Ruby - why this construction return nil?

Question

I have this simple construction:

<% if [email protected]? && [email protected]? %>
   <%= @user.address+', '[email protected]%>
<% end %>

If are address and zip filled out, it's ok. But if not, on localhost is not printed out the middle line. That's ok as well.

But on Heroku, if address and zip are not filled out, I get the error

ActionView::Template::Error (undefined method `empty?' for nil:NilClass):

How is that possible? Note: address and zip have the datatype varchar(255).

EDIT: I forgot to add an important note: @user is NEVER nil.

Answer 1

Try using present?

Under the surface present? is just !blank? which will test for empty strings as well as for nil, {} and [].

In your case:

<% if @user.address.present? && @user.zip.present? %>
  <%= "#@user.address, #@user.zip" %>
<% end %>

Answer 2

You can use empty? only on [], {}, "", " " but not on nil.

Use blank? instead:

[email protected]? && [email protected]?

To make it affirmative use present?:

@user.address.present? && @user.zip.present?