belongs_to cache

rubyonrails-talk
1

Hello, All!

I've met the strange behavior and would like to ask the community if this is normal?

class TradingAccount < ActiveRecord::Base   belongs_to :trading_account_type end

$ rails c Loading development environment (Rails 3.0.5) irb(main):001:0> TradingAccountType.all.map(&:id) => [1, 2] irb(main):002:0> ta = TradingAccount.find 6 => #<TradingAccount id: 6, client_id: 8, trading_account_type_id: 2, ...> irb(main):003:0> ta.trading_account_type.id => 2 irb(main):004:0> ta.trading_account_type_id = 1 => 1 irb(main):005:0> ta.trading_account_type.id => 2

It means that after the trading_account_type_id change the object is not cleared and remains in the cache. I think that the change of trading_account_type_id should clear the cache and the following call to #trading_account_type should load from the database the one with id == 1

I've met this problem while establishing the validation:

  validates_uniqueness_of :trading_account_type_id, :scope => :client_id,     :if => Proc.new { |ta| ta.trading_account_type.singleton rescue nil }

that has to be rewritten as:

  validates_uniqueness_of :trading_account_type_id, :scope => :client_id,     :if => Proc.new { |ta|       tat = ta.trading_account_type       unless !tat || tat.id == ta.trading_account_type_id         tat = TradingAccountType.find ta.trading_account_type_id rescue nil       end       tat && tat.singleton?     }

What would you say?

2

Hello, All!

I've met the strange behavior and would like to ask the community if this is normal?

class TradingAccount < ActiveRecord::Base belongs_to :trading_account_type end

$ rails c Loading development environment (Rails 3.0.5) irb(main):001:0> TradingAccountType.all.map(&:id) => [1, 2] irb(main):002:0> ta = TradingAccount.find 6 => #<TradingAccount id: 6, client_id: 8, trading_account_type_id: 2, ...> irb(main):003:0> ta.trading_account_type.id => 2 irb(main):004:0> ta.trading_account_type_id = 1 => 1 irb(main):005:0> ta.trading_account_type.id => 2

It means that after the trading_account_type_id change the object is not cleared and remains in the cache.

I vaguely remember a ticket on the rails bug tracker about this. I don't remember what the resolution was.

Fred