applin-ios VS turbo

> Beyond Python and React ... Implementing frontends for other platforms like mobile ...

Shameless plug: I built a mobile version of this: https://www.applin.dev

I built a thing that makes it much simpler to make apps: https://www.applin.dev

You make a web server that returns JSON defining your UI. Then you make a native iOS app by copy/pasting the provided Main.swift file and adding the URL of your server. The app uses an iOS client library, fetches the JSON page definition, and builds/updates the page with native widgets. I'm planning to eventually build Android, web, and desktop clients.

Hi HN, I'm a backend engineer who made an app and didn’t like the tools. Then I made the thing I needed: a mobile app toolkit for backend engineers. I'm calling it Applin™. :)

https://www.applin.dev/

How it works: You make an HTTP server that returns JSON objects that define page content. Then you make a mobile app that calls the server and renders the pages using native widgets. Applin is the server and client libraries that make this easy.

Server libraries: Currently there's Rails https://rubygems.org/gems/applin-rails and https://github.com/leonhard-llc/applin-rails-demo . Which languages shall I add next?

Client libraries: Currently there's iOS https://github.com/leonhard-llc/applin-ios . Which platform shall I add next?

They say, if you're not embarrassed by the quality, then you're launching too late. Applin is usable and not yet pretty and not yet comprehensive. I need customer feedback on priority and requirements.

To try it out right away, use https://apps.apple.com/us/app/applin-tester/id6464230000 and tap the rails-demo link.

The hardest part of this project was making the client update the page without losing keyboard focus and scrolling to the top. To do that, the code must pick the correct existing widgets for each new version of the widget tree. The current (working) version performs five passes over the widget tree: first picking focused widgets and their ancestors, then focus-able widgets, then other stateful widgets, then widgets with matching attributes (label, URL, etc.), and finally former siblings of the correct type. Then it creates any new widgets. Now that it has widgets for the new tree, the code updates the widget tree without removing any sub-widget that will be added again. This prevents losing keyboard focus and prevents resetting scroll positions. Here's the code:

https://github.com/leonhard-llc/applin-ios/blob/main/Sources/ApplinIos/page/widget_cache.swift

Please try out Applin, use it at your company (buy a license), and let me know what features to build first! Post a comment here, add a GitHub issue, or email me at [email protected] .

To get updates, join https://groups.google.com/g/applin-announce .

Thanks for reading! :) --Michael

I also recommend checking out the docs for Stimulus and Turbo to familiarise yourself with all their features and the APIs used in this series.

https://github.com/hotwired/turbo

Turbo 8 remove typescript without using JSDOC

Experiment using Turbo to drive front-end behavior: "Turbo 7.2.0 (currently in beta) allows you to define your own Stream actions which can be any JS code you want. By combining a custom Stream action or two with web components, you can essentially drive reactive frontend behavior from the backend stupidly easily. Loooove it! 😍 […] For a turnkey example, you could check out https://github.com/hopsoft/turbo_ready " —Jared White on The Spicy Web Discord

This handles disconnection (as could be done by any destructive change to the DOM, like navigating with Turbo or htmx, I'm not even talking about using the element in a JavaScript-heavy web app) but not reconnection though, and we've exited early from the connectedCallback to avoid initializing the element twice, so this change actually broke our component in these situations where it's moved around, or stashed and then reinserted. To fix that, we need to always call addSparkles in connectedCallback, so move all the rest into an if, that's actually as simple as that… except that when the user prefers reduced motion, sparkles are never removed, so they keep piling in each time the element is connected again. One way to handle that, without introducing our housekeeping of individual timers, is to just remove all sparkles on disconnection. Either that or conditionally add them in connectedCallback if either we're initializing the element (including attaching the shadow DOM) or the user doesn't prefer reduced motion. The difference between both approaches is in whether we want the small animation when the sparkles appear (and appearing at new random locations). I went with the latter.

If you think you have seen enough Rails magic, you are mistaken my friend. Rails have a new trick up its sleeve: Hotwire. And with the magical Turbo tool that comes with it, you can create modern, interactive web applications with minimal, or sometimes no JavaScript at all, providing users with an incredibly smooth experience.

There is also Turbo and the frameworks who adopt them, Ruby on Rails, PHP Symphony and possibly others that solves the same issue in the same manner as HTMX. And the choice for HTMX is only a personal taste in this, but you should definitely learn about this, this is as cool as HTMX!

Most controversially, the Turbo framework dropped TypeScript support altogether after assessing that strong typing was the culprit behind poor developer experience.

Turbo[0] has been solving this for years. Quite the contrary, front-end frameworks have started to think "sending JSON is good, but actually sending HTML could be great!".

DHH's presentation[1] during Rails World 2023 is quite interesting in that regard, I recommend you give it a go (start around minute 16). I am actually very excited with his vision of the web.

[0] https://turbo.hotwired.dev/