README.md

django-dragndrop-related

Add drag-and-drop multiple uploading to any Django model where a related model is used to store images or files, using the awesome Dropzone.js.

The example project shown uses django-admin-thumbnails to show ImageField preview thumbnails.

Rationale

One of the most common requests I get from clients when working on Django projects is to support some kind of drag-and-drop upload to save them the tedium of working with multiple file upload fields. I finally put some effort into solving this problem and came up with this library, which essentially provides for the creation of related models via AJAX POST request.

It assumes some simplicity on the part of the related model – e.g. that a valid instance only requires a single ImageField or FileField to be populated – and uses Dropzone.js to accept uploads and fire off POST requests to an endpoint which creates new child models using the related manager of the parent model.

I decided not to try to support drag-and-drop uploads when creating parent model instances, since the uploads would need to be stashed somewhere temporarily then associated with the new model when it was saved. Instead this library operates only on existing model instances and requires the user to reload the page once they're done dropping files, so that Django's admin/inline UI can display the newly created child models for editing. This is acceptable in my use-cases but may not be in yours.

Compatibility

This library has been tested on Django 3.2 and 4.0 on Python 3.8, though I expect it to be fairly compatible with other versions. For now, the package is marked as requiring Python 3.6 or higher.

Please note that this library is an early beta release, mostly published so that I can share code between my own projects. It works well for my specific use-case but your mileage may vary. If you have issues with the library please open a ticket and I'll review it, but be aware it's not being developed intensively at this stage.

Installation

$ pip install django-dragndrop-related

Usage

Add dragndrop_related to your INSTALLED_APPS setting:

INSTALLED_APPS = [
    # ...
    'dragndrop_related',
]

Import the mixin and apply it to your "parent" class's ModelAdmin:

from django.contrib import admin
from dragndrop_related.views import DragAndDropRelatedImageMixin

from .models import Album, Image


''' Assuming a 'parent' model of Album and a 'child' model of Image, related
    to Album by a `ForeignKey` field (see examples below)
'''


class ImageInline(admin.StackedInline):
    extra = 0
    model = Image


@admin.register(Album)
class AlbumAdmin(DragAndDropRelatedImageMixin, admin.ModelAdmin):
    inlines = [ImageInline]

Usage in combination with django-solo

The django-solo library provides its own admin change_form template with some minimal UI changes to assist with singleton models. When using django-dragndrop-related with a django-solo singleton model, there is a different mixin which will preserve the proper template inheritance:

from dragndrop_related.views import DragAndDropSingletonRelatedImageMixin
from solo.admin import SingletonModelAdmin

@admin.register(models.Homepage)
class HomepageAdmin(DragAndDropSingletonRelatedImageMixin, SingletonModelAdmin):
    # ...

Configuration

The library makes a few assumptions about your models and their relationship. Consider the following example models:

class Album(models.Model):
    # ...


class Image(models.Model):
    # ...

    album = models.ForeignKey(
        'gallery.Album',
        related_name='images'
    )

    image = models.ImageField()

1. When adding related child instances to a parent model instance, the library will attempt to use a related manager called images. This can be overridden by specifying the related_manager_field_name property on the class that inherits from DragAndDropRelatedImageMixin, e.g.

class Image(models.Model):
    # ...

    album = models.ForeignKey(
        'gallery.Album',
        related_name='album_images'
    )

class AlbumAdmin(DragAndDropRelatedImageMixin, admin.ModelAdmin):
    # ...

    related_manager_field_name = 'album_images'

2. The library assumes the field on the related child model where the uploaded images/files should be saved is called image. This can be overridden by specifying the related_model_field_name property on the class that inherits from DragAndDropRelatedImageMixin, e.g.

class Image(models.Model):
    # ...

    album = models.ForeignKey(
        'gallery.Album',
        related_name='images'
    )

    my_image = models.ImageField()

class AlbumAdmin(DragAndDropRelatedImageMixin, admin.ModelAdmin):
    # ...

    related_model_field_name = 'my_image'

3. If you use an ordering field on your related child model, e.g. to implement django-admin-sortable2, you can specify it in your ModelAdmin using the related_model_order_field_name property and django-dragndrop-related will set a useful value for the field when creating new related model instances. E.g.

class Image(models.Model):
    # ...

    order = models.PositiveIntegerField()

    class Meta:
        ordering = ['order']

class AlbumAdmin(DragAndDropRelatedImageMixin, admin.ModelAdmin):
    # ...

    related_model_order_field_name = 'order'

4. The Dropzone.js library supports an acceptFiles configuration option which restricts the types of files that can be selected or dropped in. If the field on your related child model is an ImageField, an acceptFiles value of image/* will be passed to Dropzone.js. For a FileField no restriction is specified by default. You can override the value of acceptFiles passed to Dropzone.js by specifying the dropzone_accepted_files property on the class that inherits from DragAndDropRelatedImageMixin, e.g.

class AlbumAdmin(DragAndDropRelatedImageMixin, admin.ModelAdmin):
    # ...

    dropzone_accepted_files = 'application/pdf'

See Mozilla's documentation for the file input type for more information about how these types can be specified.

Development

If working locally on the package you can install the development tools via pip:

$ pip install -e .[dev]

Run the bundled Django example project:

$ cd example_project
$ python manage.py migrate
$ python manage.py createsuperuser
$ python manage.py runserver 0.0.0.0:8000
$ open http://localhost:8000/admin/

Navigate to the example Album model in the Gallery app to see the widget in action.

To lint with flake8:

$ flake8

Issues, Suggestions, Contributions

...are welcome on GitHub. Thanks for your interest in django-dragndrop-related!