Question

If I’m using Devise with Rails, how do I go from:
User.all

to an array of email addresses that I can put into a select list?

Something like User.all.email?

Do I need to iterate over the list or is there a more elegant way?

Answer 1

You can do (only Ruby 1.9.2):

User.all.map(&:email)

This is a simple form allowing you to call a single method on each object and return the results in an array.

You can also (both 1.8.7 and 1.9.2):

User.all.map{|u| u.email}

This allows for more complex manipulation, like:

User.all.map{|u| [u.id, u.name + ": " + u.email]

Which of course returns a pair of id and a string containing name and email for each user.

Those methods actually have less to do with devise and more to do with Enumerable