Redmine

How about you use #to_a?
http://api.rubyonrails.org/classes/ActiveRecord/Associations/CollectionProxy.html#method-i-to_a

Toshi MARUYAMA wrote:

How about you use #to_a?
http://api.rubyonrails.org/classes/ActiveRecord/Associations/CollectionProxy.html#method-i-to_a

Where exactly do you suggest I use the to_a method?
Both exports (CSV and PDF) loop trough the available columns of the issue query and format the values for display. There is no place to specify that a certain value is a collection or to inject a transformation.
Rails uses to_a when calling a method from Enumerable (ex: collect) on an AR collection. This patch ensures that it gets called when the appropriate type is given (it could be a plain array or a proxy that resolves to an array).

Codruț Gușoi wrote:

Where exactly do you suggest I use the to_a method?

For example: r13248.

In your patch:

diff --git a/lib/redmine/export/pdf/issues_pdf_helper.rb b/lib/redmine/export/pdf/issues_pdf_helper.rb
index a7a4956..a3293a3 100644
--- a/lib/redmine/export/pdf/issues_pdf_helper.rb
+++ b/lib/redmine/export/pdf/issues_pdf_helper.rb
@@ -360,6 +360,8 @@ module Redmine
                 format_date(value)
               elsif value.is_a?(Time)
                 format_time(value)
+              elsif value.respond_to?(:collect)
+                value.collect(&:to_s).compact.join(', ')
               else
                 value
               end

How about joining value in your plugin?