Parse email addresses for “from” and “to” fields i

Question

In an email, it looks like a "from" or "to" field can contain one or more addresses, each address can be like "[e-mail]" or "John D Jr <[e-mail]>"

So a "from" field can look like any of the following:

"[e-mail]"

"[e-mail], Bob Blue <[e-mail]>"

"Abe Allen <[e-mail]>, [e-mail]"

"Abe Allen <[e-mail]>, Bob Blue <[e-mail]>"

"Abe Allen <[e-mail]>, Bob Blue <[e-mail]>, [e-mail]"

and so on.

I want to parse these fields, extracting each address' email if it's valid, and the name if it's present. Since I'm not familiar with the email standard, I may be missing some cases of what address fields can look like. Is there a Ruby library that can do this?

Answer 1

I don't know of a library, but if you are trying to get a list of the emails you could do the following yourself. (Long winded on purpose)

@a = "Abe Allen <[e-mail]>, Bob Blue <[e-mail]>, [e-mail]"
b = @a.split(',') #=> ["Abe Allen <[e-mail]>", " Bob Blue <[e-mail]>", " [e-mail]"] 
c = b.collect{|x| x[/<(.*?)>|^([^<>]*)$/]} #=> ["<[e-mail]>", "<[e-mail]>", " [e-mail]"] 
d = c.gsub(/[<>]/,'') #=> ["[e-mail]", "[e-mail]", " [e-mail]"] 

If you want to match their names and email addresses, you will need something else.

Also, this won't work if there are '<' or '>' in the email address, but that's pretty uncommon.

Answer 2

Yes, there's a gem for this; it's called mail.

require 'mail'

addresses = []
raw_addresses = Mail::AddressList.new("Abe Allen <[e-mail]>, Bob Blue <[e-mail]>, [e-mail]")

raw_addresses.addresses.each do |a|  
  address = {}

  address[:address] = a.address
  address[:name]    = a.display_name if a.display_name.present?

  addresses << address      
end

Answer 3

Assuming your data follows the examples you gave, this should work:

def extract_emails(string)
  string.split(', ').map do |user_string|
    if user_string.include? '<'
      user_string =~ /^([^<]*)<([^>]*)>$/
      {user: $1.strip, email: $2}
    else
      {user: nil, email: user_string}
    end
  end
end

extract_emails "[e-mail]"                                          
# => [{:user=>nil, :email=>"[e-mail]"}]

extract_emails "[e-mail], Bob Blue <[e-mail]>"                      
# => [{:user=>nil, :email=>"[e-mail]"}, {:user=>"Bob Blue", :email=>"[e-mail]"}]

extract_emails "Abe Allen <[e-mail]>, [e-mail]"                     
# => [{:user=>"Abe Allen", :email=>"[e-mail]"}, {:user=>nil, :email=>"[e-mail]"}]

extract_emails "Abe Allen <[e-mail]>, Bob Blue <[e-mail]>"          
# => [{:user=>"Abe Allen", :email=>"[e-mail]"}, {:user=>"Bob Blue", :email=>"[e-mail]"}]

extract_emails "Abe Allen <[e-mail]>, Bob Blue <[e-mail]>, [e-mail]" 
# => [{:user=>"Abe Allen", :email=>"[e-mail]"}, {:user=>"Bob Blue", :email=>"[e-mail]"}, {:user=>nil, :email=>"[e-mail]"}]