Prognosticator is a web app that allows users to record arbitrary predictions that they have some opinion / conviction on, and update and track their accuracy over time.
Prognosticator also serves as a playground for me to learn Halogen and to learn about building web apps (server + client) in a purely functional way with Purescript.
Prognosticator is written in Purescript, leveraging Node.js, ExpressJS, Halogen UI framework, PostgreSQL for persistance, and cookie-stored sessions (via ExpressJS) to avoid needing a session store.
The main entry point for the node/express server is located in src/Server/Main.purs,
and the main entry point for the UI is located in src/UI/Main.purs.
Setting up your dev environment. You will need to install nix, if you don't have it already.
You will also want a PostgreSQL server available, the below suggests using docker, with the provided docker helper script.
Finally, currently Prognosticator only supports sign-in with Google,
so you will need to have a Google AppID setup in your .env for
login and authentication to work.
# To run the server, and postgres server,
# you will need the proper environment
# variables set. Copy the .env.template
# file to .env and fill in the appropriate
# values before sourcing
. .env
# Start Postgres in Docker
# You can stop, rm, and start this container
# later with these commands:
# - docker stop prognosticator-pg
# - docker rm prognosticator-pg
# - docker start prognosticator-pg
db/local_docker.sh
# Install npm deps, spago, and purescript deps
make setup
# Migrate the database up
make db-migrate-up
# Run the server
# This builds the client-side app.js
# and then runs the local server
make serve
# Now you can view it in your browser
# http://localhost:port
- Add sorting / pagination / filtering to queries
- Add ability to create forecasts on a question
- Add better error messages for Create Question / Forecast
- Add statistics for forecasts from the forecast group
- Add charts / graphs for forecasts over time
- Implement hot reloading with Parcel (https://github.com/justinwoo/halogen-parcel-hot-reload-demo)