Question

I’m a newbie to rails development.
I have a custom method placed in my Post class, in which I want to update a particular attribute/variable of that Post class. My method goes as below:-

def update_bid_winner (winner_id)
  @bid_winner_id = winner_id
  puts @bid_winner_id
  save
  puts "post saved"
end

But when I display the Post object , the bid_winner_id variable is still not updated.
I doubt that the object’s save is not successful after the updation, because
the puts placed the above method prints the correct value with which I’m trying to update.

Logs from my rails server window:-

2      <<< Output of the puts placed for debugging
post saved


Started GET "/posts/1/bids/1/offer_bid" for 127.0.0.1 at Sun Nov 21 13:21:59 +0530 2010
Processing by BidsController#offer_bid as HTML
Parameters: {"post_id"=>"1", "id"=>"1"}
User Load (3.1ms)  SELECT "users".* FROM "users" WHERE ("users"."id" = 1) LIMIT 1
Post Load (3.1ms)  SELECT "posts".* FROM "posts" WHERE ("posts"."id" = 1) LIMIT 1
Bid Load (0.5ms)  SELECT "bids".* FROM "bids" WHERE ("bids"."id" = 1) LIMIT 1
Redirected to http://localhost:3000/posts/1
Completed 302 Found in 167ms

My post schema as follows:-

create_table "posts", :force => true do |t|
t.integer  "user_id"
t.string   "title"
t.text     "body"
t.integer  "bid_winner_id"
end  

What Am i doing wrong here ???

Answer 1

You don’t need a custom method to accomplish this. Rails has a handy method called update_attribute:

@post.update_attribute(:bid_winner_id,winner_id)

which will work, but even that is not idiomatic Rails. If a Post is associated to the BidWinner model, and assuming you found (or created) a BidWinner and assigned it to @bid_winner), then you simply say:

@post.bid_winner = @bid_winner
@post.save

One other thing — you aren’t really updating this via a GET, are you? That would generally not be a good thing.