Fix bug.

app/models/journal_paper.rb

@@ -31,7 +31,7 @@ class JournalPaper
   # paginates_per 10
   
   #relations
-  has_and_belongs_to_many :member_profile, class_name: "MemberProfile", foreign_key: 'member_profile_id'
+  field :member_profile_id, type: Array
 
   belongs_to :journal_paper_type
   has_and_belongs_to_many :journal_types
@@ -54,9 +54,23 @@ class JournalPaper
   scope :sort_year_date, ->{ order_by(:year => "desc", :publication_date => "desc", :id=>"desc") }
   scope :sort_for_frontend, ->{ where(:is_hidden=>false).order_by(:year => "desc", :publication_date => "desc", :id=>"desc") }
 
-  alias_method :member_profiles, :member_profile
-  alias_method :member_profiles=, :member_profile=
-  alias_method :org_member_profile=, :member_profile=
+  before_save :fix_member_profile_id
+  after_save :reload_member_profiles
+
+  def fix_member_profile_id
+    org_member_profile_id = self[:member_profile_id]
+    if org_member_profile_id.class == Array
+      self.member_profile_id = self[:member_profile_id].map{|id| BSON::ObjectId(id)}
+    else
+      self.member_profile_id = Array(org_member_profile_id).compact.map{|id| BSON::ObjectId(id)}
+    end
+    true
+  end
+  def reload_member_profiles
+    @member_profiles = MemberProfile.where(:id.in=>self.member_profile_id).to_a
+    @member_profile = @member_profiles.first
+    return @member_profiles
+  end
 
   def create_link
     title = []
@@ -215,12 +229,33 @@ class JournalPaper
     plugin_datas
   end
 
-  def member_profile()
-    member_profiles.first
+  def member_profiles
+    @member_profiles ||= MemberProfile.where(:id.in=>self.member_profile_id).to_a
+    @member_profiles
+  end
+
+  def member_profiles=(mps)
+    self.member_profile_id = mps.map(&:id)
+    @member_profiles = mps
+    @member_profile = @member_profiles.first
+    @member_profiles
+  end
+
+  def member_profile
+    @member_profile ||= MemberProfile.where(:id.in=>self.member_profile_id).first
+    @member_profile
   end
 
   def member_profile=(mp)
-    org_member_profile=(mp.class != MemberProfile ? mp : [mp])
+    if mp.class == MemberProfile
+      self.member_profile_id = [mp.id]
+       @member_profiles = [mp]
+       @member_profile = mp
+    else
+      self.member_profile_id = mp.map(&:id)
+       @member_profiles = mp
+       @member_profile = mp.first
+    end
   end
 
   def get_plugin_field_data(field)