elm-spa-example VS Concourse

About 7 years ago, in the midst of writing Elm in Action, Richard Feldman developed rtfeldman/elm-spa-example, wrote Tour of an Open-Source Elm SPA and graciously shared both of them with the Elm community. The community's response was overwhelmingly positive and it was clear that he had addressed a major need. If you were one of the many web application developers asking "Where can I find an open-source example of an Elm Single Page Application?", then, the Elm SPA Example instantly became the canonical example that everyone was going to point you towards. This was a landmark achievement in the history of Elm.

One accidentally nice thing about that book is the elm version is still the same, so everything is still relevant. As for the SPA, I think the book had to keep things simple, but you'd probably want to look into the author's elm-spa-example next, there's a talk on youtube that goes along with that and he also also a related course on frontend maters worth exploring.

I'm following along with the update behavior of https://github.com/rtfeldman/elm-spa-example/blob/master/src/Main.elm. But I'm not sure how I propagate a message from Main.elm to User.elm to Table.elm (or deeper). How do you manage Msg passing like this?

I am building my first Elm app just following the docs from the official web site. I don't see any direct mention of styling there. Looking around, I see the elm-ui project is one, elm-css is another approach, and the example SPA that Richard Feldman made just uses a stylesheet from Bootstrap, i.e., just plain CSS. If it exists, what's the canonical way of styling an app?

A good example of this is the Elm-SPA example from Feldman: the Main.elm file is basically just glue code for the rest of the project (https://github.com/rtfeldman/elm-spa-example/blob/master/src/Main.elm).

After all that I've managed to reach my goal of being able to run Richard Feldman's Elm SPA Example in my system! 😃 Here's a working implementation compiled to WebAssembly. And for comparison, you can also check out the same code compiled to JavaScript. (Unfortunately the publicly available APIs don't seem to be returning very much data at the moment but there's not much I can do about that!)

Looking at the Real World application I could see that there were better ways to structure my modules using nested TEAs and keeping the Main module as a hub for everything in the app.

If you want to see Elm code, you might look for example projects on GitHub. (https://github.com/rtfeldman/elm-spa-example comes to mind.)

https://github.com/rtfeldman/elm-spa-example is a good example app. I'd also recommend https://codebase.show/projects/realworld in general if you're looking for example apps in various frameworks and languages. I sadly can't share anything from work as it's all private.

- How to properly structure the project. I differentiate between my core utils and the actual gui. Iced states in the documentation that it's inspired by the Elm architecture. So naturally I've read a little bit about the proposed Elm project structure. So I basically end in a structure like this spa example directory recommended by the Elm communicty: Repo

Ableton ⬩ Acima ⬩ ACKO ⬩ ActiveState ⬩ Adrima ⬩ AJR International ⬩ Alma ⬩ Astrosat ⬩ Ava ⬩ Avetta ⬩ Azara ⬩ Barmenia ⬩ Basiq ⬩ Beautiful Destinations ⬩ BEC Systems ⬩ Bekk ⬩ Bellroy ⬩ Bendyworks ⬩ Bernoulli Finance ⬩ Blue Fog Training ⬩ BravoTran ⬩ Brilliant ⬩ Budapest School ⬩ Buildr ⬩ Cachix ⬩ CalculoJuridico ⬩ CareRev ⬩ CARFAX ⬩ Caribou ⬩ carwow ⬩ CBANC ⬩ CircuitHub ⬩ CN Group CZ ⬩ CoinTracking ⬩ Concourse CI ⬩ Consensys ⬩ Cornell Tech ⬩ Corvus ⬩ Crowdstrike ⬩ Culture Amp ⬩ Day One ⬩ Deepgram ⬩ diesdas.digital ⬩ Dividat ⬩ Driebit ⬩ Drip ⬩ Emirates ⬩ eSpark ⬩ EXR ⬩ Featurespace ⬩ Field 33 ⬩ Fission ⬩ Flint ⬩ Folq ⬩ Ford ⬩ Forsikring ⬩ Foxhound Systems ⬩ Futurice ⬩ FörsäkringsGirot ⬩ Generative ⬩ Genesys ⬩ Geora ⬩ Gizra ⬩ GWI ⬩ HAMBS ⬩ Hatch ⬩ Hearken ⬩ hello RSE ⬩ HubTran ⬩ IBM ⬩ Idein ⬩ Illuminate ⬩ Improbable ⬩ Innovation through understanding ⬩ Insurello ⬩ iwantmyname ⬩ jambit ⬩ Jobvite ⬩ KOVnet ⬩ Kulkul ⬩ Logistically ⬩ Luko ⬩ Metronome Growth Systems ⬩ Microsoft ⬩ MidwayUSA ⬩ Mimo ⬩ Mind Gym ⬩ MindGym ⬩ Next DLP ⬩ NLX ⬩ Nomalab ⬩ Nomi ⬩ NoRedInk ⬩ Novabench ⬩ NZ Herald ⬩ Permutive ⬩ Phrase ⬩ PINATA ⬩ PinMeTo ⬩ Pivotal Tracker ⬩ PowerReviews ⬩ Practle ⬩ Prima ⬩ Rakuten ⬩ Roompact ⬩ SAVR ⬩ Scoville ⬩ Scrive ⬩ Scrivito ⬩ Serenytics ⬩ Smallbrooks ⬩ Snapview ⬩ SoPost ⬩ Splink ⬩ Spottt ⬩ Stax ⬩ Stowga ⬩ StructionSite ⬩ Studyplus For School ⬩ Symbaloo ⬩ Talend ⬩ Tallink & Silja Line ⬩ Test Double ⬩ thoughtbot ⬩ Travel Perk ⬩ TruQu ⬩ TWave ⬩ Tyler ⬩ Uncover ⬩ Unison ⬩ Veeva ⬩ Vendr ⬩ Verity ⬩ Vnator ⬩ Vy ⬩ W&W Interaction Solutions ⬩ Watermark ⬩ Webbhuset ⬩ Wejoinin ⬩ Zalora ⬩ ZEIT.IO ⬩ Zettle

> Why bother, when Dagger caches everything automatically?

The fear with needing to run `npm ci` (or better, `pnpm install`) before running dagger is on the amount of time required to get this step to run. Sure, in the early days, trying out toy examples, when the only dependencies are from dagger upstream, very little time at all. But what happens when I start pulling more and more dependencies from the Node ecosystem to build the Dagger pipeline? Your documentation includes examples like pulling in `@google-cloud/run` as a dependency: https://docs.dagger.io/620941/github-google-cloud#step-3-cre... and similar for Azure: https://docs.dagger.io/620301/azure-pipelines-container-inst... . The more dependencies brought in - the longer `npm ci` is going to take on GitHub Actions. And it's pretty predictable that, in a complicated pipeline, the list of dependencies is going to get pretty big - at least a dependency per infrastructure provider we use, plus inevitably all the random Node dependencies that work their way into any Node project, like eslint, dotenv, prettier, testing dependencies... I think I have a reasonable fear that `npm ci` just for the Dagger pipeline will hit multiple minutes, and then developers who expect linting and similar short-run jobs to finish within 30 seconds are going to wonder why they're dealing with this overhead.

It's worth noting that one of Concourse's problems was, even with webhooks setup for GitHub to notify Concourse to begin a build, Concourse's design required it to dump the contents of the webhook and query the GitHub API for the same information (whether there were new commits) before starting a pipeline and cloning the repository (see: https://github.com/concourse/concourse/issues/2240 ). And that was for a CI/CD system where, for all YAML's faults, for sure one of its strengths is that it doesn't require running `npm ci`, with all its associated slowness. So please take it on faith that, if even a relatively small source of latency like that was felt in Concourse, for sure the latency from running `npm ci` will be felt, and Dagger's users (DevOps) will be put in an uncomfortable place where they need to defend the choice of Dagger from their users (developers) who go home and build a toy example on AlternateCI which runs what they need much faster.

> I will concede that Dagger’s clustering capabilities are not great yet

Herein my argument. It's not that I'm not convinced that building pipelines in a general-purpose programming language is a better approach compared to YAML, it's that building pipelines is tightly coupled with the infrastructure that runs the pipelines. One aspect of that is scaling up compute to meet the requirements dictated by the pipeline. But another aspect is that `npm ci` should not be run before submitting the pipeline code to Dagger, but after submitting the pipeline code to Dagger. Dagger should be responsible for running `npm ci`, just like Concourse was responsible for doing all the interpolation of the `((var))` syntax (i.e. you didn't need to run some kind of templating before submitting the YAML to Concourse). If Dagger is responsible for running `npm ci` (really, `pnpm install`), then it can maintain its own local pnpm store / pipeline dependency caching, which would be much faster, and overcome any shortcomings in the caching system of GitHub Actions or whatever else is triggering it.

> Imagine you live in a world where no part of the build has to repeat unless the changes actually impacted it. A world in which all builds happened with automatic parallelism. A world in which you could reproduce very reliably any part of the build on your laptop.

That sounds similar to https://concourse-ci.org/

I quite like it, but it never seemed to gain traction outside of Cloud Foundry.

I used Concourse[0] for a while. No real complaints, the visibility is nice but the functionality isn't anything new.

[0] https://concourse-ci.org/

We run https://concourse-ci.org/ on our own hardware at our office. (as a side note, running your own hardware, you realise just how abysmally slow most cloud servers are.)

Concourse: https://concourse-ci.org

We use https://concourse-ci.org/ at the moment and have been reasonably happy with it, however it only has support for linux containers at the moment, no windows containers. (MacOS doesn't have a containers primitive yet unfortunately)