Programming language: Crystal
Tags: Examples And Funny Stuff    

kemal-react-pg-chat alternatives and similar shards

Based on the "Examples and funny stuff" category

Do you think we are missing an alternative of kemal-react-pg-chat or a related project?

Add another 'Examples and funny stuff' Shard


React + ES2015 + Kemal + PostgreSQL Chat Example


Chat app using React + ES2015 + Kemal + PostgreSQL

This demonstrates how easy it is to build Realtime Web applications with Kemal.

* This project is a fork of https://github.com/f/kemal-react-chat, but implements ES2015 and integrates with a persistent data storage with PostgreSQL*


  • Crystal 0.18.7
  • PostgreSQL (I have the v9.5.2)
  • Node (I have the v5.11.1)
  • NPM (I have the v3.8.6)

*Node and NPM are both optional if you are just going to run the app, but necessary for development since they are needed to run the gulp tasks


Before you can run this program you have to install the packages that it uses. You do that with $ shards install. You also need to change the path to the PostgreSQL database in src/db/init_db.cr and src/app.cr

# src/db/init_db.cr
require "pg"

# Configure these two variables
DB_NAME = "db_name"
PG_PATH = "postgres://user:password@localhost:5432"

# src/notes.cr
require "kemal"
require "pg"
require "./app/message"

# Configure the path of the database based on what you did in the src/db/init_db.cr file
conn = PG.connect "postgres://user:password@localhost:5432/db_name


Once you have installed the dependencies and configured the database path, you need to create the actual database and table for the application. You do that by running $ crystal src/db/init_db.cr.

Run Project

You can run this program in two ways:

  1. Compile/build the project using the command line with $ crystal build src/app.cr --release and run the executable $ ./app
  2. Run the program with $ crystal src/app.cr (no compilation required)

Once you have run the program, you can open a browser window at localthost:3000 and see the actual app.

Live Demo

You can see and use a live demo of the app here: kemal-react-pg-chat.herokuapp.com.