haskell-elm-todo-app

Update 09/24/2019: Support of GHC 8.6.5 and Elm 0.19

Todo app build with Haskell (Servant, Persistent) on server-side and Elm on client-side.

Random notes (2016)

The modular structure of the Elm app based on the article "How I Structure Elm Apps" by Kris Jenkins. It also uses the elm-return library by Isaac Shapira for using a Writer monad approach with any update function.

It might be overkill somehow to use all these things for a simple Todo app. Anyway, I just wanted to check it out what is possible and how does it feel to write a bigger Elm application in any future...

Instructions

Server-side app

• Build:

stack build

• Execute:

stack exec haskell-elm-todo

• Run tests:

stack test

DB queries

by using httpie:

# add a todo
http POST localhost:3000/todo/ completed:=false description="my todo"

# get a todo
http localhost:3000/todo/1

# delete a todo
http DELETE localhost:3000/todo/1

# update a todo
http PUT localhost:3000/todo/1 description="any other description" completed:=true

# get all todos
http localhost:3000/todos

Client-side app

• Goto project folder

cd {project}/client/

• Build:

npm i

• Run:

npm start

Open http://localhost:3333.

Acknowledge (2016)

Helpful Haskell / Servant stuff

• Haskell + Persistent: http://www.yesodweb.com/book/persistent

• School of Haskell "Querying an existing database"

• Example Servant + Persistent: https://github.com/haskell-servant/example-servant-persistent/

• Example Servant + Persistent by Matt Parsons: https://github.com/parsonsmatt/servant-persistent

• Example Servant + Elm: https://github.com/haskell-servant/example-servant-elm

• "Todobackend" with Servant: https://github.com/jhedev/todobackend-haskell/tree/master/todobackend-servant

• Album app (Haskell + Elm) by Magnus Rundberget / @rundis: https://github.com/rundis/albums

• DB example of "5 Ways to Test Application Code that Accesses a Database in Haskell"

Helpful Elm stuff

• Blog post "How I Structure Elm Apps" by Kris Jenkins / @krisajenkins

• Advanced example of elm-dialog by Kris Jenkins / @krisajenkins

• Blog post "The Return Monad" by Isaac Shapira / @Fresheyeball

• Blog post "Optical Swordplay With Components" by Kyle J. Kress / @toastal