Flow type checker from Facebook is nice and all, but dead. Long story short, Nuclide died, Atom is dying, Flow is dying too. VSCode can be beautiful and minimal, etc. So, how to migrate of? Use https://github.com/flowtype/flow-remove-types to remove Flow stuff from your code. Rename .js files to .tsx … Profit! OK, it’s not so easy but isn’t hard neither. Check este-typescript for tips. Or hire me. https://javascript-skoleni.com or daniel@steigerwald.cz

As graphql.org says, evolve your API without versions. I don’t know how “@deprecated” directive works (TODO: Investigate it). But I know stale not yet updated app can fetch from new updated GraphQL API when API is updated but an app not. Then what? Relay compiler generates Flow types based on GraphQL schema, and leverages GraphQL non-nullable, so app will not crash, instead it will just not render some data. That’s fine, better to be stale than dead. Meanwhile, app should ask for update.

When I am teaching JavaScript and React, often my audience comes from traditional Java or C# world, so I need some sweet spot to justify all new stuff they need to learns, and, which is harder, all old stuff, they have to forget about. Such sweet spot is algebraic types…

Forms are often over-engineered. They don’t have to be. Let’s start with types. Why? Because types help us to think about architecture. Update: In https://github.com/este/este, you will found even more simple and concise and powerful example of modern typed universal validation. Types and validators ValidationError component to render validation error as message Example usage And that’s all. It’s explicit, typed, and clean.

Is pretty dangerous pattern because if an app is terminated before the end of some async process, the form will be disabled forever. The same for every temporally value in app state. We have to store disabled form fields state in local storage, to share app state across tabs. Separate local storage and session storage is possible, but hard to code without a lot of boilerplate. We can filter app state after storage rehydration, but again, it’s error prone and hard to implement easily.

If you like what I’m doing with github.com/este/este or whatever, please support further development. Bitcoin Address 15H9wHuJk7RPHfWPPCRtiUEBb7vX1iD7ui Transactions sent and received from bitcoin address 15H9wHuJk7RPHfWPPCRtiUEBb7vX1iD7ui.blockchain.info Thank you.

Server detects user agent locale and returns internationalized app, if possible. Server doesn’t redirect. With this approach, the same URL provides different content. It means, example.com/about will render both English or Czech content. I believe it’s ok because server also provides language annotations for crawlers. Therefore, cs.example.com/about will work as expected. Both for the user and the crawler.

Forms are hard. It’s the same as validation. No magic framework will save us from writing our app code. The wrong abstraction is the wrong abstraction no matter how hard you push the human limits. UPDATE: I made beautiful forms without Redux. Check it 🐕✨. Pokud vás zajímá více, pořádám…

From CSS to universal typed React UI bootstrap — UPDATE: I revamped design slightly and implementation a lot. Check Este next branch. UPDATE 2: This article is obsolete. Follow github.com/este/este for updates. For years, developers have been fighting with complexity and related bugs of cascading style sheets. I have seen many styles, written in dozens various methodologies or without…