Custom image models¶

The Image model can be customized, allowing additional fields to be added to images.

To do this, you need to add two models to your project:

The image model itself that inherits from wagtail.images.models.AbstractImage. This is where you would add your additional fields
The renditions model that inherits from wagtail.images.models.AbstractRendition. This is used to store renditions for the new model.

Here’s an example:

# models.py
from django.db import models

from wagtail.images.models import Image, AbstractImage, AbstractRendition


class CustomImage(AbstractImage):
    # Add any extra fields to image here

    # To add a caption field:
    # caption = models.CharField(max_length=255, blank=True)

    admin_form_fields = Image.admin_form_fields + (
        # Then add the field names here to make them appear in the form:
        # 'caption',
    )


class CustomRendition(AbstractRendition):
    image = models.ForeignKey(CustomImage, on_delete=models.CASCADE, related_name='renditions')

    class Meta:
        unique_together = (
            ('image', 'filter_spec', 'focal_point_key'),
        )

Then set the WAGTAILIMAGES_IMAGE_MODEL setting to point to it:

WAGTAILIMAGES_IMAGE_MODEL = 'images.CustomImage'

Migrating from the builtin image model¶

When changing an existing site to use a custom image model, no images will be copied to the new model automatically. Copying old images to the new model would need to be done manually with a data migration.

Any templates that reference the builtin image model will still continue to work as before but would need to be updated in order to see any new images.

Referring to the image model¶

wagtail.images.get_image_model()¶: Get the image model from the WAGTAILIMAGES_IMAGE_MODEL setting. Useful for developers making Wagtail plugins that need the image model. Defaults to the standard wagtail.images.models.Image model if no custom model is defined.

wagtail.images.get_image_model_string()¶: Get the dotted app.Model name for the image model as a string. Useful for developers making Wagtail plugins that need to refer to the image model, such as in foreign keys, but the model itself is not required.

Overriding the upload location¶

The following methods can be overridden on your custom Image or Rendition models to customize how the original and rendition image files get stored.

class wagtail.images.models.AbstractImage¶

get_upload_to(filename)¶: Generates a file path in the “original_images” folder. Ensuring ASCII characters and limiting length to prevent filesystem issues during uploads.

class wagtail.images.models.AbstractRendition¶

get_upload_to(filename)¶: Generates a file path within the “images” folder by combining the folder name and the validated filename.

Refer to the Django FileField.upload_to function to further understand how the function works.