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ecto queries in liveviews and controllers? discuss. 🍿 #ElixirLang #phoenix #code

My thinking on this one has evolved after working on some medium to large-scale code repos. When I started writing code professionally, I had absorbed some of the best practices common in MVC frameworks, DDD, and other programming patterns. btw, thread length != rage 😜

In my first coding gigs, I experienced first-hand the impact of poorly organized code. SQL queries were scattered throughout template code, everything was mutable, and debugging was painfully tedious. I scoffed and rolled my eyes.

Later, I followed the patterns laid out by the Phoenix code generators. Where contexts contained CRUD code, controllers and LiveViews called those context functions. One of the biggest pain points that has grown out of this pattern, though, is query code - specifically *reading* data from a Repo.

While I can imagine some applications that have identical queries used across multiple call sites, this hasn't been my experience. Instead, I've seen hastily added functions in contexts which serve a single call site elsewhere in the codebase. These functions often have hilariously long names.

Really interesting comparison. Do you see an overlap between the ways the SPA world tackles CSS issues and this ecto query question? Abstractly they feel a little similar to me. In addition to CSS I also often find SPA data queries living close to calling UI component code with some utility helpers.

Years ago, I heard a hot take on a podcast that stuck with me and I've been taking it more seriously in the past few months. Something along the lines of "just write the query in the controller/LV and move on with your life." IIRC, this was a classic Chris Keathley hot take.

Now, this probably feels like heresy. I didn't start writing queries in my LVs until I was exhausted from the ritual of managing queries in contexts. When I'm in a LV, I know what data I need for its specific use case. I only need to name a local variable and a socket assign. No abstraction needed.

Keeping the create, update, and delete code in a context still makes sense. In fact, I've been venturing out into CQRS land and enjoying the strictness and atomicity of the modules we've created lately. What seems to be contentious is that I'm advocating for single-use Ecto queries inside LVs.

I personally find it very frustrating to look at code in the eg Phoenix auth generator style where there are contexts and then you look at the function and it’s like a “Repo.all”. I find queries to be the easiest thing to read, and often as short, so when I have to trace a function call to