h42n42

Project that aims to make you discover the basis of web programming on the client side in OCaml thanks to Ocsigen

Hopefully, this project will be opened to other programming languages in the future. Until then, here are all my notes that might be helpfull to get started with Eliom (OCaml).

Mac

Install

brew install opam sqlite
opam init
opam install dune utop ocamlformat sqlite3 ocsipersist-sqlite eliom js_of_ocaml-lwt

Uninstall

brew uninstall --zap opam sqlite
# Remove opam switches
rm -rf ~/.opam

Ubuntu at 42

Install

brew install opam sqlite openssl@1.1 pcre

# `disable-sandboxing` and `export` are necessary because brew
# is not installed at root level at school. Without those modifications
# `opam` won't be able to find brew's sqlite, for example
opam init --disable-sandboxing
# add to ~/.zshrc
export LD_LIBRARY_PATH=/usr/local/lib:$HOME/.brew/lib

# To prevent opam for promting user to install libsqlite3-dev with apt
# because you don't have sudo access, so it will proceed and try to use
# the one from brew
opam option depext-bypass=libsqlite3-dev

opam install dune utop ocamlformat sqlite3 ocsipersist-sqlite eliom js_of_ocaml-lwt

Uninstall

brew uninstall --zap opam sqlite openssl@1.1 pcre
# Remove opam switches
rm -rf ~/.opam

---

Run

# Compile & run. The site is accessible at http://localhost:8080/
make test.opt

# To be able to run `make test.byte` change in `Makefile`
OCSIGENSERVER := DYLD_LIBRARY_PATH=$(shell opam var lib)/stublibs ocsigenserver

Notes

• Eliom is not fully supported by vscode OCaml extension and ocaml-lsp-server (don’t install it to avoid errors showing up everywhere), so you’ll have only syntax highlighting in your editor.
• Eliom doesn’t automatically rebuild and relaunch when you make changes to a file. So for ease of use, I created a vscode build task (in .vscode/tasks.json) to rapidly do that with a single shortcut cmd+shift+B on Mac (ctrl+shift+B on Ubuntu). It automatically terminates all running tasks, autoformats all *.eliom files, then builds and launches the server. Feel free to use it, it helped me a lot.
• Launch ./autoformat.sh to automatically format all *.eliom files if you don’t want to use the above build task.

⚠️ For autoformat to work make sure your project have a .ocamlformat file (empty or with explicite arguments)

---

(* Log string *)
print_endline (Js.to_string playground##.className);
(* Log anything *)
Js_of_ocaml.Firebug.console##log (Js.string "OK");

# Clean opam cache
opam clean --all

# Uninstall + remove dependances
opam remove <list of packages> --auto-remove