紅寶石在鐵軌上。 堆棧級別太深錯誤

Question

堆棧級別太深錯誤導致我的應用崩潰。 我有兩行存款模型：收入和提款。 這兩行由收入和提現模型中的after_create回調修改。 在Cashout模型中，我想使用before_create回調來驗證存款余額（創建Cashout后存款余額必須大於或等於0）並收到錯誤：CashoutsController＃create中的SystemStackError。

ps：收入回調工作正常。

代碼：

deposit.rb

class Deposit < ActiveRecord::Base
    belongs_to :user
    has_many :incomes
    has_many :cashouts
end

schema.rb

...

  create_table "deposits", force: true do |t|
    t.integer  "user_id"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.decimal  "income",     precision: 12, scale: 2
    t.decimal  "cashout",    precision: 12, scale: 2, default: 0.0
  end

cashout.rb

class Cashout < ActiveRecord::Base
    belongs_to :deposit
    validates :deposit_id, :order_sum, presence: true
    validates :order_sum, numericality: true
    validates :order_sum, numericality: { greater_than_or_equal_to: 0}
    before_create :validate_order #before_save crashed too
    after_create :update_deposit_cashout # working fine

    private

    def validate_order
        @deposit = self.deposit
        @income = @deposit.income
        @cashout = self.order_sum
        if @income - @cashout >= 0
            self.save
        else
            !self.save
        end
    end

    def update_deposit_cashout
        @deposit = self.deposit
        @deposit.update_attributes(:cashout => @cashout + self.order_sum)
    end
end

cashouts_controller.rb

class CashoutsController < ApplicationController
  before_action :signed_in_user, only: [:create]

  def new
    @cashout = @deposit.cashouts.build
  end

    def create
    @deposit = current_user.deposit
    @cashout = @deposit.cashouts.build(cashout_params)
    @cashout.save 
    if @cashout.save
      flash[:success] = "Your order request has been sent!"
      redirect_to '/deposit'
    else
      flash[:error] = "Your order request hasn't been sent!"
      redirect_to '/deposit'
    end
  end

  def show
    @deposit = Deposit.find(params[:id])
    @deposit.cashout
  end


  private

    def cashout_params
      params.require(:cashout).permit(:order_sum)
    end

end

income.rb

class Income < ActiveRecord::Base
    belongs_to :deposit
    validates :deposit_id, :order_sum, presence: true
    validates :order_sum, numericality: true
    validates :order_sum, numericality: { greater_than_or_equal_to: 0}

    after_create :update_deposit_income

    private

    def update_deposit_income
        @deposit = self.deposit
        if @deposit.income == nil
            @income = 0
        else
            @income = @deposit.income
        end
        @deposit.update_attributes(:income => @income + self.order_sum)
    end
end

incomes_controller.rb

class IncomesController < ApplicationController
  before_action :signed_in_user, only: [:create]

  def new
    @income = @deposit.incomes.build
  end

    def create
    @user = current_user
    @deposit = @user.deposit
    @income = @deposit.incomes.build(income_params) 
      @income.save
    if @income.save
      flash[:success] = "Your order request has been sent!"
      redirect_to '/deposit'
    else
      flash[:error] = "Your order request hasn't been sent!"
      redirect_to '/deposit' if current_user.present?
    end
  end

  def show
    @deposit = Deposit.find(params[:id])
    @deposit.income
  end


  private

    def income_params
      params.require(:income).permit(:order_sum)
    end

end

我的錯誤在哪里？

Answer 1

stack level too deep錯誤通常是由於代碼卡在一個循環中而發生的：一個方法調用自身，或者兩個方法反復調用。

在您的情況下，我認為這是由validate_order方法引起的。 您在before_save回調中調用此方法，該方法調用self.save ，將觸發該回調，該回調將再次調用該方法，該方法將再次保存，將觸發回調等。

暫時考慮一下-將對象保存為“ before_save”功能的一部分沒有意義嗎？

我懷疑您想做的只是驗證對象，如果驗證失敗，無論如何將自動阻止保存。 像這樣

validate :validate_order

def validate_order
  @deposit = self.deposit
  @income = @deposit.income
  @cashout = self.order_sum
  if @income - @cashout <= 0
    self.errors.add(:deposit, "is too small")
  end
end

這只是一個示例，因為我不知道您要測試的內容的實際邏輯是什么。