class Decidim::Meetings::JoinMeeting

This command is executed when the user joins a meeting.

def accept_invitation 

def accept_invitation
  meeting.invites.find_by(user: user)&.accept!
end

def call

Broadcasts :ok if successful, :invalid otherwise.

and there are available slots.
Creates a meeting registration if the meeting has registrations enabled 
def call
  meeting.with_lock do
    return broadcast(:invalid) unless can_join_meeting?
    create_registration
    accept_invitation
    send_email_confirmation
    send_notification
    increment_score
  end
  broadcast(:ok)
end

def can_join_meeting? 

def can_join_meeting?
  meeting.registrations_enabled? && meeting.has_available_slots?
end

def create_registration 

def create_registration
  @registration = Decidim::Meetings::Registration.create!(meeting: meeting, user: user)
end

def increment_score 

def increment_score
  Decidim::Gamification.increment_score(user, :attended_meetings)
end

def initialize(meeting, user)

user - The user joining the meeting.
meeting - The current instance of the meeting to be joined.

Initializes a JoinMeeting Command. 
def initialize(meeting, user)
  @meeting = meeting
  @user = user
end

def occupied_slots_over?(percentage) 

def occupied_slots_over?(percentage)
  @meeting.remaining_slots == (@meeting.available_slots * (1 - percentage)).round
end

def participatory_space_admins 

def participatory_space_admins
  @meeting.component.participatory_space.admins
end

def send_email_confirmation 

def send_email_confirmation
  Decidim::Meetings::RegistrationMailer.confirmation(user, meeting, registration).deliver_later
end

def send_notification 

def send_notification
  return send_notification_over(0.5) if occupied_slots_over?(0.5)
  return send_notification_over(0.8) if occupied_slots_over?(0.8)
  send_notification_over(1.0) if occupied_slots_over?(1.0)
end

def send_notification_over(percentage) 

def send_notification_over(percentage)
  Decidim::EventsManager.publish(
    event: "decidim.events.meetings.meeting_registrations_over_percentage",
    event_class: Decidim::Meetings::MeetingRegistrationsOverPercentageEvent,
    resource: @meeting,
    recipient_ids: participatory_space_admins.pluck(:id),
    extra: {
      percentage: percentage
    }
  )
end