Rescript Relay Sandbox

This repo is a port of the Forum software and schema from https://github.com/graphile/examples

Stack

Our stack consists of the following technologies:

• PostgreSQL >=14: Used as our datastore and for backend functions
• Postgraphile CLI: Used to introspect a Postgres schema and serve a GraphQL API
• React + Relay: Frontend libraries for building user interfaces and managing API data (developed by Facebook)
• Rescript: A type-inferred functional programming language that commpiles to JavaScript (again, Facebook tech)
• rescript-relay: An addition to the Relay compiler that emits types, adds a preprocessor (ppx) to your source, and supports a VSCode plugin.

Prerequisites

Before you begin, ensure you have the following set up:

• Node.js >=18.6: Used as a runtime environment for executing JavaScript
• PostgreSQL >=14: A recent and running instance, likely on localhost, which Postgraphile can connect to using a connection string.
• VSCode: For coding and utilizing plugins for Rescript, rescript-relay, and Relay.
• Yarn: To manage package dependencies
• Watchman: A file watching service developed by Facebook, which is necessary for Relay.
• Environment Variables: DATABASE_URL for Postgres connection.

In case any of these tools are not installed, here are some quick setup guides:

For MacOS:

First, if you haven't already, install Homebrew, a package manager for MacOS that makes it easy to install software from the command line.

1. Node.js: Download and install from Node.js's website.
2. PostgreSQL: Install with brew install postgresql@15.
3. VSCode: Download and install from VSCode's website.
4. Yarn: Install with brew install yarn.
5. Watchman: Install with brew install watchman.

For Windows:

1. Node.js: Download and install from Node.js's website.
2. PostgreSQL: Download and install from PostgreSQL's website.
3. VSCode: Download and install from VSCode's website.
4. Yarn: Download and install from Yarn's website.
5. Watchman: Download and install from Watchman's website.

Additionally, you will want to install the following VSCode extensions:

• Rescript
• Relay
• GraphQL
• rescript-relay

Setting up the project

After cloning this repository and installing the prerequisites, you can start setting up the project:

1. Create a PostgreSQL Database. Use pgsql or pgcli to run the following command:

   CREATE DATABASE relayforums;

   Note: The below connection string assumes a Postgres user named drew with password 1234. If you would like to use a different user, you will need to modify the connection string in the .env file and update the 999_data.sql file in the db directory. Either way, ensure that the user has proper privileges on the relayforums database:

   CREATE USER drew WITH PASSWORD '1234';
   ALTER USER drew WITH SUPERUSER;

2. Run bash commands.. Assuming you start in the root project directory, navigate to the db directory, populate the database, return to the root directory, install dependencies, and build the project:

   cd ./db;
   psql relayforums < ./reset.sql # or psql -f ./reset.sql -d relayforums
   cd ../
   yarn;
   mkdir ./src/__generated__;
   yarn relay:build;
   yarn re:build;

3. Create a .env file.. In the root directory, create a file called .env and add the following:

   DATABASE_URL=postgres://drew:1234@localhost/relayforums # or the Cloud SQL connection string
   GRAPHILE_URL=http://localhost:5000/graphql

4. Start the Postgraphile server.. In the root directory, run the following. Wait until the server starts up and you can see GraphiQL at the URL it provides:

    yarn postgraphile:dev

   Keep this server up and running in a terminal. Then, in a separate terminal...

5. Start the Parcel server. In the root directory, run the following command to serve your project as you develop:

   yarn parcel:serve;

   This will start a server at localhost:1234 that will automatically reload when you make changes to your code.

And that's it! You should now be able to see the Forum app running at localhost:1234 and the GraphiQL interface at localhost:5000/graphiql.