Mood Tracker Tutorial

Source for the Ema tutorial: https://ema.srid.ca/tutorial

Getting Started

To develop with full IDE support in Visual Studio Code, follow these steps:

• Install Nix & enable Flakes
• Setup the garnix cache (Nix binary cache). This is optional if you are okay with compiling for hours.
• Run nix-shell --run haskell-language-server to sanity check your environment
• Open the repository as single-folder workspace in Visual Studio Code
  • Install the recommended extensions
  • Ctrl+Shift+P to run the command "Nix-Env: Select Environment" and select shell.nix. The extension will ask you to reload VSCode at the end.
• Press Ctrl+Shift+B in VSCode, or run bin/run in terminal, to launch the Ema dev server, and navigate to http://localhost:9001/

All but the final step need to be done only once. Check the Ema tutorial next.

Note

• We are using GHC 9.2 which is not yet the default in nixpkgs, so you may want to use the garnix cache to avoid long compilation.
• This project uses relude as its prelude, as well as Tailwind+Blaze as CSS utility and HTML DSL. Even though the author highly recommends them, you are of course free to swap them out for the library of your choice.
  • Tailwind CSS is compiled, alongside Ghcid, via foreman (see ./Procfile)
• As a first step to using this template,
  • change the project name in .cabal, flake.nix and hie.yaml files; then commit changes to Git.
    • To automate this, mv MoodTracker-Tutorial.cabal myproject.cabal; nix run nixpkgs#sd -- MoodTracker-Tutorial myproject * */* .github/*/*
• Configuration:
  • To change the port (or the Ema CLI arguments, used by bin/run), see ./.ghcid (if you leave out --port a random port will be used)
  • To update Ema to the latest Git revision, run nix flake lock --update-input ema or just nix flake update (the latter updates all Nix inputs)
    • Be sure to check https://ema.srid.ca/guide/upgrade for changes needed.
  • To add/remove Haskell dependencies, see the .cabal file. If a dependency is unavailable in nixpkgs, you can override it (to point to say a Git repo) in the source-overrides (or overrides if you need more power) attribute of flake.nix. You can imitate the manner in which the ema package itself is overridden.
• To generate the site, run:

  mkdir ../output 
  nix run . -- gen ../output

  • You might want to change or remove the <base> tag in Main.hs depending on where you will be deploying the site.

Non-Nix workflow

To use this repository without Nix, such as with plain Cabal or Stack, you need to have the following installed manually:

• ghcid (used by bin/run-haskell which ./Procfile invokes)
• tailwind runner along with tailwind CLI
• foreman (or one of its rewrites)

Once all the above are installed, run foreman start to start the Ema live server.