How to add to_sentence to a :collection - ruby-on-rails-3

Question

I have the following code that generates a list of superlatives:
<%= render :partial => 'superlative', :collection => #profile.superlatives %>
The :partial code referenced above is as follows:
<li class="superlative"><span title="<%= superlative.name %>">
<%= superlative.body %>
</span></li>
How can I add to_sentence to the #profile.superlatives collection? I tried:
<%= render :partial => 'superlative', :collection => #profile.superlatives.to_sentence %>
Doing so however makes the #profile.superlatives disappear from the view.
I looked at the docs but couldn't find an answer.

Answer 1

Ohhh, now I understand. Sorry for the confusion. Here's what I would do:
In your controller:
#superlative_bodies = #profile.superlatives.map &:body
# Equivalent to: #superlative_bodies = #profile.superlatives.map {|sup| sup.body }
In your view:
= #superlative_bodies.to_sentence
Some people would do this all in the view instead, which is up to you:
= #profile.superlatives.map(&:body).to_sentence
To explain, .map is a super-useful Ruby method that takes an array or other Enumerable and a block and returns a new array where each element is the corresponding element from the original array after the block has been applied to it. For example:
[ 'foo', 'bar', 'baz' ].map {|word| word.upcase } # => [ 'FOO', 'BAR', 'BAZ' ]
# or
[ 'foo', 'bar', 'baz' ].map &:upcase # => [ 'FOO', 'BAR', 'BAZ' ]
(The latter is just a shortened version of the former for when you only want to call the same single method on every element.)

Answer 2

Something like this, perhaps?
module ProfilesHelper
# ...
def superlatives_items (profile)
##acb ||= ActionController::Base.new # required to access render_to_string
profile.superlatives.collect |superlative|
acb.render_to_string :partial => 'path/to/partial/superlative',
:layout => false,
:locals => { :superlative => superlative }
end
end
# ...
end
# In view:
# <%= raw(superlatives_items(#profile).to_sentence) %>