websocketCollab

Collaborative system for editing text backend made on Go. This project was made to learn Fiber framework and websockets.

Stack

I used following technologies:

• Go as programming language
• Fiber as web framework
• SQLite (or Postgres in Docker) as DB
• Websockets
• Docker

Run project

You can run project with docker or without it

Running project in Docker

To run project in Docker:

1. Uncomment PostgreSQL connection string in cmd/websocketCollabServer/main.go, and comment SQLite connection string:

// this connection can be used to connect to postgres inside docker container.
// db, err := gorm.Open(postgres.Open(getDsn()), &gorm.Config{Logger: logger.Default.LogMode(logger.Info)})

// this connection uses sqlite
db, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{Logger: logger.Default.LogMode(logger.Info)})

2. Build image: docker build . -t "wscollab:latest"
3. Run docker-compose: docker-compose -f docker-compose.yaml up

Running project without Docker

To run project without docker with SQLite Database

1. Use command go mod download to install dependencies
2. Use command go run cmd/websocketCollabServer/main.go to run project

How to use it?

API of this project includes 2 endpoints:

1. POST - /api/v1/documents - will create new empty document. This request requires no parameters or body, in response you will get JSON-encoded document, which will include Id
2. GET - /api/v1/documents/{id} - websocket handshake path, connect by id of your document using any websocket client, for example https://chromewebstore.google.com/detail/simple-websocket-client/pfdhoblngboilpfeibdedpjgfnlcodoo?pli=1

How to add text?

To add text, you need to send json-encoded message with this format:

{
  "cmd": {command type here, command can be "INSERT" or "DELETE"},
  "position": {float32 here, document CRDT uses float indexing to avoid conflicts},
  "value": {byte value here, if command is "DELETE" value will be ignored}
}

After sending such message, all clients, connnected to this document will recieve edited document text as a message