If user has at least one then show something else show other - ruby-on-rails

Question

I am writing a basic index page where I want to show a user a list of their credits cards if they have any, else I want to show them an add credit card button.
I know the statement is something like if current_user >1 credit_card
I have user model using devise and a credit_card model and basically I want to show the following.
<% if current_user has atleast 1(>1) credit_card>
show this
<% else %>
show that
<% end %>
Credit_Cards Controller
class CreditCardsController < ApplicationController
before_action :authenticate_user!
before_action :set_credit_card, only: [:show, :edit, :update, :destroy]
# GET /credit_cards
# GET /credit_cards.json
def index
#credit_cards = current_user.credit_cards
#credit_card_debt = current_user.credit_cards.sum(:card_balance)
#credit_limit = current_user.credit_cards.sum(:card_limit)
#available_credit = current_user.credit_cards.sum(:card_limit) - current_user.credit_cards.sum(:card_balance)
end
# GET /credit_cards/1
# GET /credit_cards/1.json
def show
end
# GET /credit_cards/new
def new
#credit_card = current_user.credit_cards.build
end
# GET /credit_cards/1/edit
def edit
end
# POST /credit_cards
# POST /credit_cards.json
def create
#credit_card = current_user.credit_cards.new(credit_card_params)
respond_to do |format|
if #credit_card.save
format.html { redirect_to #credit_card, notice: 'Credit card was successfully created.' }
format.json { render :show, status: :created, location: #credit_card }
else
format.html { render :new }
format.json { render json: #credit_card.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /credit_cards/1
# PATCH/PUT /credit_cards/1.json
def update
respond_to do |format|
if #credit_card.update(credit_card_params)
format.html { redirect_to #credit_card, notice: 'Credit card was successfully updated.' }
format.json { render :show, status: :ok, location: #credit_card }
else
format.html { render :edit }
format.json { render json: #credit_card.errors, status: :unprocessable_entity }
end
end
end
# DELETE /credit_cards/1
# DELETE /credit_cards/1.json
def destroy
#credit_card.destroy
respond_to do |format|
format.html { redirect_to credit_cards_url, notice: 'Credit card was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_credit_card
#credit_card = CreditCard.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def credit_card_params
params.require(:credit_card).permit(:card_name, :card_provider, :points_provider, :interest_rate, :card_balance, :card_limit, :user_id )
end
end
Credit Card Model
class CreditCard < ApplicationRecord
belongs_to :user
def credit_available
card_limit - card_balance
end
def annual_interest
card_balance * interest_rate
end
def minimum_payment
n = card_balance / 100
b = n * 1
i = card_balance * interest_rate
c = i / 12
c + b
end
def total_monthly_payment
total_monthly_payment = 0
#total_monthly_payment = total_monthly_payment + current_user.credit_cards.minimum_payment.sum
end
end

Answer 1

You have used this #credit_cards = current_user.credit_cards the line in the index action that's why you don't need to use current_user on the index.html.erb file because above line make sure you have credit card or no then your HTML file looks like
<% if #credit_cards.count >= 1 %>
show this
<% else %>
show that
<% end %>
Or you can use something like this
<% if #credit_cards.any? %>
show this
<% else %>
show that
<% end %>
Or you can use something like this
<% if current_user.credit_cards.count >= 1 %> #=> or current_user.credit_cards.any?
show this
<% else %>
show that
<% end %>
That's time you don't need this #credit_cards = current_user.credit_cards from index action
Here is you can see some if else basic explanation of Ruby The Bastards Book of Ruby