malli VS re-frame

Clojure's lazy sequences by default are wonderful ergonomically, but it provides many ways to use strict evaluation if you want to. They aren't really a hassle either. I've been doing Clojure for the last few years and have a few grievances, but overall it's the most coherent, well thought out language I've used and I can't recommend it enough.

There is the issue of startup time with the JVM, but you can also do AOT compilation now so that really isn't a problem. Here are some other cool projects to look at if you're interested:

Malli: https://github.com/metosin/malli

Babashka: https://github.com/babashka/babashka

Clerk: https://github.com/nextjournal/clerk

BREAKING: walking a :schema passes children instead of [id] to the walker function #884

When you get to larger, more complex validations, I'd recommend checking out Malli or Spec.

for specs, you can try malli - feels pretty well supported and full featured: https://github.com/metosin/malli (i'm not 100% sure how popular it is for others, but I use it on my personal projects)

Have you tried malli: Data-driven Schemas for Clojure/Script?

All that being said, I particularly use malli and I don't find anything to complain about. There is a very nice and sound ecosystem being built around it (malli-ts is one of my contributions to it, but still in early development stages). I highly recommend reading its README, very informative stuff.

Any large codebase can be broken up into small isolated components that can be reasoned about independently. This is how you structure Clojure projects if you want them to be maintainable. Clojure inherently encourages doing this by defaulting to immutability. The contract between components is the data being passed to the component and returned by it. Using Malli schemas at the edges of the components is a typical approach to documenting their APIs https://github.com/metosin/malli

I see the fact that people often end up creating large and tightly coupled monolithic codebases in static languages as a negative aspect of static typing. Such codebases are difficult to reason about even if you have guarantees that the types align. Ultimately, you need to understand the relationships in code, and how they relate to business logic. The more coupling an application has the harder it becomes to reason about it as a whole.

Ideally, I think applications should be structured as a bunch of Lego blocks that can be composed together. Each component should encapsulate some functionality, and then the flow of the business logic should bubble up to the top and expressed in how these components are chained together.

Uhhh spec has existed for a long time and before that, schema Nowadays we also have the excellent malli. If his codebase is full of functions where the shape of the data isn’t obvious, isn’t documented and isn’t specified in a specific/schema, that’s on him and his bad coding practices and really no different from passing data in other dynamic languages. A class by itself (without additional effort) only gives you field names.

This article always reminds me of this excerpt from re-frame’s docs [0]:

> Now, you think and design abstractly for a living, and that repetition will feel uncomfortable. It will call to you like a Siren: "refaaaaactoooor meeeee". "Maaaake it DRYYYY". So here's my tip: tie yourself to the mast and sail on. That repetition is good. It is serving a purpose. Just sail on.

[0]: https://github.com/day8/re-frame/blob/master/docs/correcting...

* Single-Page App: shadow-cljs for the build concerns (https://github.com/thheller/shadow-cljs), Reagent with Re-frame for complex/large app (https://reagent-project.github.io and https://github.com/day8/re-frame). Even if we now prefer using HTMX (https://htmx.org) and server-side rendering (Hiccup way of manipulating HTML is just amazing, https://github.com/weavejester/hiccup).

Big and/or complete projects that use re-frame The main list: https://github.com/day8/re-frame/blob/master/docs/External-Resources.md

Reflet is a set of tools for building Re-frame + React based web apps with graph and non-graph data models. This includes:

https://github.com/day8/re-frame

Notably the author of re-frame has been weary of hooks.

I think that’s for a good reason. The approach in re frame feels like the best way to manage state so far for a react based app. Everything that changes state flows through an event. State can only be observed through subscriptions. Side effects are isolated to their own type of event. Debugging and testing are so straight forward with these concepts.

Redux got close but it has two problems in my mind. Like hooks, it encapsulates for no good reason. Put the state in one thing that you can observe holistically before and after pure events. It also has too much boiler plate.

The cljs stack I hear about a lot (and use) is ShadowCLJS with reagent (https://reagent-project.github.io/) and re-frame (https://day8.github.io/re-frame/). ShadowCLJS is more of a build tool, but is really well documented and easy to use. Reagent is basically react but a simpler API, and re-frame is a layer on top of that provides data subscriptions and event-handlers to manage app state. It's overkill for some apps but I find it's actually super easy to work with and not as much complexity as I thought.

For backend there is luminus (https://luminusweb.com/) or Kit (https://kit-clj.github.io/). They are basically project templates that wire together a ton of popular solutions for various things - database access, migrations, security, html templating, etc. Also includes frontend frameworks like re-frame if you want.

Reflet aims to be a natural progression on top of Re-frame to support complex, data driven requirements. In that sense, it is both easy to learn, but powerful. You could say it's sort of like Re-frame++ (or Fulcro for Re-frame). Its main design goals are:

At my current client we're working on having a frontend architecture for writing SPAs in JavaScript similar to re-frame's one: an event-driven bus with effects and coeffects for state management[1] (commands) and subscriptions using reselect's selectors (queries).

Some of us had worked with effects and coeffects before while developing SPAs with re-frame and had experienced how good it is. After working with re-frame, when you come to horizon, you realize how a good architecture can make a dramatic difference in clarity, testability, understandability and easiness of change.

https://youtu.be/geeK1-jjlhY (talk about an initial prototype with re-frame and the decision to do a rewrite in Clojure)