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daily learnings as a ruby dev

Build Robust & Production Quality Applications - Lesson 4: Transactions & Exception Resues

17 Mar 2015

The[ previous example reegarding updating video review while in queue does not follow typical Rails convention: - We are using in the updatequeue method. - we have to use parameter naming conventions to parse out the queueitem id and position id in the form. - We have to specify the order of queue_items using in the user model according to position.

Using Transactions & Exception Rescues when the value does not save.

def update_queue
  begin
    ActiveRecord::Base.transaction do
      params[:queue_items].each do |queue_item_data|
        queue_item = QueueItem.find(queue_item_data["id"])
        queue_item.update_attributes!(position: queue_item_data["position"])
      end
    end
  rescue ActiveRecord::RecordInvalid
    flash[:error] = "You must use whole numbers for play position."
    redirect_to my_queue_path
    return
  end

  current_user.queue_items.each_with_index do |queue_item, index|
    queue_item.update_attributes(position: index+1)
  end
  redirect_to my_queue_path
end

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