Rails的模型邏輯給出錯誤的結果

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當我做複製到一些變量後科拉姆值一些邏輯，在對象上我的實際科拉姆價值得到改變，我的模型方法，Rails的模型邏輯給出錯誤的結果

def copy_configuration_values 
    element_positions_dup = element_positions.dup 
    cert_element.read_attribute(:field_names)["configuration_values"].each { |k, v| 
     element_positions_dup["configuration_values"][k] = v if configuration_value_present?(k) 
    } 
    element_positions_dup 
    end 

    def configuration_value_present?(configuration) 
    element_positions["configuration_values"] && element_positions["configuration_values"][configuration] 
    end

當我從下面的控制檯調用此方法，

1.9.3p194 :001 > t = CertTemplate.find 30 
CertTemplate Load (0.3ms) SELECT `cert_templates`.* FROM `cert_templates` WHERE `cert_templates`.`id` = 30 LIMIT 1 
=> #<CertTemplate id: 30, name: "aaaaaaaaaaaq", cert_element_id: 22, element_positions: {"configuration_values"=>{"Program"=>"9.523810492621529,24.627720154437824"}, "custom_fields"=>{"college"=>"22.64550296843998,15.349369638973906", "code"=>"16.79,15.463920671915272"}, "custom_fields_for_rows"=>{"subject name"=>"30.68783230251736,16.609393247624034"}}, created_at: "2012-08-08 07:18:33", updated_at: "2012-08-16 08:03:52", image_file_name: "Marksheet_Updated.jpg", image_content_type: "image/jpeg", image_file_size: 2236497, image_updated_at: "2012-08-08 07:18:33"> 
1.9.3p194 :002 > 
1.9.3p194 :003 > t.copy_configuration_values 
CertElement Load (0.2ms) SELECT `cert_elements`.* FROM `cert_elements` WHERE `cert_elements`.`id` = 22 LIMIT 1 
=> {"configuration_values"=>{"Program"=>"2"}, "custom_fields"=>{"college"=>"22.64550296843998,15.349369638973906", "code"=>"16.79,15.463920671915272"}, "custom_fields_for_rows"=>{"subject name"=>"30.68783230251736,16.609393247624034"}} 
1.9.3p194 :004 > 
1.9.3p194 :005 > t 
=> #<CertTemplate id: 30, name: "aaaaaaaaaaaq", cert_element_id: 22, element_positions: {"configuration_values"=>{"Program"=>"2"}, "custom_fields"=>{"college"=>"22.64550296843998,15.349369638973906", "code"=>"16.79,15.463920671915272"}, "custom_fields_for_rows"=>{"subject name"=>"30.68783230251736,16.609393247624034"}}, created_at: "2012-08-08 07:18:33", updated_at: "2012-08-16 08:03:52", image_file_name: "Marksheet_Updated.jpg", image_content_type: "image/jpeg", image_file_size: 2236497, image_updated_at: "2012-08-08 07:18:33"> 
1.9.3p194 :006 >

我的實際列值發生了變化，我做錯了什麼。提前謝謝。

來源

2012-09-10 Mohanraj

什麼是'element_positions'變量？ – AJcodez

這是一個散列。例如：{「configuration_values」=> {「Program」=>「9.523810492621529,24.627720154437824」}，「custom_fields」=> {「college」=>「22.64550296843998,15.349369638973906」，「code」=>「16.79,15.463920671915272」}，「custom_fields_for_rows」=> {「subject name」=>「30.68783230251736,16.609393247624034」}} – Mohanraj

看起來問題是，當您遍歷鍵值而不是副本時，您正在分配對嵌套散列的引用。

特別是，element_positions和element_positions_dup中的「custom_fields」鍵將指向與該值相同的Hash對象，因爲您將其指定爲不重複該值。要修復它試圖

... 
element_positions_dup["configuration_values"][k] = v.dup if configuration_value_present?(k) 
...

編輯：是的，你需要深拷貝

Use Marshal serialization

來源

2012-09-10 10:03:11 AJcodez

感謝您的回覆。我曾嘗試使用v.dup，但原始散列正在改變。 – Mohanraj

嗨，我使用了deep_dup「element_positions_dup = element_positions.deep_dup」。 – Mohanraj

Rails的模型邏輯給出錯誤的結果

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