Question

不幸的是这个混乱有效：你有没有建议清理这段代码：我正在尝试使用activerecord比较两个表列，“needed”和“amount”然后更新一个布尔列，具体取决于返回的数据。完全打破了不重复编码。

def update
    @inventory = Inventory.find(params[:id])

    respond_to do |format|
      if @inventory.update_attributes(params[:inventory])
            unless @inventory.needed.nil?
                if @inventory.needed < @inventory.amount then
                @inventory.instock = true
                @inventory.update_attributes(params[:inventory])
                else
                @inventory.instock = false
                @inventory.update_attributes(params[:inventory])
                end
            end
        flash[:notice] = 'Inventory was successfully updated.'
        format.html { redirect_to(@inventory) }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @inventory.errors, :status => :unprocessable_entity }
      end
    end
  end

干杯！

Answer 1

首先，将无关逻辑保留在控制器之外：

def update
  @inventory = Inventory.find(params[:id])

  respond_to do |format|
    if @inventory.update_attributes(params[:inventory])
      flash[:notice] = 'Inventory was successfully updated.'
      format.html { redirect_to(@inventory) }
      format.xml  { head :ok }
    else
      format.html { render :action => "edit" }
      format.xml  { render :xml => @inventory.errors, :status => :unprocessable_entity }
    end
  end
end

然后，使用Inventory模型上的回调处理instock属性。类似的东西：

before_update :check_instock, :unless => Proc.new { |inventory| inventory.needed.nil? } 

def check_instock
  if needed < amount
    instock = true
  else
    instock = false
  end
end

Answer 2

您对@inventory.update_attributes的多次调用非常困惑。只应在将记录保存到数据库时调用一次。您应该使用@inventory.attributes = params[:inventory]并使用if @inventory.save来访问数据库。

也许像（未经测试）：

@inventory.attributes = params[:inventory]
unless @inventory.needed.nil?
  @inventory.instock = (@inventory.needed < @inventory.amount) ? true : false
  @inventory.save
end

不幸的是，这有效：Activerecord中的ROR比较 - 更新

2 个答案: