postgresql - How to get Rails 4 if a record has two conditions return true else false? -

postgresql - How to get Rails 4 if a record has two conditions return true else false? -

i'm setting vote system, , trying have helper model can check if user has voted card. i'm new rails , can't seem figure 1 out.

how have model check votes record has user_id of current_user , card_id?

i'm trying limit calling helper many times each iteration of _cards.html.erb setting voted variable. not sure how this, trying set variable printing true every card, ones have no votes.

setting variable not working , neither helper, true.

cards_controller.rb:

def if_voted(card_id) if vote.where(:user_id => current_user.id, :card_id => card_id) true else false end end helper_method :if_voted

_cards.html.erb:

<td> <%= @voted = if_voted(card.id) %> <% if @voted == true %> <span class="green"><center> <% elsif @voted == false %> <span class="red"><center> <% else %> <span class="gray"><center> <% end %> <%= card.up_votes - card.down_votes %> </center></span> </td>

with help of @tadman

cards_controller.rb

def if_voted(card_id) if vote.where(:user_id => current_user.id, :card_id => card_id).any? @vote = vote.find_by(:user_id => current_user.id, :card_id => card_id) homecoming @vote.voted else homecoming nil end end helper_method :if_voted

_cards.html.erb

<td> <% @voted = if_voted(card.id) %> <% if @voted == true %> <span class="green"><center> <% elsif @voted == false %> <span class="red"><center> <% else %> <span class="gray"><center> <% end %> <%= card.up_votes - card.down_votes %> </center></span> </td>

thank you

the where method returns scope if scope not contain records. find_by method uses same options returns either first matching record or nil if none found.

that's not quite want here, though. don't want retrieve of records, instead check if exist. any? method on scope true if 1 or more records exist, or false otherwise.

you should update code this:

def if_voted(card_id) vote.where(:user_id => current_user.id, :card_id => card_id).any? end

it's worth noting few things ruby style:

using then @ end of if clause, while supported, extraneous , not done. comparing things == true sign logic confused. if you're concerned beingness literal true rather logically true, utilize === true instead. in case, close plenty counts, if (if_voted(...)) should suffice. your method returned either true or false had 3 conditions if expecting maybe pop 1 day. method names if_voted little clumsy, if used within if. has_voted? much more in line ruby , rails in general, if (has_voted?(...)) reads lot better. even improve migrate method user class can eliminate helper , end if (current_user.has_voted?(card_id)) clear way of expressing intent.

ruby-on-rails postgresql helper