Rspec, capybara getting started issues - ruby

Question

I have have started with simple example of Rspec,Capybara. I have come across few issues. This issues are probably because I have experience with cucumber and page_object gem, but here I am using capybara and Site_prism gem.
I have tried:
my_example_spec.rb
require_relative 'Support/spec_helper'
require_relative 'pages/login_page'
describe 'My behaviour' do
it 'should do something'do
#login_page = LoginPage.new
#login_page.load
#login_page.login('autouser','password')
end
end
and login_page.rb
class LoginPage < SitePrism::Page
set_url "/login"
element :username, "input[id='username']"
element :password, "input[id='password']"
element :submit, "input[id='submit']"
def login(username,password)
#login_page.username.set username
#login_page.password.set password
#login_page.submit.click
end
end
Issues are:
When I run my_example_spec.rb it gives error
Testing started at ...
Run options: include {:full_description=>/My\ behaviour\ should\ do\ something/}
NoMethodError: undefined method `username' for nil:NilClass
./pages/login_page.rb:10:in `login'
./my_example_spec.rb:11:in `block (2 levels) in <top (required)>'
-e:1:in `load'
-e:1:in `<main>'
Shouldn't it be on(LoginPage).login (autouser, password). It should navigate to the page and run login method. It is how it works in page_object gem whats the equivalent of site_prism gem

Answer 1

The login method in your LoginPage class should be
def login(username,password)
username.set username
password.set password
submit.click
end
#login_page is not an instance variable of the LoginPage class so it is not accessible inside the class. It's also not necessary inside the class since you're already inside the class.