Template Project For haskell.nix and reflexfrp

This template project acts as a reference for anyone wanting to create an app that:

• Has a frontend communicating with a backend.
• Is able to cross-compile the frontend to a GTK application or a javascript application. (iOS and Android coming up).
• Uses Haskell for the frontend and the backend.
• Uses Warp to serve HTTP requests on the backend.
• Shares an API specification between the backend and the frontend using servant.
• Uses functional reactive programming on the frontend.
• Where the backend communicates with a Postgresql database.
• Uses nix to provide all the needed tools and packages.
• Defines CSS in Haskell.

The application itself is a very crude TODO list application which stores the list inside a Postgresql database. To get a desktop application, run:

nix-shell
cabal run backend-exe &
cabal run frontend-generatecss
cabal run frontend-externalcss

To quit the app, issue a Ctrl-C then fg then Ctrl-C.

To generate javascript code for the frontend, run:

cabal build --cabal-file=cabal.ghcjs.project --ghcjs frontend-externalcss

Then open the main.html file.

Use the template

This template uses copier, see the FAQ for why.

copier gh:ibizaman/hs-template-haskellnix-frp myproject

Later, to update your project based on new stuff in this template:

cd myproject && copier update

Links

• Building instructions
• IDE integration
• FAQ

Check all the documentation at docs/.

WIP

• Uses a template renderer to create new projects.
• Accept arguments for backend.
• Have github actions to build and test.
• Accept config file for backend.
• Allow frontend to setup backend endpoint through UI.
• Serve the javascript frontend from the backend.
• Add CSS for the frontend.
• Nix provides ghcjs.
• Cross-compile frontend to iOS.
• Cross-compile frontend to Android.
• ?