servant-elm-template

Description

• This is a template for using servant and elm
• This template is built with:
  • Stack -- build the haskell project
  • Postgres -- database
  • Elm -- front end
  • Webpack -- bundling tool
  • Typescript -- for frontend javascript such as embedding your elm app and ports
  • Ruby -- for database migrations and build tool
  • npm -- node package manager
• This app is just a raw skeleton to use haskell for your backend and elm for your front end.
• The example posts a dice to the server, rolls that dice, then sends back the result
• The code-generator generates your elm types, decoders, encoders, and api endpoints from your haskell types

Prerequisites

1. Install NodeJS v6.9+ choco install nodejs-lts
2. Install Elm v0.18 choco install elm-platform
3. Install Ruby choco install ruby
4. Install Postgres choco install postgresql
5. Install Stack choco install haskell-stack
6. Run stack setup stack setup
7. Install hpack stack install hpack
8. Install intero stack install intero
9. Install typescript globally npm install -g typescript
10. Run rake npm
11. Run rake elm
12. Install pg gem install pg
13. Install standalone_migrations gem install standalone_migrations

Development

• run rake watch
  • this will build your project and enable hot reloading
• IDE
  • I recommend using VS Code with the following plugins:
    • language-haskell
    • Vans.haskero
    • sbrink.elm
    • abadi199.elm-format
    • realazy.elmx
    • monofon.hindent-format
    • rebornix.ruby
    • groksrc.ruby
    • hoovercj.ruby-linter
    • mrmInc.vscode-scss
    • emmanuelbeziat.vscode-great-icons
    • joeandaverde.vscode-elm-jump
    • siegebell.prettify-symbols-mode
  • Run On Save / Hindent
    • To format your elm code on save, you need to use runonsave combined with hindent
      • monofon.hindent-format
      • emeraldwalk.runonsave
      • update your vscode settings with

            "emeraldwalk.runonsave": {
                "commands": [
                    {
                        "match": ".hs",
                        "cmd": "cd ${fileDirname} && hindent ${file}"
                    }
                ]
            } 
        

  • Elm Format on Save
    • npm install elm-format
    • update your vscode settings with "elm.formatOnSave": true

Production

• run rake build
  • this will build your app for production by generating your dist folder
• then run rake serve to serve your production app

Included Already

• JQuery
• Bootstrap
• Font Awesome
• Tether

Project Structure

• client -- all client side code
• db -- all database migrations
• server -- all server side code

Environment Variables

• POSTGRES
  • POSTGRES_HOST -- postgres host
  • POSTGRES_PORT -- postgres port
  • POSTGRES_USER -- postgres username
  • POSTGRES_PASS -- postgres password
  • POSTGRES_DATABASE -- postgres database

Postgres Database Migrations

• Creating a new migration
  • rake db_create_migration name={name}
  • this will create a new db migration in db/migrate
• Resetting your db
  • rake rebuild_db_dev
  • this will drop your database and recreate it
  • note: you need to have the correct db_name, user_name, and user_password in the config.yml for this to work
• Running the migrations
  • running your app will automatically run the postgres migrations when your servant server starts up.
  • The environment variables need to be set up or the defaults need to be set to match your postgres credentials for this to work.