generate unique username (omniauth + devise) - ruby-on-rails

Question

I have an app with user authentication with devise + omniauth.
In my model that username in my app is unique. I dont want duplicate username in my app.
Some users in facebook has not a defined username in his profile.
I want generate an unique username if the user has not username defined in facebook.
For example for generate password I have this:
:password => Devise.friendly_token[0,20]
How can I generate a unique username for my app if the facebook user has not username in facebook?
Thank you

Answer 1

You can create a nice readable username (eg generated from the first part of the email) and then ensure it is unique by adding numbers until it is. eg
#in User
def get_unique_login
login_part = self.email.split("#").first
new_login = login_part.dup
num = 2
while(User.find_by_login(new_login).count > 0)
new_login = "#{login_part}#{num}"
num += 1
end
new_login
end
One problem here is that someone could potentially bag that login inbetween you getting it and you saving it. So, maybe it's best to combine it into a before_create filter:
#in User
before_create :ensure_login_uniqueness
def ensure_login_uniqueness
if self.login.blank? || User.find_by_login(self.login).count > 0
login_part = self.email.split("#").first
new_login = login_part.dup
num = 2
while(User.find_by_login(new_login).count > 0)
new_login = "#{login_part}#{num}"
num += 1
end
self.login = new_login
end
end

Answer 2

You can take a part of email before the # sign and add there smth like user_id, or just take the email itself. Or you can combine somehow the first and last names from the fb response.

Answer 3

Here is how i created Login with combination of first name and last name field.. Improvements on this code is welcome.
before_create :ensure_login_uniqueness
def ensure_login_uniqueness
if self.login.blank?
self.name = self.first_name + " " + self.last_name
firstnamePart = self.first_name.downcase.strip.gsub(' ', '').gsub(/[^\w-]/, '')
lastnamePart = self.last_name.downcase.strip.gsub(' ', '').gsub(/[^\w-]/, '')
login_part = firstnamePart+lastnamePart
new_login = login_part.dup
num = 1
while(User.where(:login => new_login).count > 0)
new_login = "#{login_part}#{num}"
num += 1
end
self.login = new_login
end
end

Answer 4

It did not work for me,but change:
while(User.find_by_login(new_login).count > 0)
to
while(User.where(login: new_login).count > 0)

Answer 5

Here's my methods that I use for Facebook
def ensure_username_uniqueness
self.username ||= self.email.split("#").first
num = 2
until(User.find_by(username: self.username).nil?)
self.username = "#{username_part}#{num}"
num += 1
end
end
def self.from_omniauth(auth)
where(provider: auth.provider, uid: auth.uid).first_or_create do |user|
user.email = auth.info.email
user.password = Devise.friendly_token[0,20]
user.username = auth.info.name.downcase.gsub(" ", "")
user.username = user.username[0..29] if user.username.length > 30
user.ensure_username_uniqueness
end
end

Answer 6

Here is the way how you can generate "username" from "full name"
def self.generate_username(full_name)
generated = ActiveSupport::Inflector.transliterate(full_name) # change ñ => n
.downcase # only lower case
.strip # remove spaces around the string
.gsub(/[^a-z]/, '_') # any character that is not a letter or a number will be _
.gsub(/\A_+/, '') # remove underscores at the beginning
.gsub(/_+\Z/, '') # remove underscores at the end
.gsub(/_+/, '_')
taken_usernames = User
.where("username LIKE ?", "#{generated}%")
.pluck(:username)
# username if it's free
return generated unless taken_usernames.include?(generated)
count = 2
while true
# username_2, username_3...
new_username = "#{generated}_#{count}"
return new_username if ! taken_usernames.include?(new_username)
count += 1
end
end