reactive.rb

def viewDidLoad
  super

  @enabled_wiretap = self.loginButton.wiretap(:enabled).bind_to(
    [
      self.usernameTextField.wiretap(:text),
      self.passwordTextField.wiretap(:text),
      LoginManager.sharedManager.wiretap(:loggingIn),
      self.wiretap(:loggedIn),
    ].wiretap.combine do |username, password, logging_in, logged_in|
      username.present? &&password.present? && !logging_in && !logged_in
    end
    )

  @touch_wiretap = self.loginButton.wiretap.on(:touch) do
    -> {
      LoginManager.sharedManager.logInWithUsername(
        self.usernameTextField.text,
        password: self.passwordTextField.text)
    }.wiretap.on_error do |error|
      presentError(error)
    end.and_then do
      loggedIn = true
    end
  end
end





self.wiretap(:name) do |new_name|
  puts "Name changed to #{new_name}"
end


name_is_valid_signal = [
  usernameField.wiretap(:text),
  passwordField.wiretap(:text),
].wiretap  # an array of signals fires whenever any element fires
  # reduced signals transform a list of values into one
  .reduce do |username, password|
    return username.length > 0 && password.length > 0 && ! username.include? ' '
  end


loginButton.wiretap(:enabled).bind_to(name_is_valid_signal)

textField.wiretap(:text).bind_to(viewModel.wiretap(:title))

scoreStepper.wiretap(:value).take(viewModel.maxPointUpdates) do |points|
  viewModel.points = points
end

uploadButton.wiretap  # returns a WiretapView
  .on(:touch)         # which can respond to gesture recognizers
  .skip(KMaxUploads - 1)
  .take(1) do
    nameField.enabled = false
    scoreStepper.hidden = true
    uploadButton.hidden = true
end



[
  self.wiretap(:password),
  self.wiretap(:passwordConfirmation),
].wiretap.reduce do |password,password_confirmation|
  return password == password_confirmation
end.and_then do |passwords_match|
  self.createEnabled = passwords_match
end



helpLabel.wiretap(:text).bind_to(
  self.wiretap(:help)
    # filtered signals only fire when the block returns true
    .filter { |new_help| !new_help.nil? }
    .map { |new_help| new_help.upcase }
    )






[
  client.fetchUserRepos,  # returns a wiretap
  client.fetchOrgRepos,  # returns a wiretap
].wiretap.and_then do
  puts "They're both done!"
end




client.loginUser  # return wiretap
  .and_then(client.loadCachedMessages)
  .and_then(client.fetchMessages)
  .and_then do
    puts "Fetched all messages"
end








-> {
  fetchUserWithUsername('colinta')
}.wiretap  # returns WiretapProc
  .queue(Dispatch::Queue.concurrent)  # the Proc will be run on this queue
  .map do |user|
    NSImage.alloc.initWithContentsOfURL(user.avatarURL)
  end
  .deliver_on(Dispatch::Queue.main)  # returns a signal that will be called on the main queue
  .and_then do |image|
    imageView.image = image
  end