Prism is an expressive web framework with a speed of light. Features:

• ⚡️ Efficiency based on Crystal performance
• ✨ Expressiveness with powerful DSL and lesser code
• 💼 Safety with strictly typed params

Installation

Add this to your application's shard.yml:

dependencies:
  prism:
    github: vladfaust/prism
    version: ~> 0.3.0

This shard follows Semantic Versioning v2.0.0, so check releases and change the version accordingly.

Basic example

Please refer to the API documentation available online at github.vladfaust.com/prism.

require "prism"

struct KnockKnock < Prism::Action
  include Params

  params do
    param :who, String
    param :times, Int32, validate: {max: 10}
  end

  def call
    params[:times].times do
      text("Knock-knock #{who}\n")
    end
  end
end

router = Prism::Router.new do
  get "/:who", KnockKnock
end

logger = Logger.new(STDOUT)
log_handler = Prism::LogHandler.new(logger)
handlers = [log_handler, router]

server = Prism::Server.new(handlers, logger)
server.bind_tcp(5000)
server.listen

#  INFO -- :   Prism::Server is listening on http://127.0.0.1:5000...

Websockets example

We call them Channels for convenience.

require "prism"

class Notifications < Prism::Channel
  @@subscriptions = Array(self).new

  def self.notify(message)
    @@subscriptions.each &.socket.send(message)
  end

  def on_open
    socket.send("Hello")
    @@subscriptions.push(self)
  end

  def on_close
    @@subscriptions.delete(self)
  end
end

router = Prism::Router.new do
  ws "/notifications" do |socket, env|
    Notifications.subscribe(socket, env)
  end
end

# Later in the code...

Notifications.notify("Something happened!") # Will notify all subscribers binded to this particular Crystal process

Contributing

1. Fork it ( https://github.com/vladfaust/prism/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• @vladfaust Vlad Faust - creator, maintainer