wrong content loaded due to browser cache - ruby-on-rails

Question

I used Ruby on Rails for my website. In one web page, it will load a poll information based on the poll id, which set in url like "http://mywebsite/polls/1". The poll information includes the poll owner name, the poll title, the item pictures in the poll and the people's name who voted on the poll.
I found sometimes it loaded wrong information. That is, it loaded the wrong poll owner name, poll title and voted people from the other poll while the item pictures are correct.I checked the back end and found there was nothing wrong in rails controller. All the variables got the right values. But the chrome browser told me the view is wrong.
If I cleared all the cache and reload the page then it would work normally.Anyone knows why does it happen and what should I do? Thanks
The relavant action codes：
def show
#poll=Poll.where("is_deleted = false AND id = #{params[:id]}")[0]
#items=#poll.items.where("is_deleted = false")
#voted_user_ids = #poll.audiences.where('has_voted != 0').map(&:user_id).uniq
#voted_users = User.where('id IN (?)',#voted_user_ids)
#voted_user_names = #voted_users.map(&:user_name)
if current_user.nil?
#poll_vote_url = "/voted_choice"
else
#current_user_name = current_user.user_name
#poll_vote_url = "/audiences/"+#poll.id.to_s
#if_current_user_voted = #voted_users.include?(current_user)
#is_poll_owner = (current_user == #poll.user)
check_item_id_in_cookies
end
end
def check_item_id_in_cookies
if !cookies.signed[:item_id].nil?
item = Item.find(cookies.signed[:item_id].to_i)
#create audience if the voter is not the poll owner
if current_user == item.poll.user
flash.now[:alert] = "You can't vote on your own poll."
cookies.signed[:item_id] = nil
else
create_audience cookies.signed[:item_id]
end
end
end
def create_audience item_id
#item_id = item_id.to_i
#item = Item.find(#item_id)
#poll = #item.poll
#voted_user_ids = #poll.audiences.where('has_voted != 0').map(&:user_id).uniq
if #voted_user_ids.include?(current_user.id)
flash.now[:alert]="You already voted."
else
audience = #item.poll.audiences.find{|audience| audience.user_id == current_user.id} || Audience.create(:poll_id => #poll.id,:user_id => current_user.id)
#update audience
audience.is_following = true
audience.has_voted = #item.id
audience.save
cookies.signed[:item_id]=nil
flash[:alert]="Thank you for your vote"
redirect_to "/polls/#{#poll.id}"
end
end

Answer 1

Please monitor the network while loading and reloading the page. Especially to request to request to http://mywebsite/polls/1. Check the response headers as well. Even if you don't do on application side the web server or a proxy server may be modifying the request.
You can find help on who to use the network panel of chrome here.