CODEWITHSUNDEEP
rubysinatradatamapper
user1576633
user1576633

Reputation: 167

DataMapper Self Referential Model

I have a model: 

class Comment
   include DataMapper::Resource
   property :id, Serial
   property :comment, Text, :required => true  
   belongs_to :user
   belongs_to :lecture
   has n, :replies, :child_key => [:source_id]
   has n, :comments, self, :through => :replies, :via => :target
end

And I want to add a comment as a reply to another, already created comment. When I try: 

lecture = Lecture.get(params[:lecture_id])
comment = Comment.new(:comment => params[:text])  
@user.comments << comment
lecture.comments << comment 

if !params[:parent].nil? then
  parent = Comment.get(params[:parent])
  parent.replies << comment
end

The line parent.replies << comment throws the error:
NoMethodError - undefined method source_id=' for #<Comment @id=nil @comment="asd" @user_id=1 @lecture_id=1>

My Reply model is:

class Reply 
 include DataMapper::Resource 
  belongs_to :source, 'Comment', :key => true
  belongs_to :target, 'Comment', :key => true
end

How do I correctly add a comment as a 'reply'? Thanks.

Upvotes: 0

Views: 112

Answers (1)

ujifgc
ujifgc

Reputation: 2245

Are you sure you want Reply model? The comment tree can be build on just one model Comment that has self-association.

class Comment
  ...
  has n, :replies, 'Comment', :child_key => :source_id
  belongs_to :source, 'Comment', :required => false
end

Upvotes: 1

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