Ruby on Rails Resque perform paramters as hash

Question

I'm trying to write a resque worker to handle some background tasks like mass emailing.

What I'd like is for my worker to accept a hash of arguments:

class Worker
  @queue = :worker_queue

  def self.perform(options={})
    user_id = options[:user_id]
  end
end

Which I prefer over self.perform(arg1, arg2, arg3, arg4, arg5) .

Everything works in console (ie Worker.perform(args) ). However, whenever I queue this into resque the arguments are undefined.

ActiveRecord::RecordNotFound: Couldn't find User with 'id'=

Can anyone point me in the right direction? I know that the enqueued paramters are serialized into JSON.

I just thought about it and could my problem be the symbol :user_id instead of 'user_id' , since it is serialized?

Answer 1

Yes, it's correct. The following code is the culprit

user_id = options[:user_id]

Specifically, the use of a symbol in the hash ( :user_id ) can cause the trouble because when the parameters are serialized/deserialized, the Hash you get in the Resque worker contains all the keys as strings.

You should use:

user_id = options["user_id"]

Answer 2

Yes my suspicions were correct! When serialized to JSON, a Ruby symbol becomes a regular key string.

As soon as I replaced the previous code's symbols with 'user_id' , everything started working!