cnk/models.py

## models.py
from django.db import models


class RobotsTxtMixin(models.Model):
    """
    Always mix this class in BEFORE wagtailcore.Page. Otherwise, its override of get_sitemap_urls() won't get called.
    """

    hide_from_search_engines = models.BooleanField(
        default=False,
        help_text="Prevent this page from being indexed by search engines. "
                  "You must enable this setting before you publish the page for it to have the desired effect."
    )

    class Meta:
        abstract = True

    def get_sitemap_urls(self, request=None):
        """
        Exclude from the XML sitemap all Pages which have hide_from_search_engines enabled.
        """
        if self.hide_from_search_engines:
            return []
        else:
            # Every class that derives from RobotsTxtMixin also derives from Page, which has get_sitemap_urls().
            # noinspection PyUnresolvedReferences
            return super().get_sitemap_urls(request)

## template.html
<head>
  {% if self.hide_from_search_engines %}
    <meta name="robots" content="noindex">
  {% endif %}
</head>
	from django.db import models


	class RobotsTxtMixin(models.Model):
	"""
	Always mix this class in BEFORE wagtailcore.Page. Otherwise, its override of get_sitemap_urls() won't get called.
	"""

	hide_from_search_engines = models.BooleanField(
	default=False,
	help_text="Prevent this page from being indexed by search engines. "
	"You must enable this setting before you publish the page for it to have the desired effect."
	)

	class Meta:
	abstract = True

	def get_sitemap_urls(self, request=None):
	"""
	Exclude from the XML sitemap all Pages which have hide_from_search_engines enabled.
	"""
	if self.hide_from_search_engines:
	return []
	else:
	# Every class that derives from RobotsTxtMixin also derives from Page, which has get_sitemap_urls().
	# noinspection PyUnresolvedReferences
	return super().get_sitemap_urls(request)
	<head>
	{% if self.hide_from_search_engines %}
	<meta name="robots" content="noindex">
	{% endif %}
	</head>