adds proposal model

app/models/proposal.rb

@@ -0,0 +1,57 @@
+class Proposal < ActiveRecord::Base
+  apply_simple_captcha
+
+  belongs_to :author, -> { with_hidden }, class_name: 'User', foreign_key: 'author_id'
+  has_many :comments, as: :commentable
+  has_many :flags, as: :flaggable
+
+  validates :title, presence: true
+  validates :description, presence: true
+  validates :author, presence: true
+  validates :question, presence: true
+
+  validate :validate_title_length
+  validate :validate_description_length
+
+  validates :terms_of_service, acceptance: { allow_nil: false }, on: :create
+
+  before_validation :sanitize_description
+  before_validation :sanitize_tag_list
+
+  def self.title_max_length
+    @@title_max_length ||= self.columns.find { |c| c.name == 'title' }.limit || 80
+  end
+
+  def self.description_max_length
+    6000
+  end
+
+  protected
+
+    def sanitize_description
+      self.description = WYSIWYGSanitizer.new.sanitize(description)
+    end
+
+    def sanitize_tag_list
+      self.tag_list = TagSanitizer.new.sanitize_tag_list(self.tag_list)
+    end
+
+  private
+
+    def validate_description_length
+      validator = ActiveModel::Validations::LengthValidator.new(
+        attributes: :description,
+        minimum: 10,
+        maximum: Proposal.description_max_length)
+      validator.validate(self)
+    end
+
+    def validate_title_length
+      validator = ActiveModel::Validations::LengthValidator.new(
+        attributes: :title,
+        minimum: 4,
+        maximum: Proposal.title_max_length)
+      validator.validate(self)
+    end
+
+end