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Showing content from https://django-versatileimagefield.readthedocs.io/en/latest/model_integration.html below:

Model Integration — django-versatileimagefield 1.0 documentation

The centerpiece of django-versatileimagefield is its VersatileImageField which provides a simple, flexible interface for creating new images from the image you assign to it.

VersatileImageField extends django’s ImageField and can be used as a drop-in replacement for it. Here’s a simple example model that depicts a typical usage of django’s ImageField:

# models.py with `ImageField`
from django.db import models

class ImageExampleModel(models.Model):
    name = models.CharField(
        'Name',
        max_length=80
    )
    image = models.ImageField(
        'Image',
        upload_to='images/testimagemodel/',
        width_field='width',
        height_field='height'
    )
    height = models.PositiveIntegerField(
        'Image Height',
        blank=True,
        null=True
    )
    width = models.PositiveIntegerField(
        'Image Width',
        blank=True,
        null=True
    )

    class Meta:
        verbose_name = 'Image Example'
        verbose_name_plural = 'Image Examples'

And here’s that same model using VersatileImageField instead (see highlighted section in the code block below):

# models.py with `VersatileImageField`
from django.db import models

from versatileimagefield.fields import VersatileImageField

class ImageExampleModel(models.Model):
    name = models.CharField(
        'Name',
        max_length=80
    )
    image = VersatileImageField(
        'Image',
        upload_to='images/testimagemodel/',
        width_field='width',
        height_field='height'
    )
    height = models.PositiveIntegerField(
        'Image Height',
        blank=True,
        null=True
    )
    width = models.PositiveIntegerField(
        'Image Width',
        blank=True,
        null=True
    )

    class Meta:
        verbose_name = 'Image Example'
        verbose_name_plural = 'Image Examples'

Note

VersatileImageField is fully interchangable with django.db.models.ImageField which means you can revert back anytime you’d like. It’s fully-compatible with south so migrate to your heart’s content!

For VersatileImageField fields that are set to blank=True you can optionally specify a placeholder image to be used when its sizers and filters are accessed (like a generic silouette for a non-existent user profile image, for instance).

You have two options for specifying placeholder images:

1. OnDiscPlaceholderImage: If you want to use an image stored on the same disc as your project’s codebase.
2. OnStoragePlaceholderImage: If you want to use an image that can be accessed directly with a django storage class.

Note

All placeholder images are transferred-to and served-from the storage class of their associated field.

A placeholder image that is stored on the same disc as your project’s codebase. Let’s add a new, optional VersatileImageField to our example model to demonstrate:

# models.py
import os

from django.db import models

from versatileimagefield.fields import VersatileImageField
from versatileimagefield.placeholder import OnDiscPlaceholderImage

class ImageExampleModel(models.Model):
    name = models.CharField(
        'Name',
        max_length=80
    )
    image = VersatileImageField(
        'Image',
        upload_to='images/testimagemodel/',
        width_field='width',
        height_field='height'
    )
    height = models.PositiveIntegerField(
        'Image Height',
        blank=True,
        null=True
    )
    width = models.PositiveIntegerField(
        'Image Width',
        blank=True,
        null=True
    )
    optional_image = VersatileImageField(
        'Optional Image',
        upload_to='images/testimagemodel/optional/',
        blank=True,
        placeholder_image=OnDiscPlaceholderImage(
            path=os.path.join(
                os.path.dirname(os.path.abspath(__file__)),
                'placeholder.gif'
            )
        )
    )

    class Meta:
        verbose_name = 'Image Example'
        verbose_name_plural = 'Image Examples'

Note

In the above example the os library was used to determine the on-disc path of an image (placeholder.gif) that was stored in the same directory as models.py.

All placeholder images are automatically saved into the same storage as the field they are associated with into a top-level-on-storage directory named by the VERSATILEIMAGEFIELD_SETTINGS['placeholder_directory_name'] setting (defaults to '__placeholder__' docs).

Placeholder images defined by OnDiscPlaceholderImage will simply be saved into the placeholder directory (defaults to '__placeholder__' docs). The placeholder image defined in the example above would be saved to '__placeholder__/placeholder.gif'.

A placeholder image that can be accessed with a django storage class. Example:

# models.py
from django.db import models

from versatileimagefield.fields import VersatileImageField
from versatileimagefield.placeholder import OnStoragePlaceholderImage

class ImageExampleModel(models.Model):
    name = models.CharField(
        'Name',
        max_length=80
    )
    image = VersatileImageField(
        'Image',
        upload_to='images/testimagemodel/',
        width_field='width',
        height_field='height'
    )
    height = models.PositiveIntegerField(
        'Image Height',
        blank=True,
        null=True
    )
    width = models.PositiveIntegerField(
        'Image Width',
        blank=True,
        null=True
    )
    optional_image = VersatileImageField(
        'Optional Image',
        upload_to='images/testimagemodel/optional/',
        blank=True,
        placeholder_image=OnStoragePlaceholderImage(
            path='images/placeholder.gif'
        )
    )

    class Meta:
        verbose_name = 'Image Example'
        verbose_name_plural = 'Image Examples'

By default, OnStoragePlaceholderImage will look look for this image in your default storage class (as determined by default_storage) but you can explicitly specify a custom storage class with the optional keyword argument storage:

# models.py
from django.db import models

from versatileimagefield.fields import VersatileImageField
from versatileimagefield.placeholder import OnStoragePlaceholderImage

from .storage import CustomStorageCls

class ImageExampleModel(models.Model):
    name = models.CharField(
        'Name',
        max_length=80
    )
    image = VersatileImageField(
        'Image',
        upload_to='images/testimagemodel/',
        width_field='width',
        height_field='height'
    )
    height = models.PositiveIntegerField(
        'Image Height',
        blank=True,
        null=True
    )
    width = models.PositiveIntegerField(
        'Image Width',
        blank=True,
        null=True
    )
    optional_image = VersatileImageField(
        'Optional Image',
        upload_to='images/testimagemodel/optional/',
        blank=True,
        placeholder_image=OnStoragePlaceholderImage(
            path='images/placeholder.gif',
            storage=CustomStorageCls()
        )
    )

    class Meta:
        verbose_name = 'Image Example'
        verbose_name_plural = 'Image Examples'

Placeholder images defined by OnStoragePlaceholderImage will be saved into the placeholder directory (defaults to '__placeholder__' docs) within the same folder heirarchy as their original storage class. The placeholder image used in the example above would be saved to '__placeholder__/image/placeholder.gif.

WebP images are fully supported across the whole library and should act like any other image type.

Note

If you are uploading a WebP image in a Django<2.2, you need to provide explicit values for both, width and height fields. This behavior has been fixed in the following Django versions. Check Django#10331 for more info.

from someapp.models import ImageExampleModel

# Django OK
ImageExampleModel.objects.create(
    image="python-logo.webp",
    width=580,
    height=164
)

# Django>=2.2 OK. Will through an error in earlier versions.
ImageExampleModel.objects.create(
    image="python-logo.webp",
    width=0,
    height=0
)

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