Building a RESTful API with Crystal

main.cr

require "http/server"

class Users::Me
  include HTTP::Handler

  def call(context)
    return call_next(context) unless match?(context.request)

    STDOUT.puts "getting user info..."
    STDOUT.puts "done!"
  end

  def match?(request : HTTP::Request)
    request.resource == "/users/me" && request.method == "GET"
  end
end

class Users::Create
  include HTTP::Handler

  def call(context)
    return call_next(context) unless match?(context.request)

    STDOUT.puts "creating user..."
    STDOUT.puts "done!"
  end

  def match?(request : HTTP::Request)
    request.resource == "/users" && request.method == "POST"
  end
end

class Users::Update
  include HTTP::Handler

  def call(context)
    return call_next(context) unless match?(context.request)

    STDOUT.puts "updating user..."
    STDOUT.puts "done!"
  end

  def match?(request : HTTP::Request)
    request.resource == "/users" && request.method == "PUT"
  end
end

class Users::UpdatePartially
  include HTTP::Handler

  def call(context)
    return call_next(context) unless match?(context.request)

    STDOUT.puts "updating user partially..."
    STDOUT.puts "done!"
  end

  def match?(request : HTTP::Request)
    request.resource == "/users" && request.method == "PUT"
  end
end

class Users::Destroy
  include HTTP::Handler

  def call(context)
    return call_next(context) unless match?(context.request)

    STDOUT.puts "destroying user..."
    STDOUT.puts "done!"
  end

  def match?(request : HTTP::Request)
    request.resource == "/users" && request.method == "DELETE"
  end
end

HTTP::Server.new("127.0.0.1", 8080, [
  HTTP::LogHandler.new,
  Users::Me.new,
  Users::Create.new,
  Users::Update.new,
  Users::UpdatePartially.new,
  Users::Destroy.new,
]).listen