Question

有没有办法清理这些# mymodel.rb has_many :friendships, -> { includes :friend } has_many :friends, -> { where(friendships: { status: 'accepted'}) }, through: :friendships, :source => :friend has_many :requests, -> { where(friendships: { status: 'requested'}) }, through: :friendships, :source => :friend has_many :requested_friendships, -> { where(friendships: { status: 'requestor'}) }, through: :friendships, :source => :friend关系，他们看起来很残酷。我可以把它们放在一个街区或以任何方式干掉它们吗？

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Answer 1

一个方便的方法是with_options，它允许您将相同的选项应用于一系列方法调用。您可以这样使用它：

has_many :friendships, -> { includes :friend }

with_options through: :friendships, source: :friend do |model|
  model.has_many :friends, -> { where(friendships: { status: 'accepted' }) }
  model.has_many :requests, -> { where(friendships: { status: 'requested' }) }
  model.has_many :requested_friendships, -> { where(friendships: { status: 'requestor' }) }
end

我觉得这很不错。如果您愿意，可以使用范围增强它：

has_many :friendships, -> { includes :friend }

with_options through: :friendships, source: :friend do |model|
  model.has_many :friends, -> { with_friendship_status 'accepted' }
  model.has_many :requests, -> { with_friendship_status 'requested' }
  model.has_many :requested_friendships, -> { with_friendship_status 'requestor' }
end

scope :with_friendship_status, ->(status) { where(friendships: { status: status }) }

或者，您可以这样做：

has_many :friendships, -> { includes :friend }

{ friends: "accepted",
  requests: "requested",
  requested_friendships: "requestor"
}.each do |assoc, status|
  has_many assoc, -> { where(friendships: { status: status }) },
    through: :friendships, source: :friend
end

...但我觉得你在没有太多收获的情况下会失去很多可读性。

是否有更清洁或更短的方式来显示这些has_many关系？

1 个答案: