將公共屬性注入activerecord類的正確方法是什麼？

Question

我計劃使用該模塊（全exmpample這裏http://pastie.org/1098444）

puts "Name_and_key was referenced." 

module Name_and_key 

    def normalize(s) 
    s.mb_chars.normalize(:kd).gsub(/[^\-x00-\x7F]/n, '').to_s 
    end 

    def name=(name) 
    self[:name] = name 
    self[:key] = normalize(name).downcase 
    end 

    def name 
    self[:name] 
    end 

    def key=(key) 
    self[:key] = normalize(key).downcase 
    end 

    def key 
    self[:key] 
    end 

end 

但似乎這些值不會在模型到達。

class Category < ActiveRecord::Base 
    include Name_and_key 

    has_many :tiles 
    validates_presence_of :name, :key 
end 

和

cat = Category.create do |c| 
c.name = "cat" 
end 

ActiveRecord::StatementInvalid: SQLite3::ConstraintException: categories.name may not be NULL: INSERT INTO "categories" ("created_at", "updated_at", "id") VALUES ('2010-08-15 23:20:43', '2010-08-15 23:20:43', 980190962)

這是一種有效的方法可言，如果不是怎麼能這樣做？如果確實，我的錯誤是什麼？

發生故障的單元測試

test "can be created" do 
cat = Category.create do |c| 
    c.name = "cat" 
end 
tile = Tile.create do |t| 
    t.name = "test" 
    t.category = cat 
end 
assert tile.save 

端

某些跟蹤

1) Error: 

test_can_be_created（TileTest）： 的ActiveRecord :: StatementInvalid：SQLite3的:: ConstraintException：categories.name不得NULL：INSERT INTO「categories」（「created_at」，「updated_at」，「id」）VALUES（'2010-08-16 02:06:43'，'2010-08-16 02:06:43'，980190962 ） /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/abstract_adapter.rb:202:in rescue in log' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/abstract_adapter.rb:194:in log' /Users /janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/sqlite_adapter.rb:135:in execute' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/abstract/database_statements.rb:239:in insert_fixture' /Users/janlimpens/.rvm/gems/ruby​​-1.9.2-rc2在rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb：634：在block in insert_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:570:in每個' /Users/janlimpens/.rvm/gems/ ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb：570：在insert_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:514:in塊（4級）in create_fixtures' /Users/janlimpens/.rvm/gems /ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:514:in each' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:514:in block（ 3個等級）in create_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/abstract/database_statements.rb:139 ：在transaction' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:512:in block（2 levels）in create_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/connection_adapters/abstract_adapter。 rb：104：在012_block in create_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activesupport-3.0.0.rc/lib/active_support/benchmarkable.rb:55 ：silence' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:502:in create_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:961:in load_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activerecord-3.0.0.rc/lib/active_record/fixtures.rb:926:in setup_fixtures' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activesupport-3。 0.0.rc/lib/active_support/callbacks.rb：409：在_run_setup_callbacks' /Users/janlimpens/.rvm/gems/ruby-1.9.2-rc2@rails3/gems/activesupport-3.0.0.rc/lib/active_support/testing/setup_and_teardown.rb:34:in運行'

Answer 1

我建議添加validates_presence_of :name捕獲紅寶石側的錯誤。您的應用程序會嘗試將看似有效的對象保存到數據庫中，名稱爲NULL，Ruby允許這樣做。現在你的DB爆炸了，因爲你在那裏設置了一個NOT NULL，它不喜歡你在那裏保存的東西。