更改模型回调的参数值

Question

所以我有 3 个模型 group、recipient 和 group_recipients。

class Group < ApplicationRecord
    has_many :group_recipients, dependent: :destroy
    has_many :recipients, through: :group_recipients
end

class GroupRecipient < ApplicationRecord
    belongs_to :recipient, inverse_of: :group_recipients, autosave: true
    belongs_to :group
end

class Recipient < ApplicationRecord
    has_many :group_recipients, inverse_of: :recipient, autosave: true, dependent: :destroy
    has_many :groups, through: :group_recipients
end

控制器#update recipients_controller.rb

def update
 @recipient = Recipient.with_deleted.find(params[:id])
 if @recipient.update(recipient_params)
  respond_to do |format|
    redirect_url = params[:commit] == 'Save and add another' ? new_recipient_path : edit_recipient_path(@recipient)
    format.html { redirect_to redirect_url, notice: 'Recipient was successfully updated.' }
    format.json { render json: {status: :success} }
  end
else
  respond_to do |format|
    format.html { render :edit }
    format.json do
      render json: {
        status: :error,
        recipient: @recipient,
        errors: @recipient.errors
      }
    end
  end
end
end

 def recipient_params
   params.require(:recipient).permit(
   :email_address, :first_name, :last_name, :language_id,
   :phone, group_ids: [])
 end

在收件人update，收到params[:group_ids]。在这里，在before_update 回调中，我希望能够通过一些逻辑更改group_ids 值。我可能需要在 group_ids 数组中添加或删除数据。

问题是 activerecord 根据params[:group_ids] 更新所有组，即使我更改它。我在回调之前还是之后使用它都没有关系。一旦我在self.group_ids 中设置了值，它确实会进行这些更改，但是一旦事务完成，它会再次恢复这些更改。

Answer 1

在回调 before_update 中进行更新的想法不好，你会遇到递归错误的问题。另一种方法是根据控制器中的逻辑更改参数，然后您可以使用正常的更新方法。