Something wrong with my validates in Rail 4? - ruby-on-rails

Question

I want to show my validates in "users.rb". Can anyone help?. I've watched some video tutorial then found myself that was not "define new" but I did not know how to resolve this.
user_controller.rb
class UsersController::ApplicationController
def login
if params[:user]
#notice = "LOGIN FAILED"
#email = params[:user][:mailaddress]
#password = params[:user][:password]
#user = User.find_by(mailaddress: #email)
if #user
#member = Member.find_by(user_id: #user.id)
if #member
#hash = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha256'), #member.salt, #password)
if #hash == #member.hashed_password
# SUCCESS
#notice = "LOGIN SUCCESSFULL"
end
end
end
end
end
end
-------
user.rb
class User::ActiveRecord::Base
has_one :member
validates :mailaddress, presence: {message: "Email need inputed"} #want to show this validates in login.html.haml
end
---------------
login.html.haml
= form_for(:user, url:login_path) do |f|
%div.login
= f.label "Email", class:'control-label'
= f.email_field :mailaddress, class: 'form-control'
= f.label "Password", class: 'control-label'
= f.password_field :password, class: 'control-label'
%div.btn-are
= f.submit 'Finish', class: 'btn'

Answer 1

Validations works only on model create/update but not on some actions like login.
Please see the docs for more info.
You can show flash if some params are missing
user_controller.rb
class UsersController::ApplicationController
def login
if params[:user]
unless params[:user][:mailaddress]
flash[:error] = "Email is required"
render :your_login_path
end
#notice = "LOGIN FAILED"
#email = params[:user][:mailaddress]
#password = params[:user][:password]
#user = User.find_by(mailaddress: #email)
if #user
#member = Member.find_by(user_id: #user.id)
if #member
#hash = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha256'), #member.salt, #password)
if #hash == #member.hashed_password
# SUCCESS
#notice = "LOGIN SUCCESSFULL"
end
end
end
end
end
end
- flash.each do |name, msg|
= content_tag :div, msg, class: name
= form_for(:user, url:login_path) do |f|
%div.login
= f.label "Email", class:'control-label'
= f.email_field :mailaddress, class: 'form-control'
= f.label "Password", class: 'control-label'
= f.password_field :password, class: 'control-label'
%div.btn-are
= f.submit 'Finish', class: 'btn'
The code above is untested, but should work.
Here is the flash documentation
But I'm strongly recommend to use devise to perform sign_in/sign_up of users.