Package: django-athumb
django-athumbAuthor:Greg TaylorLicense:BSDStoring images and their thumbnails on S3 is a bit of a clumbsy endeavor with
Django. While this Django app may work with more typical storage backends, it
is intended to accept image uploads, thumbnail them, and upload the original
plus the thumbs to S3. You may then get to the thumbnails in your template
by doing something like:<img src="{% thumbnail some_obj.image '80x80' %}" />This automatically assembles the remote S3 URL to retrieve the thumbnail from.
No error checking is done, and several assumptions are made for the sake of
speed.Advantages of django-athumbThe primary advantage of django-athumb is that, unlike sorl and others,
thumbnails are generated at the time of user uploading the original image.
Instead of generating thumbs on-demand, or needing a caching layer, we generate
pre-defined thumbnails at time of upload. This leads to a few big benefits:We never check for the existence of a file, after the first save/upload. We
assume it exists, skipping the need to hit caches or the disk. This makes
us faster and more simple than some of the other alternatives.Since we define every possible thumbnail in advance via models.py, we have
a defined set of possible values. Thumbnails sizes can also be named anything,
whether it be ‘60x60_cropped’ or ‘medium_nocrop’.Disadvantages of django-athumbThis wouldn’t be a fair assessment without some of these:Some may prefer to define thumbnail sizes in templates. This is largely
preference.We only support simple scaling/cropping/centering as thumbnail operations.
sorl and others are going to give you a whole lot more gadgets out of the box.LicenseAll code is under a BSD-style license, see LICENSE for details.Source:http://github.com/duointeractive/django-athumbRequirementspython >= 2.7django >= 1.6boto >= 3.0Pillow >= 2.5.0InstallationTo install run:pip install django-athumbor:easy_install django-athumbConfigurationsettings.pyAdd toINSTALLED_APPS:'athumb'Add toTEMPLATE_CONTEXT_PROCESSORSinsettings.py:'django.core.context_processors.request'If you want S3 storage as your default file back-end:# If you don't want this to be the global default, just make sure you
# specify the S3BotoStorage_AllPublic backend on a per-field basis.
DEFAULT_FILE_STORAGE = 'athumb.backends.s3boto.S3BotoStorage_AllPublic'Then setup some values used by the backend:AWS_ACCESS_KEY_ID = 'YourS3AccessKeyHere'
AWS_SECRET_ACCESS_KEY = 'YourS3SecretAccessKeyHere'
AWS_STORAGE_BUCKET_NAME = 'OneOfYourBuckets'If you would like to use a vanity domain instead of s3.amazonaws.com, you
first should configure it in amazon and then add this to settings:AWS_STORAGE_BUCKET_CNAME = 'static.yourdomain.com'If you want a cache buster for your thumbnails (a string added to the end of
the image URL that causes browsers to re-fetch the image after changes), you
can set a value like this:MEDIA_CACHE_BUSTER = 'SomeValue'You do not need to specify a cache buster.If you aren’t using the default S3 region, you can define it with the following
setting:AWS_REGION = 'us-east-1'Using in modelsAfter you have all of the above configured, you’re ready to start using
athumb in your models. Here is an example model with a thumbnailing field.from django.db import models
from athumb.fields import ImageWithThumbsField
from athumb.backends.s3boto import S3BotoStorage_AllPublic

# It is generally good to keep these stored in their own module, to allow
# for other models.py modules to import the values. This assumes that more
# than one model stores stuff in the same bucket.
PUBLIC_MEDIA_BUCKET = S3BotoStorage_AllPublic(bucket='public-media')

class YourModel(models.Model)
    image = ImageWithThumbsField(
        upload_to="store/product_images",
        thumbs=(
            ('50x50_cropped', {'size': (50, 50), 'crop': True}),
            ('60x60', {'size': (60, 60)}),
            ('80x1000', {'size': (80, 1000)}),
            ('front_page', {'size': (120, 1000)}),
            ('medium', {'size': (161, 1000)}),
            ('large', {'size': (200, 1000)}),
        ),
        blank=True, null=True,
        storage=PUBLIC_MEDIA_BUCKET)A few things to note:The tuples inthumbsare in the format of(name, options). The value
fornamecan be whatever string you’d like. Notice that you can make the
names dimensions, or something entirely different.Thestoragekeyword is important, used for specifying the bucket for the
field. If you don’t specifystorage, the default backend is used. As a
shortcut, you could setS3BotoStorage_AllPublicas your default backend,
and theAWS_*values would determine the default bucket.Backendsdjango-athumb comes with a simplified s3boto backend, modified from those found
in the django-storages project. For most cases, you’ll want to useathumb.backends.s3boto.S3BotoStorage_AllPublic, as it does not use HTTPS, and
is a good bit faster thanS3BotoStoragebecause it makes some assumptions.NoteThis module is primarily aimed at storing and serving images to/from
S3. I have not tested it at all with the standard Django Filesystem backend,
though itshouldwork.Template TagsWhen referring to media in HTML templates you can use custom template tags.
These tags can by accessed by loading the athumb template tag collection.{% load thumbnail %}If you’d like to make the athumb tags global, you can add the following to
your master urls.py file:from django.template import add_to_builtins
add_to_builtins(‘athumb.templatetags.thumbnail’)Some backends (S3) support https URLs when the requesting page is secure.
In order for the https to be detected, the request must be placed in the
template context with the key'request'. This can be done automatically by adding'django.core.context_processors.request'toTEMPLATE_CONTEXT_PROCESSORSin settings.pythumbnailReturns the URL for the specified thumbnail size (as per the object’s
models.py Model class):{% thumbnail some_obj.image '50x50_cropped' %}or, to save the value in a template context variable:{% thumbnail some_obj.image 'front_page' as 'some_var' %}As long as you’ve got Django’s request context processor in, the thumbnail tag
will detect when the current view is being served over SSL, and automatically
convert any http to https in the thumbnail URL. If you want to always force
SSL for a thumbnail, add it as an argument like this:{% thumbnail some_obj.image '60x60' force_ssl=True %}To put the thumbnail URL on the context instead of just rendering
it, finish the tag withas [context_var_name]:{% thumbnail image '60x60' as 'thumb' %}
<img src="{{ thumb }}" />manage.py commandsathumb_regen_field# ./manage.py athumb_regen_field <app.model> <field>Re-generates thumbnails for all instances of the given model, for the given
field.To-DoSee the issue tracker for a list of outstanding things needing doing.Change Log2.4.1Fixes to restore compatibility with migrations. (jneves)2.4Changes to add Django 1.7 compatibility.2.3Embed pial, eliminating the need to install it separately.2.2Added support for different S3 regions via the AWS_REGION setting.Improved error handling.2.1Make MEDIA_CACHE_BUSTER optional.Documented MEDIA_CACHE_BUSTER.2.0Complete re-work of the way thumbnails are specified in models.py.Removal of the attribute-based image field size retrieval, since we no
longer are just limited to dimensions.Further misc. improvements.1.0Initial release.