驗證空nepost屬性

Question

我有模型BlogPost與嵌套屬性民意調查。

class BlogPost < ActiveRecord::Base 
    # attr_accessible :subject, :body, :tag_list, :commentable_by, :visible_by, :attachments_attributes 
    include ActiveModel::ForbiddenAttributesProtection 

    belongs_to :user 
    has_many :comments, as: :owner, dependent: :destroy 
    has_many :attachments, as: :owner, dependent: :destroy 
    has_many :photos, through: :attachments, source: :asset, source_type: 'Photo' 
    has_many :videos, through: :attachments, source: :asset, source_type: 'Video' 
    belongs_to :article 
    has_many :blog_post_subscriptions, dependent: :destroy 
    has_many :subscribers, through: :blog_post_subscriptions, class_name: 'User', source: :user 
    has_one :poll, as: :owner, dependent: :destroy 
    has_many :poll_items, dependent: :destroy 

    accepts_nested_attributes_for :attachments, :allow_destroy => true 
    accepts_nested_attributes_for :poll, allow_destroy: true, 
            reject_if: proc { |attributes| attributes['question'].blank? } 
    accepts_nested_attributes_for :poll_items, allow_destroy: true, 
           reject_if: proc { |attributes| attributes['answer'].blank? }         

    validates :user, :subject, :presence => true 
    validates :body, presence: true, if: :body_required? 
    validates :body, length: { maximum: 65000 } 
    validate :validate_duplicate, on: :create 


    before_create :check_paid_attributes 
    after_create :set_last_comment_at 
    before_save :set_tags_line 

模型輪詢嵌套屬性poll_items：

# == Schema Information 
# 
# Table name: polls 
# 
# id    :integer   not null, primary key 
# question  :string(255) 
# results_hidden :integer 
# from_date  :datetime 
# to_date  :datetime 
# owner_id  :integer 
# owner_type  :string(255) 
# created_at  :datetime   not null 
# updated_at  :datetime   not null 
# 
# Indexes 
# 
# index_polls_on_owner_id (owner_id) 
# 

class Poll < ActiveRecord::Base 
    POLL_ITEMS_COUNT_MAX = 5 
    attr_accessible :from_date, :question, :results_hidden, :to_date, :owner_id, :poll_items_attributes 

    belongs_to :owner, polymorphic: true 
    has_many :poll_items, dependent: :destroy 
    has_many :poll_votes, through: :poll_items 

    accepts_nested_attributes_for :poll_items, allow_destroy: true, 
           reject_if: proc { |attributes| attributes['answer'].blank? } 

    #validates :owner, :question, :from_date, :to_date, presence: true 
    #validate :validate_duplicate, on: :create 
    #validate :validate_max_poll_items 
    validates :poll_items, association_count: { maximum: POLL_ITEMS_COUNT_MAX } 
    validates :question, :from_date, :to_date, presence: true 

型號PollItem：

# == Schema Information 
# 
# Table name: poll_items 
# 
# id    :integer   not null, primary key 
# answer   :string(255) 
# poll_votes_count :integer 
# created_at  :datetime   not null 
# updated_at  :datetime   not null 
# post_id   :integer 
# blog_post_id  :integer 
# poll_id   :integer 
# sequence   :integer 
# 
# Indexes 
# 
# index_poll_items_on_blog_post_id (blog_post_id) 
# index_poll_items_on_poll_id  (poll_id) 
# index_poll_items_on_post_id  (post_id) 
# 

class PollItem < ActiveRecord::Base 
    attr_accessible :answer 
    attr_readonly :poll_votes_count 

    belongs_to :poll 
    belongs_to :post 
    has_many :poll_votes, dependent: :destroy 
    has_many :users, through: :poll_votes 

    validates :answer, presence: true 
    #validate :validate_duplicate, on: :create 

    #validates_uniqueness_of :answer, scope: :poll 

    scope :editable, lambda { |u| 
    unless u.moderator? 
     where(:poll.owner.user_id => u.id).where(:created_at.gt Settings.edit_delay.minutes.ago) 
    end 
    } 

    #before_validation do 
    #binding.pry 
    #self.poll = poll if poll 
    #end 


    private 
    def validate_duplicate 
    errors.add(:base, :duplicate) unless poll.poll_items.where(answer: answer).empty? 
    end 
end 

blog_posts_controller.rb

def new 
    @post = current_user.blog_posts.new 
    @poll = @post.build_poll 
    @poll.poll_items.build 
    end 

    def create 
    params[:blog_post][:draft] = params[:draft].present? 
    @post = current_user.blog_posts.create(blog_post_params) 

    redirect_to @post, notice: (@post.draft? ? 'Черновик сохранен' : 'Пост опубликован') 
    rescue ActiveRecord::RecordInvalid 
    flash[:error] = ":(" 
    render :new 
    end 

我正在創建一個新的博客文章與投票。如果我沒有指定答案（模型PollItem），則仍然創建輪詢。爲什麼？

有必要在空答案選項中沒有創建投票，並且顯示錯誤。

Answer 1

爲了驗證最小和最大關聯計數的博文& PollItem下面的驗證代碼添加到這兩種模式：

validates :poll_items, association_count: {minimum: 1, maximum: POLL_ITEMS_COUNT_MAX }