CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-4if-statementview
Thibaud Clement
Thibaud Clement

Reputation: 6907

Rails 4: conditional display not working inside view

In my Rails 4 app, there is a Post model, with both a :copy and a :short_copy attribute.

In the Posts#Show view, I want to display the :short_copy if it was defined by the user, and the :copy otherwise.

So, I implemented the following code:

<% if @post.short_copy %>
  <%= @post.short_copy %>
<% else %>
  <%= @post.copy %>
<% end %>

Problem: when the :short_copy is defined, it does show up, however, when it is not defined (and a :copy is defined), the :copy does not show up.

Is there something wrong with this code?

Upvotes: 1

Views: 120

Answers (4)

Meri Alvarado
Meri Alvarado

Reputation: 191

I always use string.blank? to check if nil or empty string. Use array.empty? if field is array. So in your case, you can use blank?

<% unless @post.short_copy.blank? %> <%= @post.short_copy %> <% else %> <%= @post.copy %> <% end %>

Upvotes: 1

Greg
Greg

Reputation: 6649

I just run this snippet: 

2.1.1 :002 > if("")
2.1.1 :003?>   printf "yes"
2.1.1 :004?>   else
2.1.1 :005 >     printf "no"
2.1.1 :006?>   end
(irb):6: warning: string literal in condition
yes => nil

So - if short_copy is empty string, it will evaluate to true. So try this:

2.1.1 :020 > unless("".empty?)
2.1.1 :021?>   printf "yes"
2.1.1 :022?>   else
2.1.1 :023 >     printf "no"
2.1.1 :024?>   end
no => nil

Upvotes: 1

Cody Caughlan
Cody Caughlan

Reputation: 32748

Use String#blank? to check for a value - an empty string is still true

<% if [email protected]_copy.blank? %>
  <%= @post.short_copy %>
<% else %>
  <%= @post.copy %>
<% end %>

Upvotes: 3

James Milani
James Milani

Reputation: 1943

I would argue that there is nothing wrong with your code in essence, but you may be mislead by the value of @post.short_copy. Unless it is nil or false the <% if @post.short_copy %> will be run. I would imagine that @post.short_copy = '', and is therefore displaying nothing in the view.

Upvotes: 2

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