How can i return some message if before_validation method is false by Sinatra - ruby

Question

I want to return some message that tell the user their password is not match with the confirm password field.
This is my code
post '/signup' do
user = User.new(params[:user])
if user.create_user
"#{user.list}"
else
"password not match"
end
end
require 'bcrypt'
class User < ActiveRecord::Base
include BCrypt
# This is Sinatra! Remember to create a migration!
attr_accessor :password
validates :username, presence: true, uniqueness: true
validates :email, :format => { :with => /\A[\w+\-.]+#[a-z\d\-]+(\.[a-z]+)*\.[a-z]+\z/i ,
:message => "Email wrong format" }
validates :email, uniqueness: true,presence: true
validates :encrypted_password, presence: true
validates :encrypted_password, length: { minimum: 6 }
before_validation :checking_confirm_password
def initialize(signup = {})
##signup = signup
super()
#username = signup["username"]
#email = signup["email"]
#password = signup["password"]
#confirm_password = signup["confirm_password"]
end
def create_user
p_p = Password.create(#password)
p_h ||= Password.new(p_p)
user_hash = {:username => #username,:email => #email, :encrypted_password => p_h}
return User.create(user_hash)
end
def list
User.all
end
private
def checking_confirm_password
if #password != #confirm_password
return false
end
end
end
So how can i specific the message that will send back to the user,
if their password is not match or the validation fail before create the dada?
Thanks!

Answer 1

The validations populate #user.errors with all validation errors with all validation errors by field, so you can easily return all validation errors at once like so:
post '/signup' do
user = User.new(params[:user])
if user.create_user
"#{user.list}"
else
user.errors.full_messages
end
end
Have a look at: http://edgeguides.rubyonrails.org/active_record_validations.html#working-with-validation-errors