lib/common/user.rb

   1 require 'common/domain'
   2 require 'common/errors'
   3
   4 # A class representing a syntactically valid user; that is, an email
   5 # address. Once constructed, you can be sure that it's valid.
   6 #
   7 class User
   8
   9   # @localpart is a String containing the "user" part of "user@domain".
  10   @localpart = nil
  11
  12   # @domain contains a {Domain} object representing the domain part of
  13   # "user@domain".
  14   @domain = nil
  15
  16
  17   # Obtain the {Domain} object corresponding to this User.
  18   #
  19   # @return [Domain] the domain corresponding to this User.
  20   #
  21   def domain()
  22     return @domain
  23   end
  24
  25
  26   # Obtain the domain part of this User object as a string.
  27   #
  28   # @return [String] a String representation of this User's domain.
  29   #
  30   def domainpart()
  31     return @domain.to_s()
  32   end
  33
  34
  35   # Initialize this User object. If either of the local/domain parts
  36   # is invalid, then either an {InvalidUserError} or an {InvalidDomainError}
  37   # will be raised containing the reason why that part is invalid.
  38   #
  39   # @param username [String] an email address from which to construct
  40   #   this User.
  41   #
  42   def initialize(username)
  43
  44     if not username.is_a?(String)
  45       msg =  'username must be a String '
  46       msg += "but a #{username.class.to_s()} was given"
  47       raise InvalidUserError.new(msg)
  48     end
  49
  50     parts = username.split('@')
  51
  52     if parts.length() < 2 then
  53       msg = "the username #{username} does not contain an '@' symbol"
  54       raise InvalidUserError.new(msg)
  55     end
  56
  57     localpart = parts[0]
  58
  59     if localpart.length() > 64 then
  60       msg = "the local part of #{username} cannot have more than 64 characters"
  61       raise InvalidUserError(msg)
  62     end
  63
  64     if localpart.empty? then
  65       msg = "the local part of #{username} cannot be empty"
  66       raise InvalidUserError.new(msg)
  67     end
  68
  69     @localpart = localpart
  70     @domain = Domain.new(parts[1])
  71   end
  72
  73
  74   # Obtain the "user" part of this User object as a String.
  75   #
  76   # @return [String] the "user" part of this User's "user@domain"
  77   #   address.
  78   #
  79   def localpart()
  80     return @localpart
  81   end
  82
  83
  84   # Convert this User to an email address string.
  85   #
  86   # @return [String] an email address String constructed from this
  87   #   user's local and domain parts.
  88   #
  89   def to_s()
  90     return @localpart + '@' + @domain.to_s()
  91   end
  92
  93
  94   # Check if this User is equal to some other User. The comparison
  95   # is based on their String representations.
  96   #
  97   # @param other [User] the User object to compare me to.
  98   #
  99   # @return [Boolean] If *self* and *other* have equal String
 100   #   representations, then true is returned. Otherwise, false is
 101   #   returned.
 102   #
 103   def ==(other)
 104     return self.to_s() == other.to_s()
 105   end
 106
 107
 108   # Compare two User objects for sorting purposes. The comparison is
 109   # is based on their String representations.
 110   #
 111   # @param other [User] the User object to compare me to.
 112   #
 113   # @return [0,1,-1] a trinary indicator of how *self* relates to *other*,
 114   #   obtained by performing the same comparison on the String
 115   #   representations of *self* and *other*.
 116   #
 117   def <=>(other)
 118     return self.to_s() <=> other.to_s()
 119   end
 120 end