Rails 4: Insert Attribute Into Params

nullnullnull picture nullnullnull · May 13, 2013 · Viewed 49.5k times · Source

In Rails 3, it was possible to insert an attribute into params like so:

params[:post][:user_id] = current_user.id

I'm attempting to do something similar in Rails 4, but having no luck:

post_params[:user_id] = current_user.id

. . . .


private

  def post_params
    params.require(:post).permit(:user_id)
  end

Rails is ignoring this insertion. It doesn't throw any errors, it just quietly fails.

Answer

nullnullnull picture nullnullnull · May 14, 2013

Found the answer here. Rather than inserting the attribute from within the controller action, you can insert it into the params definition with a merge. To expand upon my previous example:

private

  def post_params
    params.require(:post).permit(:some_attribute).merge(user_id: current_user.id)
  end