Concatenate array and string for CSV - ruby

Question

I'm attempting to concatenate a string to an array value. Since the URL/domain is the same, I simply store the users email prefix and append the url/domain. I need to export the full email address out to CSV:
CSV.generate(options) do |csv|
columns = %w(name, email_address)
url = "#example.com"
all.each do |location|
csv << location.attributes.values_at(*columns) + [url]
end
end
Currently the resulting output is:
Joe, user1, #example.com
Bob, user2, #example.com
What I need is:
Joe, user1#example.com
Bob, user2#example.com
How can I achieve the above?

Answer 1

location is a model object, right?
CSV.generate(options) do |csv|
domain = "example.com"
all.each do |location|
csv << [location.name, "#{location.email_address}##{domain}"]
end
end
Update:
IMO that's cleaner as well. But if you want to keep your version, then I suggest you create a full_email_address method in your Location model which returns something like username#domain.com.
Then, you can vary the columns data later on and easily modify your CSV output. Like so:
class Location << ActiveRecord::Base
def full_email_address
return "" if self.email_address.blank?
domain = "example.com" # or save this as a constant in the class
"#{self.email_address}##{domain}"
end
end
CSV.generate(options) do |csv|
columns = %w{name full_email_address} # add other methods or attributes here
all.each do |location|
csv << columns.map{ |moa| location.public_send(moa) }
end
end

Answer 2

Try this:
CSV.generate(options) do |csv|
columns = %w(name, email_address)
url = "#example.com"
all.each do |location|
row = location.attributes.values_at(*columns)
row[-1] = row[-1] + url
csv << row
end
end
Currently the array written to CSV is ['Joe', 'user1'] + ['#example.com'], so instead of adding url to the attributes array I am adding it to the last attribute.