have to download 2.6 MB just to show a blog or some simple textual information, but thanks to broadband everywhere and terabyte hard drives, nobody under the age of 30 who isn't working in embedded systems thinks about this anymore.
tzakrajs 9y ago
"Stop writing only SPAs" is advice in the same way as "stop making only left-hand turns". This article stops short of convincing me to stop biasing towards SPAs because it appears only to reiterate known challenges about SPAs and calls out bad practices (tons of unused javascript libraries). SPA frameworks are pretty damned good and they really can and ought to be used wherever you feel the need because some SPA frameworks are very quick to get started with and can be customized to significantly reduce bloat.
JohnnyCrazy 9y ago
TBH most of the cons stated in this article are just because of bad programming, not because it's a SPA > broken “back” button (sometimes it works properly, but in general people don’t trust it) If your UX is good, the user will notice data is refreshed when going back. All current top tier SPA Frameworks have support for correct HTML5 routing. > broken “open in a new tab” behaviour – people like to handle links in onClick handler, and browser can’t recognize it as a link (even if the majority of the links are valid, sooner or later you’ll encounter a non-link “link”) Again, most up-to-date frameworks have a fallback by adding a normal href so you can still CTRL-Click it. > sometimes broken “refresh” button – after refreshing you end up in a different UI (usually slightly, but still different) I don't see a real disadvantage here, since you can simply store your state by manipulating the URL or even localstorage. So you even have the possibility to not store your state...But again, application design, not SPA I do agree with TTI (at least on the first load) and bad performance on low end devices.
- jordache 9y ago
  No. Because it is an SPA, it means there is more work to restore the default behavior of the back button. That's the way he should have articulated his point. You also mention HTML5 routing.. Ok now you have to configure your web server to properly parse the URL and understand what it's conveying.
  - Can_Not 9y ago
    And all of that work is already done for you in all modern major SPA frameworks.
    - jordache 9y ago
      Server side too? Client side routing? Have you seen the huge chapter dedicated to routing for angular? You make it sound like it's no work
      - Can_Not 9y ago
geraldbauer 9y ago
Great to see the article posted on a "classic" (static) website built w/ jekyll. Find more open source (ready-to-fork) themes @ https://drjekyllthemes.github.io https://drjekyllthemes.github.io Build your own "classic" websites / blogs :-).
vincentriemer 9y ago
As an avid developer of SPAs (currently working on one for my own blog frontend) I'd say a lot if this stems from people being convinced SPAs 1) provide a faster development cycle, 2) they believe that they've offloaded all need for optimization on the framework they use and 3) "serious" development teams build SPAs. Anecdotally I find SPAs, while I'm more comfortable developing them, will take longer to build. You need to pay more attention to the quirks the author mentions and you need to spend more time explicitly optimizing your code. I like this paradigm because if there is inconsistent logic, poor performance, or other issues, it's my fault and I have the opportunity to fix it. As a counter example to the ones mentioned in the above article, around 2 years ago I build a drum machine webapp entirely in JavaScript/React (https://io808.com https://io808.com). This has ~17 JS library dependencies and ~6000 lines of source code but the gzipped bundle size comes out to ~97 KB. Just because you're building an SPA doesn't mean you need to spend less time optimizing your code, in fact it likely means the opposite.
- jamra 9y ago
  I’ve used React in the past and I believe what you’re mentioning is very React specific. Angular has lazy and eager loading, which reduces bundle sizes. It also doesn’t require so many frameworks to manage manually. They are still there, but they are sort of imported automatically by angular cli so it doesn’t take a lot of mental overhead. Some issues I had, though, were with bugs in newer versions. Some of those issues stopped development outright. Another issue I have on one team is the fallacious notion that the front end programmer will take over the front end so no one else will need to think about it. Business specific logic seems to be out of reach for my particular developers, which prolongs the development cycle. The benefit of state management and inter component communication have to be balanced the the practicality of who is doing the work and if those people can take ownership of all associated areas touched by the SPA.
  - swyx 9y ago
    is there a way for React to do eager loading? i asked around on twitter but got told "thats not React's job".
smnrchrds 9y ago
Tangential question: what is the best practice for handling authentication on a SPA? I have seen JWT being heavily criticized on HN and elsewhere. What is the alternative that still maintains the separation between front- and back-end?
- navd 9y ago
  Like anything else it depends. JWTs are still great. Just don’t treat it like a classical session and dump important information in it. You could also use session like you always have if the SPA is being served by the same server.
  - snuxoll 9y ago
    JWT is at the heart of OpenID connect, I agree they’re still perfectly reasonable. The big issue I have with JWT is they are hard to invalidate for security reasons, but if you lower the validity and refresh the token more often you can mitigate (not eliminate) the risk.
- san_at_weblegit 9y ago
  Tangential answer: It would vary based on sensitivity of your application. JWT is not a bad option if we do not have a requirement of absolute session termination and if implementation does not have any vulnerability. People also use cookie shared on the root domain(backend and front end can be served by different sub domain. Also you can use custom headers since cookie is just another type of header managed by browser itself. The additional work would be around managing the additional header on back end. People generally open doors for CSRF attack by separating front end and backend like this. Good thing is that there are simple solutions to mitigate that risk too.
maligree 9y ago
Is anything ever? Why is there such a strong tendency towards treating things as a this-is-it(-this-time-for-real) thing? This only confuses people and muddles up expectations.
yeeeeeeeeee 9y ago
This isnt a problem with SPAs per se, just a problem with the app's design. You can split SPAs into multiple apps that communicate. The main app would be loaded on open and the rest of the source could be pulled in when needed. React is not the cause of slow loads, your architecture is.
rhizome 9y ago
Can we start a movement to teach tech bloggers what "begging the question" is?
Illniyar 9y ago
This might not be a popular opinion here, but yes, SPAs are indeed a silver bullet. Or at least, no you shouldn't make a site that isn't SPA. With universal rendering, light frameworks like Preact/Inferno.js and things like microjs.com , you can make a site that loads faster, renders faster and navigates faster then a multi-page application. You can make SPAs behave like a regular site - with links that work and all. It's simply that many developers/managers don't care for or know how to make fast websites with SPAs, but then again even Multi-page applications are usually bloated with dozens of marketing, analytics and third-party libraries which makes them just as slow. I don't think reloading the entire page on every request is acceptable in 2018, even if it's a blog.
sebringj 9y ago
I thought gatsbyjs was a nice medium ground. You have the familiarity of a single-page app in terms of stack and yet have the quick loading times and back button, SEO all of that since it produces a static site. I thought it was genius but I'm biased because I like react.
- erlend_sh 9y ago
  Agreed. The old CERN website is pretty fast, but Gatsby actually loads subsequent pages much faster — hardly any discernible delay.
- _sdegutis 9y ago
  Funny you mention it, I just started looking into rewriting my portfolio website (http://sdegutis.com http://sdegutis.com) from a custom node-based static site generator to use Gatsby.js, in order to get more practice with React.js. Really curious to hear what other HN regulars who've used Gatsby think of it...
  - sebringj 9y ago
    I used it actually because I love react but needed to work with a great designer who already knew sass and I needed to include react components but also wanted to hook it up with a cms too. Check check check... keeps going and produces a static site. Wow. Even the designer could use this and modify things for simple components, not knowing react. I'm pretty happy so far.
throwaway0255 9y ago
One thing I'm noticing about SPAs is that they're often slower to load, but the slowness and loading animations gives me a higher perception of the quality of the application. The same application loading and doing things instantly as server-side templates feels comparatively cheap and un-modern. What is wrong with me?
- thehardsphere 9y ago
  Just a guess: You were alive when progress marched on before your eyes. Animations are "new" to you, and like many people you have some sort of implicit association somewhere in the back of your mind that "new == better" Do you ever find some animations to be lower quality than others? E.g. a pop up with a progress bar being lower quality than a spinning wheel? That might be another sign.
- pugworthy 9y ago
  Maybe to this day, Zombo.com is just an SPA that nobody every gave enough time to totally load. I mean after all, it was written in the late 90's and SPA technology wasn't that sophisticated back then.
eadmund 9y ago
I recently started blogging again, and I chose to go with a static site generator. It's fast, really fast. Loading a whole page with each click is so much faster than visiting most of the sites I visit each day. I'll never get why we collectively decided that it's reasonable to grant every random website in the world execute permissions on our machines.
mnm1 9y ago
Over 90% of my web browsing is done with JavaScript turned off. When I hit an spa blog I sometimes read it, sometimes not. Clearly if the owner of the blog is so insensitive as to make it an spa, they don't care about the content and especially don't care about their readers. That's fine. There's plenty of other content on the web to read. I don't understand why it's normal to let strangers run code on my computer. Yes, the masses are ignorant of the consequences, but I think that's slowly going away as me generations grow up with the internet. Anyway, the upside is that over 90% of web pages I visit load under a second. Imo, people who make their blog, marketing site, etc. an spa blindly don't care about their content, presentation, or the reader. Why would the reader care about them?
buzz27 9y ago
I was thinking about this recently watching a major web app throw a bunch of errors and slowdownsall to do with its SPA features. If it was just a normal web app it would be so much faster and more usable. It seems crazy to me that we have faster and faster computers and internet connections, and yet we've added all this new latency to the software we use. I find the list of pros somewhat unconvincing. For a lot of applications, a reload is no hardship, and is faster than most SPA interactions I see. For a lot of granualar actions, jquery, while not sexy, is not harder to maintain than a full SPA would be. The alleged development efficiency of decoupling front from back really needs context and argument. As I see things, there are a lot of web projects where a normal app with a little progressive enhancement is a good solution.
fictionfuture 9y ago
Hold up, most these problems are directly related to the problems of using React+redux (JSX) and likely some complicated backend stuff. We use Vue + Firebase and even have SSR working w no complaints. (So it's actually more than just a SPA)
oaiey 9y ago
Just a reminder: https://varvy.com/pagespeed/wicked-fast.html https://varvy.com/pagespeed/wicked-fast.html
digi_owl 9y ago
Frankly SPAs should be served up via a whole different channel, they are effectively an abuse of web tech to NIHing the likes of VNC.
- intelhearts 9y ago
  That's actually not a bad thought, it would be neat to think about how divorcing a lot of these javascript/bundles applications from http could be beneficial
nikkwong 9y ago
From a development perspective, in my humble opinion the single biggest hurdle with developing SPAs vs traditional server side applications are problems dealing with state consistency. The state model in non-spa apps is simple: when a pageload is requested, pull the latest state from the server. In SPAs the state has to be held on the client and server, and has to be able to react to state changes from the other side of the wire. Also I think that large bundle size being a mark against all SPAs is misleading. Yeah, angular is 1mb+, but vue is ~20kb, so the potential for the bundle to be small exists.
- Udik 9y ago
  > The state model in non-spa apps is simple: when a pageload is requested, pull the latest state from the server. In SPAs the state has to be held on the client and server, and has to be able to react to state changes from the other side of the wire My view is the exact opposite. Whenever you go through a page reload you lose the state on the client. And that has to be there, as it's what the user interacts with. You then need to send to the server a state which is not, strictly, an application state (it's a UI state) and that state needs to be taken in account by the server, and possibly merged with the application state, when generating the new page. A mess. On the other hand, a spa never loses its UI state, so you never need to recreate it. The server is also usually stateless, and simply satisfies the requests of the client. Basically you go from developing two separate applications with partly overlapping concerns to developing a single one, running on the client and relying on a service layer to query and persist its data.
sago 9y ago
> [SPA Pro:] frontend is decoupled from backend I was very surprised to read that. Very often validation and context-sensitive behaviour needs to be performed on the client and (since you can't trust the client) on the server. You can certainly argue this is better user experience: you don't have to wait for a server round-trip before finding out an action is invalid, but it's hardly decoupled. Isn't this a part of why node is so popular as a server platform? The stack is now so deeply coupled, it is very beneficial to reuse code.
- Udik 9y ago
  Repeated validations, while not DRY, aren't a case of coupling. They seem more a case of de-coupling, as they're needed for the application and the service layer to work independently from each other. While in non-spas your server receives from the client an extremely specific blob of page state plus user input and has to rebuild a specific new page with state updates and/or error messages.
photonios 9y ago
Some of the arguments the author mentions are not really good arguments. Basically it boils down to how much you care about the user experience. I designed and developed a SPA for a large real-estate portal in <6 months. I think we've nailed all of the points the author mentioned: - Initial request is rendered server-side, so TTI is extremely low. Even if the JS hasn't kicked in, the website is already usable. - Back button works perfectly fine. We use the HTML5 `history.pushState` method to add new entries to the history stack. - Links are always rendered as anchor tags. So even if the onClick handler fails or the JS crashed, the link will still work. - Compress the hell out of the bundle. Clocking in at 190KB compressed. (Edit: should do something about this, should be <100KB) Basically, we have most of the advantages of rendering "static" pages, yet also get all of the advantages of an SPA. We can do pre-loading in search results for example. If you click a link in search results, we immediately render the page and use the data from the search result to show a basic page and then slowly enhance it. This powers a large real-estate website that receives hundreds of thousands of visits a week. For this kind of business, a lot of stuff is important to get right. SEO related optimisations are extremely important. Hence, we server-side render everything to make sure the GoogleBot can read it all. The same applies to links. We keep our bundle size as small as possible to keep things speedy. Oh, and I personally got a kick out of spending a weekend to make the website function perfectly well without JS.
- JohnnyCrazy 9y ago
  Do you mind telling which stack you're using?
  - photonios 9y ago
    React 16, Redux, Webpack, a custom router. All transpiled using Babel. On the back-end we also use Python/Django. Nothing out of the ordinary :)
    - OffTheRails 9y ago
      This is great to see. I've been developing in Rails for the last 5 years, and am about to build my own products, and am opting for this kind of setup.. though have decided to hop over to Elixir on Phoenix, and will swap out Redux for Mobx. The application is mostly a dashboard (SaaS). Could easily be an MPA, but I want to move into more responsive UX, and wouldn't mind leveraging the portability for when I develop mobile or desktop apps. It seems majority of these responses against SPAs are, as you said, all based on bad design, not because the architecture itself is fundamentally flawed -- though it is obviously going against the grain by breaking a lot of this functionality in the first place. Having said that, the fact that browsers are providing native features to support SPAs, while bridging mobile-native features, is a massive sign of things to come. They're not going away, and support will only get better, and they will only become easier to develop. Anyway, I'd be interested to hear about your custom router! Any particular reason you rolled your own? I was planning to just use react-router, but if there are headaches down the road in terms of managing a hybrid SPA with SSR, I'd appreciate the heads-up.
mwcampbell 9y ago
For the problem of bundle size, it saddens me that Google's Closure Compiler (specifically the advanced mode) hasn't gained much traction. This provides fine-grained tree-shaking to minimize the bundle size. But this requires static analysis of the whole program, which is at odds with the dynamism of JavaScript. Maybe now that static typing is coming back into fashion, the Closure Compiler or something like it will gain widespread adoption.
- bpicolo 9y ago
  There's a number of projects out there working to reuse closure compiler bits on top of typescript. e.g. https://github.com/angular/tsickle https://github.com/angular/tsickle
osrec 9y ago
We built one of our products as an SPA (https://usebx.com/app https://usebx.com/app). I have to say it was a fairly enjoyable experience, and our users like it too (they often add it to their home screen and comment that it feels totally native). The only annoying thing was ios Safari, which has it's own little quirks in certain areas (but those are not limited to just SPAs but any kind of website).
- chrisper 9y ago
  Your app is breaking the back button on Firefox beta. That's in the demo. I wasn't able to get back to HN.
  - osrec 9y ago
    Yes, that's something we're looking to fix. I know it's annoying, but it's because of the somewhat unpredictable nature of onpopstate in a number of browsers (at least at the time of development). We'll probably do a full clean up of any related hacks in a couple of weeks and the issue should disappear!
- chillybean 9y ago
  That's a very cool app. I gave it a try when you first posted it on HN and now I'm a regular user! I find it much better than similar native apps, especially because of the offline mode (most invoicing apps seem to lack this). Anyway, thank you for the free tier - works a treat for my needs!
  - osrec 9y ago
    You're welcome, glad you like the app :)
jaunkst 9y ago
When you need an SPA it’s great. JQuery noodles are a past time and I’m not going back. If you need a blog or something just render it all sever-side and sprinkle some JS.
- meesterdude 9y ago
  > JQuery noodles are a past time and I’m not going back I love me some jQuery noodles! For some sites it becomes unwieldy i'll agree, but when sprinkled it provides a lot of enhancement.
scarface74 9y ago
I have mixed feelings about SPAs. I'm mostly a back end developer but do have some front end experience. On one hand, I think life is a lot simpler with server side rendering. On the other hand, I like the purity of REST APIs and front end rendering. For technical reasons not worth getting into, on my current project, a SPA would be overkill and hard to implement. But I did take the lessons I learned from my time with Angular to create a poor man's model view framework with a combination of HandlebarsJS+JQuery. After my experience doing it, I understand why a framework would be better. I'm reinventing the wheel (out of necessity), it wouldn't scale to multiple developers without becoming an ungodly mess without a framework to keep people on the rails and it would be harder to ramp people up. When I got thrust into my first Angular project it was easy just to read a few articles and watch some PluralSight videos. As the dev lead, I will definitely choose a SPA framework when my next front end project comes up. For all of the reasons above and because it's easier to recruit and retain people when you're doing the new and shiny that can add to someone's resume - including mine. It doesn't matter how I feel about the most popular frameworks, if I want to be employable, I need to keep up to date.
est 9y ago
been a victim of shit corporate SPAs 1. tons of widgets/slides/inputs in one single page 2. click submit -> error -> go back -> all filled info gone 3. cant open links in new tabs 4. cant copy shit off the inputs because text was in some kind of fake div with v-data attribute with disabled cursor movements. Had to use devtools to copy shit 5. Naturally, cant paste shit. Had to manually type MD5 checksums. 6. Always got redirect to home page after login 7. Broken links everywhere. Cant restore page state via link. IDK if this page is broken or still ajax in-progress. Had to open devtools to see if there's any js errors 8. If page is broken, refresh, boom, all your typed contents and procedures are gone. I think if people cant make a proper "multi" page form based web application, they should not be allowed to engage SPA at all.
jaxn 9y ago
What about applications that are used day-in and day-out? Applications that average dozens of "page views" per session. It seems that an initial load is worth a better UI.
tatersolid 9y ago
A lot of misinformation here. SQL Server has had check constraints since at least the year 1996.

196 points by bloomca 9y ago

Not the most compelling list of pros/cons that I have ever seen. In terms of raw performance for content sites, I found hybrid implementations like Gatsby.js to beat most things. Most of the cons of SPAs can be significantly diminished with SSR, proper chunking, and a variety of other modern techniques -- it just gets complicated in a hurry.

ryanworl 9y ago
For anyone reading this thread and thinking about server side rendering their single page app: do not go down that route unless you’re willing to also implement proper chunking! If you SSR your pages, but still need to load a giant bundle, you will get the worst of both worlds: a page that looks ready, but makes your users extremely frustrated because they can’t interact because your app isn’t booted yet.
piranha 9y ago
What's chunking in this context?
- ryanworl 9y ago
  Breaking down your JavaScript bundles into smaller files that contain the code necessary for the route you’re actually going to be viewing once the page is loaded. For other routes, you fetch the necessary code on-demand. This lessens the CPU power and bandwidth needed to initially load the page.

baddox 9y ago

> broken “open in a new tab” behaviour – people like to handle links in onClick handler, and browser can’t recognize it as a link (even if the majority of the links are valid, sooner or later you’ll encounter a non-link “link”) This one annoys me the most, but I will say an analogous problem is fairly common on non-SPA web sites, where reloading a URL doesn’t work as expected.

wavefunction 9y ago
That's usually just a lack of basic engineering practices common to well-implemented SPAs. All requests below the SPA's root should be forwarded to the SPA root, which appropriately then routes the request to the proper views and controllers. Proper usage of resource IDs in these URLs allows a newly initialized application model to populate and serve the appropriate content for the appropriate views.
- userbinator 9y ago
  The point is that browsers already have built-in code to interact with links and such in a predictable and straightforward manner, and your suggestion that "a lack of basic engineering practices", implying all SPAs need to reimplement that functionality, shows just how absurd the situation is.
  - wavefunction 9y ago
    The fundamental difference between a SPA and traditional website is that the routing and compositing of views is generally handled by the client rather than the server. It doesn't make sense to call something that doesn't respect that design a SPA. A poorly implemented SPA is what I would call that.
    - wavefunction 9y ago
      Zero contrary posts pointing out where I'm possibly wrong but them vote-brigading remains. Hackers News '18, folks.
  - bhldr 9y ago
    Most SPA's don't, because most frameworks have some built-in functionality for this.
  - manigandham 9y ago
    There's nothing to reimplement. Browsers navigate based on URLs, so if the URL for a page in an SPA isn't enough to load the full state on a fresh pageview, then it won't work. So it's absolutely about proper engineering to make sure pages have working direct URLs rather than just relying on other navigation while the app is already open.

burlesona 9y ago

One of the ways that I prefer to judge a JavaScript framework is (1) what is the minimum payload to use it, and (2) how nicely does it play with a hybrid app? In practice I’ve found VueJS does pretty well in this regard. Rather than build a full SPA I can sprinkle a few components here and there on pages that are highly interactive. The rest of the mostly static screens on my app are perfectly happy to be rendered from the server. It can be hard to strike the right balance between developer friendliness (ie maintainability and extensibility) versus user experience (ie speed and backwards compatibility) these days, but as always it’s important work to deliver the best user experience we can, and I agree with the author that SPA are not always the right choice in this regard.

unclebucknasty 9y ago
>Rather than build a full SPA I can sprinkle a few components here and there on pages that are highly interactive In practice, I've found "hybrid" apps hard to pull-off. In my experience, the question becomes, where do you draw the line? Take the simple/common case of presenting a list view. From the list, you want to allow the user to click to view details, which you then present dynamically--maybe in an overlay. It's a great user-experience. Everything pops, the user can easily return to the list view without a full page-load, etc. But, you now have a details view that is not reachable directly via its own URL. So, you use the framework's routing capability to assign one. Now, things are getting weird, because you're routing a dynamic view on top of a server-rendered one. You'll likely end up finding that you'll have to route the server-view as well for general navigability. And, you also have to account for people hitting the details URL directly (i.e. render the proper underlying server view, then let the client route to the dynamic URL). Not to mention the back-button. All manageable, of course. But, it gets messy to maintain such a hybrid approach. By the time you've integrated the routing, etc. the question becomes why hybrid? Why not full SPA? If your app is super-simple wherein you're just doing the tiniest bits of dynamic stuff and you don't need things like first class URLs, navigability among dynamic content, etc. then, yeah, maybe. But, that's not really a hybrid-SPA solution because there's no SPA there. In fact, I'm not sure there is a such thing as "hybrid-SPA". By definition, seems it's either a SPA or it's not.
- 9y ago

adamnemecek 9y ago

One thing that doesn’t get mentioned is that writing an SPA feels more like programming. Writing jquery feels like idk...not quite like programming.

kylnew 9y ago
It’s a lot more like writing a native mobile app, that’s for sure. You manage data and state with a much more long-term mindset. A bad line of JS is equivalent to a crash if it halts the whole SPA from working and requires a refresh.
mythrwy 9y ago
I'd about say the opposite. Organizing all your jQuery into meaningful classes and keeping the whole thing organized and orchestrated is very much the essence of programming. It's a rare skill (as a trip through many large jQuery code bases reveals). Filling in some templates causing magic to happen behind the scenes on the other hand, not so much. That being said, 1) are we interested in feeling like programmers or in pumping product? 2) if "pumping" is the answer, best tools depends on what is being done. All in favor or SPAs (when needed), but no, they aren't cooler than jQuery and are often big fat pigs that just shouldn't be used in that situation.
- unclebucknasty 9y ago
  >I'd about say the opposite. >Organizing...into meaningful classes and keeping the whole thing...orchestrated is very much the essence of programming >Filling in some templates causing magic to happen behind the scenes on the other hand, not so much. I'd agree and add that the different perspectives might be in large part due to the shift in programming away from procedural/code to declarative over the last decade or so. That is, if you started in coding over the last ten--and especially five years--you're much more likely to think of programming as declarative as much as code-oriented. And, the shift towards frameworks is probably the biggest driver of the declarative trend itself.
  - mythrwy 9y ago

seawlf 9y ago

I've worked on a number of SPA's over the years and I always run into the problem of getting my team to give a shit about performance. "We're not Google," they protest. Frankly for a lot of people it's the trade-off of slow client performance for development velocity. It's much easier to just throw on another state for new functionality than it is to consider what parts of the page can be static and how they can be rendered.

andybak 9y ago
Surely if you can't produce an SPA with equivalent or better performance than a more traditional architecture then - don't build an SPA. Or even better use a simpler solution that gives me 80% of the benefits of an SPA: Turbolinks, PJAX, intercooler.js or even a light sprinkling of good old AJAX. Does anyone remember "progressive enhancement"?
- tacone 9y ago
  Perhaps the most simple and trasparent solution to seamless navigation: http://instantclick.io/ http://instantclick.io/ As long as your backend is fast enough, it feels like navigating a SPA.
thehardsphere 9y ago
See, "we're not Google" should actually mean that you care about performance more. Google can throw millions of dollars worth of infrastructure into making an app go marginally faster. Whereas, all you have is brainpower before you deploy or ship. And it doesn't take that much more brainpower to get big increases in client performance when you're starting from not-optimized-at-all. The marginal payoff is larger and the marginal costs are much smaller.

jconley 9y ago

Many of these pitfalls can be avoided with intelligent server side rendering, which includes the router on the server, so no using client-only “#” URLs. But, that adds another significant layer of complexity to application development.

userbinator 9y ago

Half-expecting this article to itself be SPA, and was pleasantly surprised that it isn't. I agree completely with the author; there's some things (games and such come to mind) which certainly deserve to be SPAs, but the majority of the time it's a horrific waste for every single visitor to have to process MBs of data just to display a few KB of text and hundreds of KB of images (at most). Why? Just so developers can show off that feeling of how awesome they are for using some incredibly complex framework. That, and the ridiculous rate of churn, are probably what most irks me the most about the whole web development community (and why sites like HN appeal to me so much.) I'm not sure what's responsible for this "love of bloat", but IMHO we should be teaching developers how to do more with less, and not the complete opposite as seemingly happening today.

Can_Not 9y ago
> Why? Just so developers can show off that feeling of how awesome they are for using some incredibly complex framework. ... I'm not sure what's responsible for this "love of bloat", but IMHO we should be teaching developers how to do more with less, and not the complete opposite as seemingly happening today. I think you're misplacing the cause into developers. Developer's want to use the SPA framework because certain magnitudes of "application like UI" become maintainence nightmares for teams who stick with jQuery or use youmightnotneedjQuery. The reason they end up bloated or with random framework-supported elements broken (back button, etc.) is from what I call MVP culture. AIM and IRC were perfectly fine in the early 2000s, but instead of upgrading them for 2010+ they were abandoned or stripmined of value (Skype). Now we have slack, discord, flock etc.. releasing MVPs. Except apparently, they are perpetual MVPs. Many industries are encountering this. Developers at large are not permitted to rewrite in native languages, optimize any non-blocking performance issue, fix bugs that don't affect the bottom line. Everyone's trying to disrupt an industry so they can vendor lock in high profit rents. When we finish switching from typescript to reasonML and decide to switch from reasonML to Nim/kotlin-native, MVP culture will still be there to tell developers not to fix the broken back button.

andrenotgiant 9y ago

I always thought the decision was: - Content site = NOT single-page-app - Application = single-page-app Maybe there's more of a gray area between content sites and applications these days, but I think it's still pretty obvious: If most of the user's time is spent reading content, it's a content site.

thehardsphere 9y ago
That's a good starting point. I'd drill down even further and ask "what does the user do with the application?" If the user needs to look at multiple screens at a time (e.g. like a mail client or something of similar complexity), then they're a candidate for an SPA. If the user does not need to do that, the app is probably simple enough to not be an SPA.
motoprog 9y ago
I work in ecommerce and I feel it’s somewhere in between. We need to build for seo optimizations for the category/product experiences yet there is a lot of application like intersections, especially on the category filtering and the product sku selections. Quickshops, In store pickup modals, user specific recommendations trays, add and edit reviews et all. Different caching for server render at the edge vs personalized components adds another layer. Being able to serve with a shared routing scheme both client side (for improved performance) and server side for faster initial page load and seo on non-Google crawlers is a tough problem. Especially when you add in client hydration of the redux store. That parse time is a real killer on mobile. You add in service workers and prefetching and the complexity ratchets up further. The other issue we deal with is marketing pixels and trackers. But that’s another story. There is a ton of complexity in building a highly functioning ecommerce site.
- ccachor 9y ago
  Is it really worth the trade-off? I remember eCommerce sites trying to do similar levels of interactivity with Flash too. I just think, for a catalog site, it seems like you're trying to swim upstream. Especially on mobile.
9y ago

thehardsphere 9y ago

The problem with SPAs in the sort of cases that the author is talking about is that people don't think clearly about what requirements they are satisfying when writing a new one. If your app actually needs to switch between various screens without a refresh so your users can most efficiently get their work done, then yes, by all means, make an SPA. That requires knowing clearly who your users are, what they want to do, and what constraints they are under (e.g. if they all work on desktops with good internet access, maybe it doesn't matter that your app is bloated and slow on mobile). I think most people don't do that thinking step first. They want to play with the new shiny, either as a sort of fun or so they can add it to their resume. This I think is made worse by the unparalleled decadence in which the modern, first-world developer now lives. It is absolutely excessive to have to download 2.6 MB just to show a blog or some simple textual information, but thanks to broadband everywhere and terabyte hard drives, nobody under the age of 30 who isn't working in embedded systems thinks about this anymore.

tzakrajs 9y ago

"Stop writing only SPAs" is advice in the same way as "stop making only left-hand turns". This article stops short of convincing me to stop biasing towards SPAs because it appears only to reiterate known challenges about SPAs and calls out bad practices (tons of unused javascript libraries). SPA frameworks are pretty damned good and they really can and ought to be used wherever you feel the need because some SPA frameworks are very quick to get started with and can be customized to significantly reduce bloat.

JohnnyCrazy 9y ago

TBH most of the cons stated in this article are just because of bad programming, not because it's a SPA > broken “back” button (sometimes it works properly, but in general people don’t trust it) If your UX is good, the user will notice data is refreshed when going back. All current top tier SPA Frameworks have support for correct HTML5 routing. > broken “open in a new tab” behaviour – people like to handle links in onClick handler, and browser can’t recognize it as a link (even if the majority of the links are valid, sooner or later you’ll encounter a non-link “link”) Again, most up-to-date frameworks have a fallback by adding a normal href so you can still CTRL-Click it. > sometimes broken “refresh” button – after refreshing you end up in a different UI (usually slightly, but still different) I don't see a real disadvantage here, since you can simply store your state by manipulating the URL or even localstorage. So you even have the possibility to not store your state...But again, application design, not SPA I do agree with TTI (at least on the first load) and bad performance on low end devices.

jordache 9y ago
No. Because it is an SPA, it means there is more work to restore the default behavior of the back button. That's the way he should have articulated his point. You also mention HTML5 routing.. Ok now you have to configure your web server to properly parse the URL and understand what it's conveying.
- Can_Not 9y ago
  And all of that work is already done for you in all modern major SPA frameworks.
  - jordache 9y ago
    Server side too? Client side routing? Have you seen the huge chapter dedicated to routing for angular? You make it sound like it's no work
    - Can_Not 9y ago

geraldbauer 9y ago

Great to see the article posted on a "classic" (static) website built w/ jekyll. Find more open source (ready-to-fork) themes @ https://drjekyllthemes.github.io https://drjekyllthemes.github.io Build your own "classic" websites / blogs :-).

vincentriemer 9y ago

As an avid developer of SPAs (currently working on one for my own blog frontend) I'd say a lot if this stems from people being convinced SPAs 1) provide a faster development cycle, 2) they believe that they've offloaded all need for optimization on the framework they use and 3) "serious" development teams build SPAs. Anecdotally I find SPAs, while I'm more comfortable developing them, will take longer to build. You need to pay more attention to the quirks the author mentions and you need to spend more time explicitly optimizing your code. I like this paradigm because if there is inconsistent logic, poor performance, or other issues, it's my fault and I have the opportunity to fix it. As a counter example to the ones mentioned in the above article, around 2 years ago I build a drum machine webapp entirely in JavaScript/React (https://io808.com https://io808.com). This has ~17 JS library dependencies and ~6000 lines of source code but the gzipped bundle size comes out to ~97 KB. Just because you're building an SPA doesn't mean you need to spend less time optimizing your code, in fact it likely means the opposite.

jamra 9y ago
I’ve used React in the past and I believe what you’re mentioning is very React specific. Angular has lazy and eager loading, which reduces bundle sizes. It also doesn’t require so many frameworks to manage manually. They are still there, but they are sort of imported automatically by angular cli so it doesn’t take a lot of mental overhead. Some issues I had, though, were with bugs in newer versions. Some of those issues stopped development outright. Another issue I have on one team is the fallacious notion that the front end programmer will take over the front end so no one else will need to think about it. Business specific logic seems to be out of reach for my particular developers, which prolongs the development cycle. The benefit of state management and inter component communication have to be balanced the the practicality of who is doing the work and if those people can take ownership of all associated areas touched by the SPA.
- swyx 9y ago
  is there a way for React to do eager loading? i asked around on twitter but got told "thats not React's job".

smnrchrds 9y ago

Tangential question: what is the best practice for handling authentication on a SPA? I have seen JWT being heavily criticized on HN and elsewhere. What is the alternative that still maintains the separation between front- and back-end?

navd 9y ago
Like anything else it depends. JWTs are still great. Just don’t treat it like a classical session and dump important information in it. You could also use session like you always have if the SPA is being served by the same server.
- snuxoll 9y ago
  JWT is at the heart of OpenID connect, I agree they’re still perfectly reasonable. The big issue I have with JWT is they are hard to invalidate for security reasons, but if you lower the validity and refresh the token more often you can mitigate (not eliminate) the risk.
san_at_weblegit 9y ago
Tangential answer: It would vary based on sensitivity of your application. JWT is not a bad option if we do not have a requirement of absolute session termination and if implementation does not have any vulnerability. People also use cookie shared on the root domain(backend and front end can be served by different sub domain. Also you can use custom headers since cookie is just another type of header managed by browser itself. The additional work would be around managing the additional header on back end. People generally open doors for CSRF attack by separating front end and backend like this. Good thing is that there are simple solutions to mitigate that risk too.

maligree 9y ago

Is anything ever? Why is there such a strong tendency towards treating things as a this-is-it(-this-time-for-real) thing? This only confuses people and muddles up expectations.

yeeeeeeeeee 9y ago

This isnt a problem with SPAs per se, just a problem with the app's design. You can split SPAs into multiple apps that communicate. The main app would be loaded on open and the rest of the source could be pulled in when needed. React is not the cause of slow loads, your architecture is.

rhizome 9y ago

Can we start a movement to teach tech bloggers what "begging the question" is?

Illniyar 9y ago

This might not be a popular opinion here, but yes, SPAs are indeed a silver bullet. Or at least, no you shouldn't make a site that isn't SPA. With universal rendering, light frameworks like Preact/Inferno.js and things like microjs.com , you can make a site that loads faster, renders faster and navigates faster then a multi-page application. You can make SPAs behave like a regular site - with links that work and all. It's simply that many developers/managers don't care for or know how to make fast websites with SPAs, but then again even Multi-page applications are usually bloated with dozens of marketing, analytics and third-party libraries which makes them just as slow. I don't think reloading the entire page on every request is acceptable in 2018, even if it's a blog.

sebringj 9y ago

I thought gatsbyjs was a nice medium ground. You have the familiarity of a single-page app in terms of stack and yet have the quick loading times and back button, SEO all of that since it produces a static site. I thought it was genius but I'm biased because I like react.

erlend_sh 9y ago
Agreed. The old CERN website is pretty fast, but Gatsby actually loads subsequent pages much faster — hardly any discernible delay.
_sdegutis 9y ago
Funny you mention it, I just started looking into rewriting my portfolio website (http://sdegutis.com http://sdegutis.com) from a custom node-based static site generator to use Gatsby.js, in order to get more practice with React.js. Really curious to hear what other HN regulars who've used Gatsby think of it...
- sebringj 9y ago
  I used it actually because I love react but needed to work with a great designer who already knew sass and I needed to include react components but also wanted to hook it up with a cms too. Check check check... keeps going and produces a static site. Wow. Even the designer could use this and modify things for simple components, not knowing react. I'm pretty happy so far.

throwaway0255 9y ago

One thing I'm noticing about SPAs is that they're often slower to load, but the slowness and loading animations gives me a higher perception of the quality of the application. The same application loading and doing things instantly as server-side templates feels comparatively cheap and un-modern. What is wrong with me?

thehardsphere 9y ago
Just a guess: You were alive when progress marched on before your eyes. Animations are "new" to you, and like many people you have some sort of implicit association somewhere in the back of your mind that "new == better" Do you ever find some animations to be lower quality than others? E.g. a pop up with a progress bar being lower quality than a spinning wheel? That might be another sign.
pugworthy 9y ago
Maybe to this day, Zombo.com is just an SPA that nobody every gave enough time to totally load. I mean after all, it was written in the late 90's and SPA technology wasn't that sophisticated back then.

eadmund 9y ago

I recently started blogging again, and I chose to go with a static site generator. It's fast, really fast. Loading a whole page with each click is so much faster than visiting most of the sites I visit each day. I'll never get why we collectively decided that it's reasonable to grant every random website in the world execute permissions on our machines.

mnm1 9y ago

Over 90% of my web browsing is done with JavaScript turned off. When I hit an spa blog I sometimes read it, sometimes not. Clearly if the owner of the blog is so insensitive as to make it an spa, they don't care about the content and especially don't care about their readers. That's fine. There's plenty of other content on the web to read. I don't understand why it's normal to let strangers run code on my computer. Yes, the masses are ignorant of the consequences, but I think that's slowly going away as me generations grow up with the internet. Anyway, the upside is that over 90% of web pages I visit load under a second. Imo, people who make their blog, marketing site, etc. an spa blindly don't care about their content, presentation, or the reader. Why would the reader care about them?

buzz27 9y ago

I was thinking about this recently watching a major web app throw a bunch of errors and slowdownsall to do with its SPA features. If it was just a normal web app it would be so much faster and more usable. It seems crazy to me that we have faster and faster computers and internet connections, and yet we've added all this new latency to the software we use. I find the list of pros somewhat unconvincing. For a lot of applications, a reload is no hardship, and is faster than most SPA interactions I see. For a lot of granualar actions, jquery, while not sexy, is not harder to maintain than a full SPA would be. The alleged development efficiency of decoupling front from back really needs context and argument. As I see things, there are a lot of web projects where a normal app with a little progressive enhancement is a good solution.

fictionfuture 9y ago

Hold up, most these problems are directly related to the problems of using React+redux (JSX) and likely some complicated backend stuff. We use Vue + Firebase and even have SSR working w no complaints. (So it's actually more than just a SPA)

oaiey 9y ago

Just a reminder: https://varvy.com/pagespeed/wicked-fast.html https://varvy.com/pagespeed/wicked-fast.html

digi_owl 9y ago

Frankly SPAs should be served up via a whole different channel, they are effectively an abuse of web tech to NIHing the likes of VNC.

intelhearts 9y ago
That's actually not a bad thought, it would be neat to think about how divorcing a lot of these javascript/bundles applications from http could be beneficial

nikkwong 9y ago

From a development perspective, in my humble opinion the single biggest hurdle with developing SPAs vs traditional server side applications are problems dealing with state consistency. The state model in non-spa apps is simple: when a pageload is requested, pull the latest state from the server. In SPAs the state has to be held on the client and server, and has to be able to react to state changes from the other side of the wire. Also I think that large bundle size being a mark against all SPAs is misleading. Yeah, angular is 1mb+, but vue is ~20kb, so the potential for the bundle to be small exists.

Udik 9y ago
> The state model in non-spa apps is simple: when a pageload is requested, pull the latest state from the server. In SPAs the state has to be held on the client and server, and has to be able to react to state changes from the other side of the wire My view is the exact opposite. Whenever you go through a page reload you lose the state on the client. And that has to be there, as it's what the user interacts with. You then need to send to the server a state which is not, strictly, an application state (it's a UI state) and that state needs to be taken in account by the server, and possibly merged with the application state, when generating the new page. A mess. On the other hand, a spa never loses its UI state, so you never need to recreate it. The server is also usually stateless, and simply satisfies the requests of the client. Basically you go from developing two separate applications with partly overlapping concerns to developing a single one, running on the client and relying on a service layer to query and persist its data.

sago 9y ago

> [SPA Pro:] frontend is decoupled from backend I was very surprised to read that. Very often validation and context-sensitive behaviour needs to be performed on the client and (since you can't trust the client) on the server. You can certainly argue this is better user experience: you don't have to wait for a server round-trip before finding out an action is invalid, but it's hardly decoupled. Isn't this a part of why node is so popular as a server platform? The stack is now so deeply coupled, it is very beneficial to reuse code.

Udik 9y ago
Repeated validations, while not DRY, aren't a case of coupling. They seem more a case of de-coupling, as they're needed for the application and the service layer to work independently from each other. While in non-spas your server receives from the client an extremely specific blob of page state plus user input and has to rebuild a specific new page with state updates and/or error messages.

photonios 9y ago

Some of the arguments the author mentions are not really good arguments. Basically it boils down to how much you care about the user experience. I designed and developed a SPA for a large real-estate portal in <6 months. I think we've nailed all of the points the author mentioned: - Initial request is rendered server-side, so TTI is extremely low. Even if the JS hasn't kicked in, the website is already usable. - Back button works perfectly fine. We use the HTML5 `history.pushState` method to add new entries to the history stack. - Links are always rendered as anchor tags. So even if the onClick handler fails or the JS crashed, the link will still work. - Compress the hell out of the bundle. Clocking in at 190KB compressed. (Edit: should do something about this, should be <100KB) Basically, we have most of the advantages of rendering "static" pages, yet also get all of the advantages of an SPA. We can do pre-loading in search results for example. If you click a link in search results, we immediately render the page and use the data from the search result to show a basic page and then slowly enhance it. This powers a large real-estate website that receives hundreds of thousands of visits a week. For this kind of business, a lot of stuff is important to get right. SEO related optimisations are extremely important. Hence, we server-side render everything to make sure the GoogleBot can read it all. The same applies to links. We keep our bundle size as small as possible to keep things speedy. Oh, and I personally got a kick out of spending a weekend to make the website function perfectly well without JS.

JohnnyCrazy 9y ago
Do you mind telling which stack you're using?
- photonios 9y ago
  React 16, Redux, Webpack, a custom router. All transpiled using Babel. On the back-end we also use Python/Django. Nothing out of the ordinary :)
  - OffTheRails 9y ago
    This is great to see. I've been developing in Rails for the last 5 years, and am about to build my own products, and am opting for this kind of setup.. though have decided to hop over to Elixir on Phoenix, and will swap out Redux for Mobx. The application is mostly a dashboard (SaaS). Could easily be an MPA, but I want to move into more responsive UX, and wouldn't mind leveraging the portability for when I develop mobile or desktop apps. It seems majority of these responses against SPAs are, as you said, all based on bad design, not because the architecture itself is fundamentally flawed -- though it is obviously going against the grain by breaking a lot of this functionality in the first place. Having said that, the fact that browsers are providing native features to support SPAs, while bridging mobile-native features, is a massive sign of things to come. They're not going away, and support will only get better, and they will only become easier to develop. Anyway, I'd be interested to hear about your custom router! Any particular reason you rolled your own? I was planning to just use react-router, but if there are headaches down the road in terms of managing a hybrid SPA with SSR, I'd appreciate the heads-up.

mwcampbell 9y ago

For the problem of bundle size, it saddens me that Google's Closure Compiler (specifically the advanced mode) hasn't gained much traction. This provides fine-grained tree-shaking to minimize the bundle size. But this requires static analysis of the whole program, which is at odds with the dynamism of JavaScript. Maybe now that static typing is coming back into fashion, the Closure Compiler or something like it will gain widespread adoption.

bpicolo 9y ago
There's a number of projects out there working to reuse closure compiler bits on top of typescript. e.g. https://github.com/angular/tsickle https://github.com/angular/tsickle

osrec 9y ago

We built one of our products as an SPA (https://usebx.com/app https://usebx.com/app). I have to say it was a fairly enjoyable experience, and our users like it too (they often add it to their home screen and comment that it feels totally native). The only annoying thing was ios Safari, which has it's own little quirks in certain areas (but those are not limited to just SPAs but any kind of website).

chrisper 9y ago
Your app is breaking the back button on Firefox beta. That's in the demo. I wasn't able to get back to HN.
- osrec 9y ago
  Yes, that's something we're looking to fix. I know it's annoying, but it's because of the somewhat unpredictable nature of onpopstate in a number of browsers (at least at the time of development). We'll probably do a full clean up of any related hacks in a couple of weeks and the issue should disappear!
chillybean 9y ago
That's a very cool app. I gave it a try when you first posted it on HN and now I'm a regular user! I find it much better than similar native apps, especially because of the offline mode (most invoicing apps seem to lack this). Anyway, thank you for the free tier - works a treat for my needs!
- osrec 9y ago
  You're welcome, glad you like the app :)

jaunkst 9y ago

When you need an SPA it’s great. JQuery noodles are a past time and I’m not going back. If you need a blog or something just render it all sever-side and sprinkle some JS.

meesterdude 9y ago
> JQuery noodles are a past time and I’m not going back I love me some jQuery noodles! For some sites it becomes unwieldy i'll agree, but when sprinkled it provides a lot of enhancement.

scarface74 9y ago

I have mixed feelings about SPAs. I'm mostly a back end developer but do have some front end experience. On one hand, I think life is a lot simpler with server side rendering. On the other hand, I like the purity of REST APIs and front end rendering. For technical reasons not worth getting into, on my current project, a SPA would be overkill and hard to implement. But I did take the lessons I learned from my time with Angular to create a poor man's model view framework with a combination of HandlebarsJS+JQuery. After my experience doing it, I understand why a framework would be better. I'm reinventing the wheel (out of necessity), it wouldn't scale to multiple developers without becoming an ungodly mess without a framework to keep people on the rails and it would be harder to ramp people up. When I got thrust into my first Angular project it was easy just to read a few articles and watch some PluralSight videos. As the dev lead, I will definitely choose a SPA framework when my next front end project comes up. For all of the reasons above and because it's easier to recruit and retain people when you're doing the new and shiny that can add to someone's resume - including mine. It doesn't matter how I feel about the most popular frameworks, if I want to be employable, I need to keep up to date.

est 9y ago

been a victim of shit corporate SPAs 1. tons of widgets/slides/inputs in one single page 2. click submit -> error -> go back -> all filled info gone 3. cant open links in new tabs 4. cant copy shit off the inputs because text was in some kind of fake div with v-data attribute with disabled cursor movements. Had to use devtools to copy shit 5. Naturally, cant paste shit. Had to manually type MD5 checksums. 6. Always got redirect to home page after login 7. Broken links everywhere. Cant restore page state via link. IDK if this page is broken or still ajax in-progress. Had to open devtools to see if there's any js errors 8. If page is broken, refresh, boom, all your typed contents and procedures are gone. I think if people cant make a proper "multi" page form based web application, they should not be allowed to engage SPA at all.

jaxn 9y ago

What about applications that are used day-in and day-out? Applications that average dozens of "page views" per session. It seems that an initial load is worth a better UI.

tatersolid 9y ago

A lot of misinformation here. SQL Server has had check constraints since at least the year 1996.