为什么我不能从类封装的方法中访问下面代码中的check_url私有方法？
class Link < MyModel
# whitelist fields for security
attr_accessible :is_valid,:url
# validations
validates :is_valid,:inclusion => { :in => [true,false] }
validates :url,:presence => true
# ===============================================================
# = class methods (accessible from outside without an instance) =
# ===============================================================
class << self
def is_url_valid(url)
unless link = Link.find_by_url(url)
link = Link.create!(:url => url,:is_valid => check_url(url))
end
link.is_valid
end
end
# =====================
# = Private functions =
# =====================
private
# Checks if url is broken
def check_url(url)
# do stuff
end
end
PS.我也尝试过使用self.check_url但它没有用.
解决方法
在Ruby中,不能使用显式接收器调用私有方法.所以你不能打电话给self.check_url.相反,只需调用check_url.
您的另一个问题是您将check_url定义为实例方法,并在类方法中调用它.将check_url移动到类<<自我范围：
class << self
def is_url_valid(url)
unless link = Link.find_by_url(url)
link = Link.create!(:url => url,:is_valid => check_url(url))
end
link.is_valid
end
private
# Checks if url is broken
def check_url(url)
# do stuff
end
end