File uploads for your users.
Almost all modern web apps allow their users to upload content such as audio, video or images. This raises a number of issues if that content should not be visible to the whole world by default.
If you add an ImageField to your user model, you need to come up with a good
idea on how to save those images. It is probably not a good idea to keep the
original filenames as they might disturb your server's file system and open
doors for hackers, who might try to brute-force against your
/media/user_profiles/
in the hope to steal some valuable files.
Since it seems inevitable to implement a function for Django's FileField's
upload_to
attribute I thought that this might be a candidate for a reusable
app.
You need at least the following packages in your virtualenv:
To get the latest stable release from PyPi::
$ pip install django-user-media
To get the latest commit from GitHub::
$ pip install -e git://github.com/bitmazk/django-user-media.git#egg=user_media
Add the app to your INSTALLED_APPS
::
INSTALLED_APPS = [
...
'user_media',
'easy_thumbnails',
'django_libs',
'generic_positions',
]
Hook the app into your main urls.py
::
urlpatterns += patterns('',
...
url(r'^umedia/', include('user_media.urls')),
)
Run the migrations to create the app's database tables::
$ ./manage.py migrate user_media
Add generic relation ++++++++++++++++++++
Let's assume that you have a UserProfile
model and you want to add an
avatar
field to that model.
First you might want to add a GenericRelation
to your UserProfile
model::
from django.contrib.contenttypes import fields
class UserProfile(models.Model):
...
user = models.ForeignKey(
getattr(settings, 'AUTH_USER_MODEL', 'auth.User'),
)
avatar = fields.GenericRelation(
'user_media.UserMediaImage',
)
Add property ++++++++++++
Now you will be able to get all uploaded images that belong to a
UserProfile
by doing this::
profile = UserProfile.objects.get(pk=1)
images = profile.avatar.all()
It makes sense to add a convenience method to your UserProfile
model::
class UserProfile(models.Model):
...
@property
def avatar(self):
try:
return self.avatar.all()[0]
except IndexError:
return None
Add link to update form +++++++++++++++++++++++
In your templates you can now provide a link to the image creation view like
this (assuming that your UserProfile
object is called object
in the
template's context)::
<a href="{% url "user_media_image_create" content_type="userprofile" object_id=object.pk %}">Upload your picture</a>
Note that userprofile
is the model name that the ContentType
of your
UserProfile
model would return. You can figure this out with ./manage.py shell
for example::
$ ./manage.py shell
In [1]: from django.contrib.contenttypes.models import ContentType
In [2]: from your_app.models import UserProfile
In [3]: ContentType.objects.get_for_model(UserProfile).model
Out [1]: u'userprofile'
When visiting that link, the user will see an image upload form. You might
want to override that template (user_media/usermediaimage_form.html
).
After uploading the image the view should redirect back to the absolute url
of your UserProfile
. If you want to redirect to another URL, you can
provide a next
URL parameter via POST or GET::
<a href="{% url "user_media_image_create" content_type="userprofile" object_id=object.pk %}?next=/foo/bar">Upload your picture</a>
Display images ++++++++++++++
Now you should have all building blocks that you need to add links or buttons
to your templates that call the views of this application. On your
UserProfile
detail view you could display the avatar, if available::
{% if object.avatar %}
<img src="{{ MEDIA_URL }}{{ object.avatar.image }}" />
{% endif %}
Delete and edit images ++++++++++++++++++++++
Or in your UserProfile
update view you could display a link to upload a
new image or to delete the existing image::
{% if form.instance.get_avatar %}
<p><img src="{{ MEDIA_URL }}{{ form.instance.avatar.image }}" /></p>
<a href="{% url "user_media_image_delete" pk=form.instance.avatar.pk %}">Delete picture</a>
{% else %}
<a href="{% url "user_media_image_create" content_type="userprofile" object_id=form.instance.pk %}">Add profile picture</a>
{% endif %}
The delete link in this example will render the
user_media/usermediaimage_confirm_delete.html
template, which you might
want to override in your project.
A link for editing an existing image would look like this::
<a href="{% url "user_media_image_edit" pk=form.instance.avatar.pk %}">Edit picture</a>
Upload from your own model form +++++++++++++++++++++++++++++++
Often you might not want to provide a dedicated form for uploading images but
you might want to have an image field right on the model form of your content
object. In this case you can inherit from UserMediaImageFormMixin
::
from django import forms
from user_media.forms import UserMediaImageFormMixin
from yourapp.models import UserProfile
class UserProfileForm(UserMediaImageFormMixin, forms.ModelForm):
image_label = _('Image')
require_user_media_image = False
image_field_name = 'user_media_image'
image_widget = forms.ClearableFileInput() # optional
# your form implementation
The mixin will dynamically add a forms.ImageField
with the name
user_media_image
to your form. You can control the label of that field by
setting the image_label
attribute on your form class. You can also make the
field mandatory by setting the require_user_media_image
attribute to True
.
You might want to call the CreateImageView
from an AJAX call, i.e. when
displaying the form in a jQuery modal. To make life easier the view will
return a different template when the request is an AJAX call.
The names of the alternative templates are
user_media/partials/ajax_usermediaimage_form.html
and
user_media/partials/ajax_usermediaimage_confirm_delete.html
.
Make sure to add a user field to the object::
user = models.ForeignKey(
getattr(settings, 'AUTH_USER_MODEL', 'auth.User'),
verbose_name=_('User'),
)
Alternatively you can add a function called user_can_edit
: ::
def user_can_edit(self, user):
"""
Function, which returns True if the user is allowed edit the instance.
"""
if user in self.users.all():
return True
return False
If you want to upload multiple images at once, only prepare the following templates::
user_media/partials/image_upload.html
user_media/partials/image.html
Then add styles and jQuery scripts. We've used blueimp's file upload, so you make it work by adding jQuery & jQuery-UI plus the scripts in::
user_media/partials/image_upload_scripts.html
Now include the form::
{% include "user_media/partials/image_upload.html" with object=request.user.get_profile maximum='5' hide_cutout='0' mode="multiple" c_type="profile" %}
You can use the variable hide_cutout="0"
to hide the link that triggers the
jQuery crop functionality.
You can limit the maximum upload by using the following setting::
USER_MEDIA_UPLOAD_MAXIMUM = 5
You can also combine single and multiple uploads. Just use the templates and add the wanted variables::
{% include "user_media/partials/image_upload.html" with object=request.user.get_profile field='logo' mode="single" show_main_thumb="True" %}
If you are using the single image upload, your newly uploaded image will
replace the current img
-element in your userMediaImageUploaded
-element.
Sometimes you might have special CSS classes on your images and you might want
to add those classes again to the img
that has just been added to the DOM. In
order to define the classes that should be added to newly loaded image, just
add the data-img-class="myclass1 myclass2"
attribute to the element that has
the userMediaImageUploaded
class.
You can easily add a frontend image cropping. First of all, add a new thumbnail
processor user_media.processors.crop_box
::
THUMBNAIL_PROCESSORS = (
'user_media.processors.crop_box',
...
'easy_thumbnails.processors.colorspace',
'easy_thumbnails.processors.autocrop',
'easy_thumbnails.processors.scale_and_crop',
'easy_thumbnails.processors.filters',
)
Then add the cropping template and the relevant js libraries::
{% include "user_media/partials/crop.html" %}
<script src="{% static "django_libs/js/getcookie.js" %}"></script>
<script src="{% static "user_media/js/libs/jquery.Jcrop.js" %}"></script>
You can modify the settings by overwriting the input fields in crop.html
.
Check out: http://deepliquid.com/content/Jcrop.html
Now, if a user clicks on Select another cutout
, the original image will be
pushed into the crop area, where the user is able to select a frame. If she
then saves the cropped area, the coordinates will be saved to the
UserMediaImage
instance.
By using the new thumbnail processor it's easy to use this coordinates to generate thumbnails::
{% thumbnail image.image image.small_size box=image.box_coordinates %}
USER_MEDIA_THUMB_SIZE_SMALL +++++++++++++++++++++++++++
Default: (95, 95)
Size of the small auto-generated thumbnails, which are processed after upload/cropping.
USER_MEDIA_THUMB_SIZE_LARGE +++++++++++++++++++++++++++
Default: (150, 150)
Size of the large auto-generated thumbnails, which are processed after upload/cropping.
USER_MEDIA_UPLOAD_MAXIMUM +++++++++++++++++++++++++
Default: 3
Amount of images to be uploaded at a maximum.
If you want to contribute to this project, please perform the following steps
.. code-block:: bash
# Fork this repository
# Clone your fork
mkvirtualenv -p python2.7 django-user-media
make develop
git co -b feature_branch master
# Implement your feature and tests
git add . && git commit
git push -u origin feature_branch
# Send us a pull request for your feature branch
In order to run the tests, simply execute tox
. This will install two new
environments (for Django 1.8 and Django 1.9) and run the tests against both
environments.