Ruby on Rails - basic form submission - mysql

Question

I have been working on PHP. Presently trying to learn Ruby on Rails. I am learning Rails online, for now I am badly stuck on Sign-up or can say a form submission page. Sorry if it's too silly.
Error is:
undefined method new for nil:NilClass
Here is the code:
users_controller.rb
class UsersController < ApplicationController
def new
#user= User.new
end
def create
#user.new(params[:user])
if #user.save
flash[:notice]= "you signed up successfully"
flash[:color]= "valid"
else
flash[:notice]= "failed"
flash[:color]="invalid"
end
render "new"
end
end
new.html.erb
<% page_title="Signup" %>
<div class="Sign_Form">
<h1>Sign up</h1>
<%= form_for(:user, :url => {:controller => 'users', :action => 'create'}) do |f| %>
<p> Username:</br> <%= f.text_field :username%> </p>
<p> Email:</br> <%= f.text_field :email%> </p>
<p> Password:</br> <%= f.password_field :password%></p>
<p> Password Confirmation:</br> <%= f.password_field :password_confirmation%> </p>
<%= f.submit :Signup %>
<% end %>
<% if #user.errors.any? %>
<ul class="Signup_Errors">
<% for message_error in #user.errors.full_messages %>
<li>* <%= message_error %></li>
<% end %>
</ul>
<% end %>
</div>
user.rb
class User < ActiveRecord::Base
attr_accessor :password
EMAIL_REGEX = /^[A-Z0-9._%+-]+#[A-Z0-9.-]+\.[A-Z]{2,4}$/i
validates :username, :presence => true, :uniqueness => true, :length => { :in => 3..20 }
validates :email, :presence => true, :uniqueness => true #:format => EMAIL_REGEX
validates :password, `enter code here`:presence =>true #:confirmation => true #password_confirmation attr
validates_length_of :password, :in => 6..20, :on => :create
end

Answer 1

In your users_controller > create, you put capital letter on User param.
For your case, it should be all lower case params[:user].
Side note, it actually depends on your attribute name you set on the form in the first place.
Edit:
In addition of that you should put #user = User.new(params[:user])

Answer 2

First thing you should create new object of User class
Second pass correct params key
change first line in create method to
#user = User.new(params[:user])
So the changed code will look like this:
class UsersController < ApplicationController
def new
#user= User.new
end
def create
#user = User.new(params[:user])
if #user.save
flash[:notice]= "you signed up successfully"
flash[:color]= "valid"
else
flash[:notice]= "failed"
flash[:color]="invalid"
end
render "new"
end
end

Answer 3

change #user.new(params[:user]) to #user = User.new(params[:user]) I creates #user but it is not saved to database yet. On the line below #user.save that is when it gets saved. And remove render new because it will render the template with out setting the variables that the template needs. instead use redirect_to :new that will send the user to new and also set the variables needed

Answer 4

I guess you need to allow the params of User model in the User controller so as to avoid the forbidden error message as mentioned here. Please note that this is Rails feature as mentioned
Rails has several security features that help you write secure applications, and you're running into one of them now. This one is called strong parameters, which requires us to tell Rails exactly which parameters are allowed into our controller actions.
Thanks