I'm very newbie in ruby and need your help.

I must save a "Topic" and make it like this :

@topic = Topic.new(params[:topic])

But I would like to pass an other information to this topic. It has a field "community_id" that link it to a community. The logged user has this information on his table.

How can I pass the "community_id" from the logged user to the "community_id" of the "topic" created ?

thx for your help