Question

我是一个新手创建我的第一个应用程序，一些红宝石爱好者告诉我，我的编码方式无效。因为要达到一个干净的状态需要做很多工作，所以我想确保做对我更好的事情。

在下面的代码中，您认为我过度使用has_many方法，如果是，我应该如何替换它？

class Product < ActiveRecord::Base

  # Offerers
  has_many :ownerships, dependent: :destroy 
  has_many :owners, through: :ownerships,
                      source: :offerer

  # Seekers
  has_many :loans, dependent: :destroy
  has_many :borrowers, through: :loans,
                     source: :seeker



  # Owners
  has_many :previous_ownerships, -> { where 'owning_date IS NOT NULL AND giving_date IS NOT NULL', agreed: true },
                                 class_name: 'Ownership'
  has_one :current_ownership, -> { where current: true, agreed: true },
                             class_name: 'Ownership'
  has_many :next_ownerships, -> { where owning_date: nil, giving_date: nil },
                             class_name: 'Ownership'

  has_many :previous_owners, through: :previous_ownerships,
                             source: :offerer
  has_one :owner, through: :current_ownership,
                  source: :offerer
  has_many :next_owners, through: :next_ownerships,
                         source: :offerer


  # Borrowers
  has_many :previous_loans, -> { where 'return_date IS NOT NULL AND borrowing_date IS NOT NULL', agreed: true },
                            class_name: 'Loan'
  has_one :current_loan, -> { where current: true, agreed: true },
                               class_name: 'Loan'
  has_many :next_loans, -> { where borrowing_date: nil, return_date: nil },
                                  class_name: 'Loan'

  has_many :previous_borrowers, through: :previous_loans,
                                source: :seeker
  has_many :next_borrowers, through: :next_loans,
                            source: :seeker
  has_one :borrower, through: :current_loan,
                              source: :seeker

 # Agreed or refused owners
  has_many :agreed_ownerships, -> { where agreed: true, owning_date: nil, giving_date: nil },
                                 class_name: 'Ownership'
  has_many :possible_ownerships, -> { where agreed: nil, owning_date: nil, giving_date: nil },
                                 class_name: 'Ownership'
  has_many :refused_ownerships, -> { where agreed: false, owning_date: nil, giving_date: nil },
                                 class_name: 'Ownership'
  has_many :agreed_owners, through: :agreed_ownerships,
                             source: :offerer
  has_many :possible_owners, through: :possible_ownerships,
                             source: :offerer
  has_many :refused_owners, through: :refused_ownerships,
                             source: :offerer

  # Agreed or refused borrowers
  has_many :agreed_loans, -> { where agreed: true, borrowing_date: nil, return_date: nil },
                                 class_name: 'Loan'
  has_many :possible_loans, -> { where agreed: nil, borrowing_date: nil, return_date: nil },
                                 class_name: 'Loan'
  has_many :refused_loans, -> { where agreed: false, borrowing_date: nil, return_date: nil },
                                 class_name: 'Loan'
  has_many :agreed_borrowers, through: :agreed_loans,
                             source: :seeker
  has_many :possible_borrowers, through: :possible_loans,
                             source: :seeker
  has_many :refused_borrowers, through: :refused_loans,
                             source: :seeker

Answer 1

在许多地方，您使用的是has_many，就像它是一个范围一样。

阅读范围here。

范围允许您定义一个可以像方法一样访问的查询。例如：

class Loan < ActiveRecord::Base
  scope :current, where(current: true, agreed: true)
end

可以像这样调用：Product.first.loans.current

确保您也将这些范围放在适当的模型中，例如，您不想在产品模型中过滤贷款。

Rails最佳实践 - 我可以使用很多“有很多”吗？

1 个答案: