Question

I’m trying to generate a link that creates a new object. It creates the object, but without setting the user_id or subreddit_id.

<%= link_to ' (add to my subreddits)', 
            { 
              controller: 'subscriptions',
              action: 'create',
              user_id: current_user.id,
              subreddit_id: subreddit.id
            },
              method: :post %>

here are the relevant controllers:

def new
@subscription = Subscription.new

unless current_user.admin?
  @subscription.user_id = current_user.id
end

respond_to do |format|
  format.html # new.html.erb
  format.json { render json: @subscription }
end
end

def create
@subscription = Subscription.new(params[:subscription])

unless current_user.admin?
  @subscription.user_id = current_user.id
end

respond_to do |format|
  if @subscription.save
    format.html { redirect_to @subscription, notice: 'Subscription was successfully created.' }
    format.json { render json: @subscription, status: :created, location: @subscription }
  else
    format.html { render action: "new" }
    format.json { render json: @subscription.errors, status: :unprocessable_entity }
  end
end
end

Answer 1

I guess your error is here:

# in create
@subscription = Subscription.new(params[:subscription])

You don’t set the value for subscription parameter. You set params[:user_id] and params[:subreddit_id]. Use them on creating your Subscription, like:

@subscription = Subscription.new(
  user_id: params[:user_id], 
  subreddit_id: params[:subreddit_id]
)