Rails Activerecord validates_presence_of 不闪烁错误信息

Question

我在 Rails 应用程序中有一个文本框，我想在保存到数据库之前验证输入的伪装。所以，我尝试在正确的模型中放置一个 validates_precense_of 回调（如下所示）。

class Suggestion < ActiveRecord::Base
  attr_accessible :details, :metadata, :suggestible, :user
  belongs_to :suggestable, polymorphic: true
  belongs_to :user
  serialize :metadata, JSON
  validates_presence_of :details
end

不是请求失败并闪烁错误消息，而是请求成功，建议表中不会保存任何建议记录。

我已经调试并确认（参见下面的控制器）@suggestion.details.blank? 和 .empty 返回 true 是文本框为空。

这是控制器动作：

  def select_patients
    @rx_search_request = RxSearchRequest.find(params[:id])
    @groups = []
    params['selected_patient_group'].each do |id, selected|
      @groups << id if selected == "true"
    end

      unless @groups.blank?

        @rx_search_request.select_multiple_patient_group_ids(@groups)

        unless @rx_search_request.approval_status_reason_patients_and_approval? ||
          @rx_search_request.approval_status_reason_requires_approval?
          @rx_search_request.needs_consolidation!
          # @rx_search_request.approve! approved_by: current_user
          @redirect_url = rx_search_request_path(@rx_search_request)
          # @message = "Request has been created."
        else
          @message = "Request has been forwarded to your admin for approval."
        end

      end
    if params.keys.include? "suggestion"
      #we are submitting a suggestion
      group_ids = params[:selected_patient_group].collect{|k,v| k if v == 'true'}.compact
      metadata = {
        group_ids:group_ids,
        patient_ids:ManualConsolidationPatientGroup.find(group_ids).collect{|g| g.manual_consolidation_patients}.flatten.collect{|_p| _p.id}
      }

      @suggestion = @rx_search_request.suggestions.new({
        details:params[:suggestion_box],
        metadata: metadata
      })
      @suggestion.user = current_user
      @suggestion.save
      # @message = "Your suggestion has been submitted."
      # debugger
      # flash[:alert] = 'Your suggestion cannot be blank' if @suggestion.details.empty?
      flash[:alert] = 'Your suggestion has been submitted.'
    end

    respond_to do |format|
      format.js
    end
  end

---

把控制器改成这个

unless @suggestion.details.blank?
        flash[:alert] = 'Your suggestion has been submitted.'
      else
        flash[:alert] = 'Your suggestion cannot be blank'
      end
      #debugger
      @suggestion.save!

也试过了

if @suggestion.save!
        flash[:alert] = 'Your suggestion has been submitted.'
      else
        flash[:alert] = 'Your suggestion cannot be blank'
      end

解决方案

添加 bang 运算符 ! 以进行正确保存

Answer 1

您需要检查save 调用的结果，或者改为save! 以使请求失败：

if @suggestion.save
  flash[:alert] = 'Your suggestion has been submitted.'
else
  flash[:alert] = 'Your suggestion cannot be blank'
end

如果您希望在 AJAX 请求之后显示验证错误，您需要在您的 <controller_name>.js.erb 文件中添加类似这样的内容：

<% flash.each do |type, message| %>
  $("#your_element_id").html("<%= type.to_s.humanize %>: <%= message.html_safe %>")
<% end %>

...您应该在其中将#your_element_id 更改为您的页面上呈现 Flash 消息的元素的实际 HTML ID。