old_contents: from flask import Blueprint, render_template
  from flask_security import login_required
  
  admin = Blueprint('admin', __name__)
  
  
  @admin.route('/')
  @admin.route('/index')
  @login_required
  def index():
      return render_template('admin/index.html', title='Admin')
  
new_contents: from flask import Blueprint, render_template, redirect, url_for
  from flask_security import current_user
  
  admin = Blueprint('admin', __name__)
  
  
  @admin.route('/')
  @admin.route('/index')
  def index():
      return render_template('admin/index.html', title='Admin')
  
  
  @admin.before_request
  def require_login():
      if not current_user.is_authenticated:
          return redirect(url_for('security.login', next='admin'))
  
subject: Move admin authentication into before_request handler