模型方法触发布尔值为真？

Question

如何在days_left_challenged == 0 上触发方法accomplished_challenge？

挑战.rb

  before_save :days_left_challenged_sets_deadline

  # makes ongoing_challenge become past (before_save) THIS WORKS
  def days_left_challenged_sets_deadline
    if self.date_started != nil 
      if days_left_challenged <= 0
        self.accomplished = true
        self.deadline = self.date_started
      end
    end
  end

  # makes ongoing_challenge become past (whenever gem) THIS DOESN'T
  def self.accomplished_challenge
    self.all.each do |challenge|
      if challenge.days_left_challenged <= 0
        challenge.accomplished = true
        challenge.deadline = self.date_started
      end
    end
  end

 # Counts down how many days left in days_challenged using committed
 def days_left_challenged
   self.days_challenged - ((date_started.to_date)..Date.yesterday).count do |date| 
     committed_wdays.include? date.wday
   end + self.missed_days
 end

挑战.last

 id: 1,
 action: "Run",
 committed: ["sun", "mon", "tue", "wed", "thu", "fri", "sat", ""],
 date_started: Sat, 06 Feb 2016 00:00:00 EST -05:00,
 deadline: nil,
 accomplished: nil,
 days_challenged: 10,
 missed_days: 0,

我无法通过回调或验证来触发它，因为days_left_challenged 可以在挑战的任何时候转向0。

Answer 1

我建议您使用像 Whenever 这样的 gem 来设置一个每天运行的 cron 作业，并检查所有挑战。它会是这样的：

every 1.day, :at => '0:01 am' do
  runner "Challenge.accomplished_challenge"
end

您的accomplished_challenge 必须是一个类方法，可以检查所有（或您使用过滤器选择的）挑战：

def self.accomplished_challenge
  self.all.each do |challenge|
    if challenge.days_left_challenged == 0
      challenge.update_attributes(deadline: self.date_started, accomplished: true)         
    end
  end
end

---- 编辑 Heroku ----

在/lib/tasks/scheduler.rake上创建一个任务：

# /lib/tasks/scheduler.rake

desc "This task is called by the Heroku scheduler add-on"
task :check_accomplished_challenges => :environment do
  puts "Checking accomplished challenges..."
  Challenge.accomplished_challenge
  puts "done."
end

转到您的 Heroku 应用资源页面并添加“Heroku 调度程序”。打开调度器并添加任务：

rake check_accomplished_challenges

将其设置为每天运行。 更多详情：https://devcenter.heroku.com/articles/scheduler