bigdir/app/models/project_info.rb

class ProjectInfo < ActiveRecord::Base
  attr_accessible :project_id, :user_id

  belongs_to :project
  belongs_to :user
  validates_presence_of :project_id, :user_id
  validates_uniqueness_of :project_id, :scope => :user_id
  
  def self.manager? (user_id, project)
    for project_info in project.project_infos
      if project_info.user_id == user_id
      return true
      end
    end
    return false
  end
end