Rails erb formatting troubles, phantom spaces - ruby-on-rails

Question

Halp! My template is formatting strangely and I can't fathom how/why.
<% #poll.questions_all.each do |q| %>
<td>
<span class="optionvalue">
<% if can? :read_full, #poll %>
<%= resp[:texts][q.id] %>
<% else %>
<%= resp[:texts][q.id].nil? ? '' : resp[:texts][q.id].gsub(Question::POISON_WORDS_REGEX, '---') %>
<% end %>
</span>
<% unless q.options.empty? %>
<%= q.get_matching_option(resp[:texts][q.id])? ": #{q.get_matching_option(resp[:texts][q.id])}" : '' %>
<% end %>
</td>
<% end %>
Results in this:
A : Playgrounds
No idea where that first space is coming form, and every effort to get rid of it has failed! The generated markup:
<td>
<span class="optionvalue">
A
</span>
: Playgrounds
</td>

Answer 1

Try using the <%- -%> version of erb tags, these should suppress the extra whitespaces:
<%- if can? :read_full, #poll -%>
<%= resp[:texts][q.id] %>
<%- else -%>
<%= resp[:texts][q.id].nil? ? '' : resp[:texts][q.id].gsub(Question::POISON_WORDS_REGEX, '---') %>
<%- end -%>
I don't recall if you need them in both the opening and ending tags, but I'd suggest playing around with it and see if you can get what you want.

Answer 2

Horrible solution, but it works:
<% #poll.questions_all.each do |q| %>
<td>
<span class="optionvalue">
<% if can? :read_full, #poll %>
<%= resp[:texts][q.id] %></span><%= q.get_matching_option(resp[:texts][q.id])? ": #{q.get_matching_option(resp[:texts][q.id])}" : '' unless q.options.empty? %>
<% else %>
<%= resp[:texts][q.id].nil? ? '' : resp[:texts][q.id].gsub(Question::POISON_WORDS_REGEX, '---') %></span><%= q.get_matching_option(resp[:texts][q.id])? ": #{q.get_matching_option(resp[:texts][q.id])}" : '' unless q.options.empty? %>
<% end %>
</td>
<% end %>

Answer 3

I am pretty sure erb will do the right thing (not add unwanted lines) if you keep everything on one line of HTML.
For this case, and in general, I recommend that you put any logic for generating the content in methods in the view helper file (or if you're feeling lazy, in a code block in the erb, as in this example):
<% #poll.questions_all.each do |q| %>
<%
if can? :read_full, #poll
texts = resp[:texts][q.id]
else
texts = (resp[:texts][q.id].nil? ? '' : resp[:texts][q.id].gsub(Question::POISON_WORDS_REGEX, '---'))
end
if q.options.empty?
matching_options = ''
else
matching_options = (q.get_matching_option(resp[:texts][q.id])? ": #{q.get_matching_option(resp[:texts][q.id])}" : '')
end
%>
<td>
<span class="optionvalue"><%= texts %></span><%= matching_options %>
</td>
<% end %>