creating name helper, to split first and last names apart - ruby-on-rails

Question

I'm looking for some help on how to take an attribute and process it through a method to return something different. But I've never done this before and I' not sure where to start. I thought trying to change a name:string attribute from "George Washington" or "John Quincy Adams" into first names only "George" and "John".
I thought maybe a helper method would be best, such as
users_helper.rb
def first_name
end
and then call #user.name.first_name, would this be initially how it would work? Can someone explain where I'd go next to be able to pass #user.name into the method? I've seen things like this but don't quite understand it the parenthesis...
def first_name(name)
puts name
end
Could someone breakdown how rails/ruby does this type of thing? Thanks a lot!

Answer 1

Some people have more than two names, such as "John Clark Smith". You can choose to treat them as:
(1) first_name: "John", last_name: "Smith"
def first_name
if name.split.count > 1
name.split.first
else
name
end
end
def last_name
if name.split.count > 1
name.split.last
end
end
(2) first_name: "John Clark", last_name: "Smith"
def first_name
if name.split.count > 1
name.split[0..-2].join(' ')
else
name
end
end
def last_name
if name.split.count > 1
name.split.last
end
end
(3) first_name: "John", last_name: "Clark Smith"
def first_name
name.split.first
end
def last_name
if name.split.count > 1
name.split[1..-1].join(' ')
end
end
The above examples assume that if the name contains less than 2 words then it is a first name.

Answer 2

The parentheses (which are optional) enclose the parameter list.
def first_name(full_name)
full_name.split(" ")[0]
end
This assumes the parameter is not nil.
> puts first_name "Jimmy McKickems"
Jimmy
> puts first_name "Jeezy"
Jeezy
But this is not a string method, as your assumption is now:
#user.full_name.first_name # Bzzt.
Instead:
first_name #user.name
This could be wrapped up in the model class itself:
class User < ActiveRecord
# Extra stuff elided
def first_name
self.full_name.blank? ? "" : self.full_name.split(" ")[0]
end
end
The extra code checks to see if the name is nil or whitespace (blank? comes from Rails). If it is, it returns an empty string. If it isn't, it splits it on spaces and returns the first item in the resulting array.

Answer 3

In case you are looking to split only once and provide both parts this one liner will work:
last_name, first_name = *name.reverse.split(/\s+/, 2).collect(&:reverse)
Makes the last word the last name and everything else the first name. So if there is a prefix, "Dr.", or a middle name that will be included with the first name. Obviously for last names that have separate words, "Charles de Gaulle" it won't work but handling that is much harder (if not impossible).

Answer 4

Use Ruby's Array#pop
For my needs I needed to take full names that had 1, 2, 3 or more "names" in them, like "AUSTIN" or "AUSTIN J GILLEY".
The Helper Method
def split_full_name_into_first_name_and_last_name( full_name )
name_array = full_name.split(' ') # ["AUSTIN", "J", "GILLEY"]
if name_array.count > 1
last_name = name_array.pop # "GILLEY"
first_name = name_array.join(' ') # "AUSTIN J"
else
first_name = name_array.first
last_name = nil
end
return [ first_name, last_name ] # ["AUSTIN J", "GILLEY"]
end
Using It
split_full_name_into_first_name_and_last_name( "AUSTIN J GILLEY" )
# => ["AUSTIN J", "GILLEY"]
split_full_name_into_first_name_and_last_name( "AUSTIN" )
# => ["AUSTIN", nil]
And you can easily assign the first_name and last_name with:
first_name, last_name = split_full_name_into_first_name_and_last_name( "AUSTIN J GILLEY" )
first_name
# => "AUSTIN J"
last_name
# => "GILLEY"
You can modify from there based on what you need or want to do with it.

Answer 5

For the syntax you're asking for (#user.name.first_name) Rails does a lot of this sort of extension by adding methods to base types, in your example you could do this through defining methods on the String class.
class String
def given; self.split(' ').first end
def surname; self.split(' ').last end
end
"Phileas Fog".surname # 'fog'
Another way to do something like this is to wrap the type you whish to extend, that way you can add all the crazy syntax you wish without polluting more base types like string.
class ProperName < String
def given; self.split(' ').first end
def surname; self.split(' ').last end
end
class User
def name
ProperName.new(self.read_attribute(:name))
end
end
u = User.new(:name => 'Phileas Fog')
u.name # 'Phileas Fog'
u.name.given # 'Phileas'
u.name.surname # 'Fog'

Answer 6

Just as complement of great Dave Newton's answer, here is what would be the "last name" version:
def last_name
self.full_name.blank? ? "" : self.full_name.split(" ")[-1]
end

Answer 7

making it simple
class User < ActiveRecord::Base
def first_name
self.name.split(" ")[0..-2].join(" ")
end
def last_name
self.name.split(" ").last
end
end
User.create name: "John M. Smith"
User.first.first_name
# => "John M."
User.first.last_name
# => "Smith"
Thanks

Answer 8

def test_one(name)
puts "#{name.inspect} => #{yield(name).inspect}"
end
def tests(&block)
test_one nil, &block
test_one "", &block
test_one "First", &block
test_one "First Last", &block
test_one "First Middle Last", &block
test_one "First Middle Middle2 Last", &block
end
puts "First name tests"
tests do |name|
name.blank? ? "" : name.split(" ").tap{|a| a.pop if a.length > 1 }.join(" ")
end
puts "Last name tests"
tests do |name|
name.blank? ? "" : (name.split(" ").tap{|a| a.shift }.last || "")
end
Output:
First name tests
nil => ""
"" => ""
"First" => "First"
"First Last" => "First"
"First Middle Last" => "First Middle"
"First Middle Middle2 Last" => "First Middle Middle2"
Last name tests
nil => ""
"" => ""
"First" => ""
"First Last" => "Last"
"First Middle Last" => "Last"
"First Middle Middle2 Last" => "Last"