Question

I am using Rails 3 and I would like to create an application that works like a thesaurus. I have read some tutorials on how to do has-and-belongs-to-many (HABTM) relationships, but I’m not sure how to configure my models such that one “item” has and belongs to many other items, i.e. its synonyms.

I suppose what I’m trying to do is a bit like a “related posts” section in a blog, where at the back-end each post must have several “related posts”.

Answer 1

I’d look at this as a many-to-many relationship where you need a separate model to handle the relationship.

class Word < ActiveRecord::Base
  has_many :source_words, :class_name=>"WordLink", :foreign_key=>:source_word_id
  has_many :linked_words, :class_name=>"WordLink", :foreign_key=>:linked_word_id

class WordLink < ActiveRecord::Base
  belongs_to :source_word, :class_name=>"Word"
  belongs_to :linked_word, :class_name=>"word"

Then you’d just need to do something like this to create / display words & synonyms:

w = Word.create(:word_name=>"Cold")
w.source_words.create(:linked_word=>Word.create(:word_name=>"Icy"))

synonyms_as_text_array = w.source_words.collect {|s| s.linked_word.word_name }