django-stdimage 1.1.3

Django Standarized Image Field

Django Standarized Image Field

Django Field that implement the following features:

• Django-Storages compatible (S3)

• Python 2 & 3 support

• Django 1.5 and later support

• Resize images to different sizes

• Access thumbnails on model level, no template tags required

• Preserves original image

• Restrict accepted image dimensions

• Rename files to a standardized name (using a callable upload_to)

Installation

Simply install the latest stable package using the command

easy_install django-stdimage or pip django-stdimage

and add 'stdimage' to INSTALLED_APPs in your settings.py, that’s it!

Usage

StdImageField works just like Django’s own ImageField except that you can specify different sized variations.

Variations

Variations are specified withing a dictionary. The key will will be the attribute referencing the resized image. A variation can be defined both as a tuple or a dictionary.

Example:

from stdimage.models import StdImageField

class MyModel(models.Model):
    # works just like django's ImageField
    image = StdImageField(upload_to='path/to/img')

    # creates a thumbnail resized to maximum size to fit a 100x75 area
    image = StdImageField(upload_to='path/to/img', variations={'thumbnail': {'with': 100, 'height': 75}})

    # is the same as dictionary-style call
    image = StdImageField(upload_to='path/to/img', variations={'thumbnail': (100, 75)})

    # creates a thumbnail resized to 100x100 croping if necessary
    image = StdImageField(upload_to='path/to/img', variations={
       'thumbnail': {"width": 100, "height": 100, "crop":True}
    })

    ## Full ammo here. Please note all the definitions below are equal
    image = StdImageField(upload_to=upload_to, blank=True, variations={
        'large': (600, 400),
        'thumbnail': (100, 100, True),
        'medium': (300, 200),
    })

For using generated variations in templates use “myimagefield.variation_name”.

Example:

<a href="{{ object.myimage.url }}"><img alt="" src="{{ object.myimage.thumbnail.url }}"/></a>

Utils

By default StdImageField stores images without modifying the file name. If you want to use more consistent file names you can use the build in upload callables.

Example:

from stdimage.utils import UploadToUUID, UploadToClassNameDir, UploadToAutoSlug, UploadToAutoSlugClassNameDir

class MyClass(models.Model)
    # Gets saved to MEDIA_ROOT/myclass/#FILENAME#.#EXT#
    image1 = StdImageField(upload_to=UploadToClassNameDir())

    # Gets saved to MEDIA_ROOT/myclass/pic.#EXT#
    image2 = StdImageField(upload_to=UploadToClassNameDir(name='pic'))

    # Gets saved to MEDIA_ROOT/images/#UUID#.#EXT#
    image3 = StdImageField(upload_to=UploadToUUID(path='images'))

    # Gets saved to MEDIA_ROOT/myclass/#UUID#.#EXT#
    image4 = StdImageField(upload_to=UploadToClassNameDirUUID())

    # Gets save to MEDIA_ROOT/images/#SLUG#.#EXT#
    image5 = StdImageField(upload_to=UploadToAutoSlug(path='images))

    # Gets save to MEDIA_ROOT/myclass/#SLUG#.#EXT#
    image6 = StdImageField(upload_to=UploadToAutoSlugClassNameDir())

Validators

The StdImageField doesn’t implement any size validation. Validation can be specified using the validator attribute and using a set of validators shipped with this package. Validators can be used for both Forms and Models.

Example:

from stdimage.validators import UploadToUUID, UploadToClassNameDir, UploadToAutoSlug, UploadToAutoSlugClassNameDir

class MyClass(models.Model)
    image1 = StdImageField(validators=MinSizeValidator(800, 600))
    image2 = StdImageField(validators=MaxSizeValidator(1028, 768))

CAUTION: The MaxSizeValidator should be used with caution. As storage isn’t expensive, you shouldn’t restrict upload dimensions. If you seek prevent users form overflowing your memory you should restrict the HTTP upload body size.

Deleting images

Django dropped support. for automated deletions in version 1.3. Implementing file deletion should be done. inside your own applications using the post_delete or pre_delete signal. Clearing the field if blank is true, does not delete the file. This can also be achieved using pre_save and post_save signals. This packages contains two signal callback methods that handle file deletion for all SdtImageFields of a model.:

from stdimage import pre_delete_delete_callback, pre_save_delete_callback

post_delete.connect(pre_delete_delete_callback, sender=MyModel)
pre_save.connect(pre_save_delete_callback, sender=MyModel)

Warning: You should not use the singal callbacks in production. They may result in data loss.

Re-rendering variations

You might want to add new variations to a field. That means you need to render new variations for missing fields. This can be accomplished using a management command.:

python manage.py rendervariations 'app_name.model_name.field_name' [--replace]

The replace option will replace all existing files. There is currently a memory leak, that’s why you should avoid using the replace option in cron jobs.

Testing

To run the tests simply run python setup.py test