title: django allauth custom login with additional check apart from email and password
body: <p>Here is my Custom login form from Allauth</p>
  
  <pre><code>class CustomLoginForm(LoginForm):
      def __init__(self,*args,**kwargs):
          super(CustomLoginForm,self).__init__(*args,**kwargs)
          self.fields['login'].widget.attrs['class'] = 'form-control'
          self.fields['password'].widget.attrs['class'] = 'form-control' 
  
      def login(self, *args, **kwargs):
          return super(CustomLoginForm, self).login(*args, **kwargs)
  </code></pre>
  
  <p>The above works well when I use only Email and Password, and I would like to check another option, for example <strong>custom_field</strong> is <strong>true</strong></p>
  
  <p>I saw this reference, <a href="https://django-allauth.readthedocs.io/en/latest/forms.html#login-allauth-account-forms-loginform" rel="nofollow noreferrer">https://django-allauth.readthedocs.io/en/latest/forms.html#login-allauth-account-forms-loginform</a> and it says add your processing, but I struck with how to do it.. Any ideas?</p>