reflex-frp is a functional reactive programming framework for Haskell.
- see reflex-platform notes on os-compatibility
- also, it works on Ubuntu and should work on any Linux
- for any OS except NixOS you'll need Nix package manager
- single user installation is the simplest thing that will work, but for experience closer to NixOS you may want to use multi-user installation
If you use NixOS, you may want to add binary cache; for any other OS the same can be done for Nix package manager by adding to /etc/nix/nix.conf the following:
substituters = https://cache.nixos.org https://nixcache.reflex-frp.org
trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= ryantrinkle.com-1:JJiAKaRv9mWgpVAz8dwewnZe0AzzEAzPkagE9SP5NWI=
binary-caches = https://cache.nixos.org https://nixcache.reflex-frp.org
binary-cache-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= ryantrinkle.com-1:JJiAKaRv9mWgpVAz8dwewnZe0AzzEAzPkagE9SP5NWI=
binary-caches-parallel-connections = 40
- An introduction to reflex by Queensland FP Lab
- reflex-dom-inbits
- Reflex docs
- Reflex Quick(ish) Reference
- Reflex-Dom Quick(ish) Reference
- clone template to desired dir and cd there
rm -rf .git && git init- update:
- LICENSE (at least, replace
<name>) - frontend/LICENSE (at least, replace
<name>) - frontend.cabal (replace
<name>,<email>) - bin/open-page-cabal and bin/run-cabal (fix paths)
- TODO: is there a way to detect these paths from shell automatically?
- LICENSE (at least, replace
- optional:
- configure tools:
stylish-haskell -d > .stylish-haskell.yamland update the filehlint -d > .hlint.yamland update the file
- update
reflex-platform - if you don't use Visual Studio Code:
rm -rf .vscode - rename
frontendpackage:- in frontend.cabal change
nameandexecutableas desired - in bin/open-page change
frontend.jsexeto proper name - in bin/run change
frontendfile name to your executable name - in bin/open-page-cabal and bin/run-cabal fix paths
- in frontend.cabal change
- recreate
frontendpackage completely:bin/shell(since you'll needcabalto create package)rm -rf frontend- add new package
- configure tools:
build=nix-build -o result/frontend -A ghcjs.frontendbuild-cabal=nix-shell -A shells.ghcjs --run "cabal --project-file=cabal-ghcjs.project --builddir=dist-ghcjs new-build all"build-native=nix-build -o result/frontend-native -A ghc.frontend --arg useWarp false- for warp-based version remove
--arg useWarp falsepiece
- for warp-based version remove
build-native-cabal=nix-shell -A shells.ghc --run "cabal new-build all"clean=rm -rf result dist-*ghcid=nix-shell -A shells.ghc --run 'ghcid -W -c "cabal new-repl frontend" -T Main.main'hoogle=nix-shell -A shells.ghc --run "hoogle server --local --port=8080" --arg withHoogle trueopen=xdg-open http://localhost:3003open-page=xdg-open file://`pwd`/result/frontend/bin/frontend.jsexe/index.htmlopen-page-cabal=xdg-open file://`pwd`/dist-ghcjs/build/x86_64-linux/ghcjs-8.4.0.1/frontend-0.1.0.0/x/frontend/build/frontend/frontend.jsexe/index.htmlopen-hoogle=xdg-open http://localhost:8080repl=cabal new-repl frontend(run underbin/shell)run=result/frontend-native/bin/frontendrun-cabal=dist-newstyle/build/x86_64-linux/ghc-8.4.3/frontend-0.1.0.0/x/frontend/build/frontend/frontendshell=nix-shell -A shells.ghcshelljs=nix-shell -A shells.ghcjsstyle=find frontend/src -name "*.hs" | xargs stylish-haskell -i
There are 3 ways of building project:
- GHC with jsaddle, result = web server executable (warp)
- GHC with WebKit, result = WebKit application (native)
- still uses jsaddle under the hood to communicate with page hosted by WebKit
- GHCJS, result = JS scripts / HTML page
There are also options for building iOS/Android apps, but they aren't included into this template.
Usually you use warp way for development (with bin/ghcid) because it recompiles and reloads the app automatically. So, for development you do:
- open terminal for each of:
bin/hooglebin/ghcidbin/shell
- run
bin/opento open warp url in browser - run your favorite editor under
bin/shell(e.g.code .) - optional:
- run
bin/replunderbin/shell
- run
Your project may have JS FFI that doesn't have jsaddle implementation. Good example is a browser extension API which is not available for the code running on a regular HTML page. In this case you cannot use GHC. You cannot use ghcid as well because GHCJS doesn't support interactive mode yet. You still can build JS with bin/build, but it uses Nix and cannot build incrementally. Instead you may want to use:
bin/build-cabalto build with cabal and GHCJSbin/open-page-cabalto open HTML page created by the build
- run
bin/build - see result in
result/frontend/bin/frontend.jsexe- use
bin/open-pageto open it
- use
native:
- run
bin/build-native - see result in
result/frontend-native/bin- use
bin/runto run it
- use
bin/clean- remove all build resultsbin/style- run stylish-haskell (run underbin/shell)- WARN: updates files in place, use with care!
- it's recommended to commit the changes first, then run
bin/styleand make sure you like the diff
- open reflex-platform and find commit you want
nix-prefetch-git https://github.com/reflex-frp/reflex-platform.gitcommit- use
revandsha256from output to update nix/reflex-platform.nix
bin/shell(if not under it already)mkdirpackagecdpackagecabal init- add
reflex-domto cabal filebuild-dependssection if needed - add package to cabal.project
- add package to default.nix sections
packagesandshells - add package src dir to .vscode/settings.json under
ghcSimple.startupCommands.customitem that starts with:set -i- paths are separated by
:like-ifrontend/src:somepkg/src
- paths are separated by
- update bin/style
This template is based on:
- Exploring Nix & Haskell Part 3: Less Nix, More Reflex article
- the code is in haskell-nix-skeleton-2
- which is based on reflex-project-skeleton
- which uses reflex-platform
- which is based on reflex-project-skeleton
- the code is in haskell-nix-skeleton-2
License is MIT