before_validation method not working - ruby-on-rails

Question

I am a newB in rails and I am working on a project and wanted to remove trailing and leading white spaces from username and email. So I created a method in user model
class User < ActiveRecord::Base
include CarrierWave::MiniMagick
#removes the white spaces before validating the data
before_validation :strip_whitespace, :only => [:name,:email]
#data validations
validates :email, :presence =>true, :uniqueness => {case_sensitive: false}, :format => { :with=> /([a-zA-Z0-9_\-\.]+)#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)/, :message => "please enter a valid e-mail" }
validates :name, :presence=>true
validates :password ,:presence =>true, :confirmation=> true #, :length =>{ :minimum=>6, :maximum=>30}, :format=>{:with=>/(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{6,30}/}
#for the image
mount_uploader :image, ImageUploader
#for the password
has_secure_password
#associations
has_many :issues
has_many :comments
end
def strip_whitespace
self.email = self.email.squish
self.name = self.name.squish
end
when I enter user information in Users.create action, the leading and trailing spaces are removed, But when I login from my sessions controller, the leading and trailing spaces are not removed and hence it shows me an error.
Please help
Code for the users controller
class UsersController < ApplicationController
before_action :not_logged_in?, :only => [:new]
def new
#user=User.new
end
def create
#user = User.new(user_params)
if #user.save
sign_in #user
RegistrationsMailer.welcome_email(#user).deliver
flash[:success] = 'you are successfully registered'
redirect_to :controller => 'users' , :action => 'show', :id => #user.id
else
render 'new'
end
end
def show
#user=User.find(params[:id])
end
def edit
#user = User.find(params[:id])
end
def update
#user = User.find(params[:id])
if #user.update_attributes(user_params)
redirect_to #user
else
render 'edit'
end
end
protected
def user_params
params.require(:user).permit(:name,:email,:password,:image)
end
end
code for sessions controller
class SessionsController < ApplicationController
def new
end
def create
#user = User.find_by_email(params[:sessions][:email])
if #user && #user.authenticate(params[:sessions][:password])
sign_in #user
redirect_to #user
else
flash.now[:error] = 'Invalid email or password'
render 'new'
end
end
def destroy
end
end
Please help

Answer 1

According to When does Validation happen?
The following methods trigger validations, and will save the object to the database only if the object is valid:
create
create!
save
save!
update
update!
When you are creating or destroying a new session, you don't actually call any of those methods on the User model so validations won't be called.
But since your database has the squished values, you need to modify your create action in the SessionsController to squish the passed in params.
def create
#user = User.find_by_email(params[:sessions][:email].squish)
if #user && #user.authenticate(params[:sessions][:password].squish)
sign_in #user
redirect_to #user
else
flash.now[:error] = 'Invalid email or password'
render 'new'
end
end