Question

Does Ruby (or Rails) provide an easy way to accomplish the following:

if @author.articles.each(:published == true)
  puts "all articles of this author are published"
end

I think the example speaks for itself.

Answer 1

Maybe someone will find something better, but here are some things that would work:

unless @author.articles.map{|a| a.published == true}.include?(false)
  puts "all articles of this author are published"
end

or…

if @author.articles.select{|a| !a.published}.size == 0
  puts "all articles of this author are published"
end

or…

if @author.articles.detect{|a| !a.published}.nil?
  puts "all articles of this author are published"
end

My preference goes for the last one.