CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-3ruby-on-rails-3.1ruby-on-rails-3.2
overallduka
overallduka

Reputation: 1549

How create record in HABTM Rails Association How make this?

I'm having some trouble creating a new relation in my has_and_belongs_to_many model. I defined the models like this:

journals model

  has_and_belongs_to_many :posts

post model

  has_and_belongs_to_many :journal

I don't know how create the association , I made a button but I don't know how it works. I created the action add_post

  def add_post
    @journal_post = JournalsPosts.new
  end

I make this link to create the association but I don't know what I have to do now:

<%= link_to "Add to Journal",:controller => "journals",:action => "add_post" %>

The redirect works correctly but I don't know how to proceed now ? Do you know about some guide to HABTM associations? I have already tried this, but it didn't help.

Upvotes: 5

Views: 9797

Answers (2)

shiggity
shiggity

Reputation: 561

After researching this myself, you should be able to do

def add_post
    j = Journal.first # or find_by, etc
    p = Post.first # or find_by, etc
    j.posts << p # creates a record in journals_posts table
    j.save!
end

(1) The accepted answer made it sound as though the association could only be made directly. Also you wouldn't have a "JournalsPosts" class if you're using the habtm association, since it specifically avoids using a model for the intermediary table.

(2) Note that this association will not be unique. If you call this multiple times, you'll get multiple entries in the journals_posts table with the same two integer pairs.

Upvotes: 16

Josh Rieken
Josh Rieken

Reputation: 2266

You should highly consider using has_many, :through as that's the preferred way to do these kinds of relationships now in Rails.

That said, if you want to continue with has_and_belongs_to_many, you need to somehow get the journal and post ids that you want to associate so you can correctly create the association.

In your routes:

resources :journals do
  member do
    put :add_post
  end
end

In your view (make sure you set @journal and @post somewhere):

<%= link_to "Add to Journal", add_post_journal_path(@journal, :post_id => @post.id), :method => :put %>

In your controller:

def add_post
  @journals_posts = JournalsPosts.new(:journal_id => params[:id], :post_id => params[:post_id])

  if @journals_posts.save
    ...
  else
    ...
  end
end

Upvotes: -3

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