Wagtail body image lookup

models.py

from bs4 import BeautifulSoup
from wagtail.core.fields import RichTextField
from wagtail.core.models import Page


class BlogPost(Page):
    body = RichTextField()
    images = models.ManyToManyField('wagtailimages.Image')

    def save(self, *args, **kwargs):
        super().save(*args, **kwargs)
        self.update_body_images()

    def update_body_images(self):
        parsed_body = BeautifulSoup(self.body, 'html.parser')
        image_ids_unique = set()
        for image in parsed_body.find_all('embed', embedtype='image'):
            image_pk_str = image.get('id', '')
            image_ids_unique.add(int(image_pk_str))

        if not self.has_unpublished_changes:
            # Store unique image ids on the images field so that we can look them up
            self.images.set(image_ids_unique)

    @property
    def body_image_urls(self):
        rendition_filter = 'original'  # Maybe use something different
        return [img.get_rendition(rendition_filter).url for img in self.images.all()]