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Firstly, create a widgets.py
file in an app. For my example, I’ll be making you an AdminImageWidget
class that extends AdminFileWidget
. Essentially, I want a image upload field that shows the currently uploaded image in an <img src="" />
tag instead of just outputting the file’s path.
Put the following class in your widgets.py
file:
from django.contrib.admin.widgets import AdminFileWidget
from django.utils.translation import ugettext as _
from django.utils.safestring import mark_safe
import os
import Image
class AdminImageWidget(AdminFileWidget):
def render(self, name, value, attrs=None):
output = []
if value and getattr(value, "url", None):
image_url = value.url
file_name=str(value)
# defining the size
size='100x100'
x, y = [int(x) for x in size.split('x')]
try :
# defining the filename and the miniature filename
filehead, filetail = os.path.split(value.path)
basename, format = os.path.splitext(filetail)
miniature = basename + '_' + size + format
filename = value.path
miniature_filename = os.path.join(filehead, miniature)
filehead, filetail = os.path.split(value.url)
miniature_url = filehead + '/' + miniature
# make sure that the thumbnail is a version of the current original sized image
if os.path.exists(miniature_filename) and os.path.getmtime(filename) > os.path.getmtime(miniature_filename):
os.unlink(miniature_filename)
# if the image wasn't already resized, resize it
if not os.path.exists(miniature_filename):
image = Image.open(filename)
image.thumbnail([x, y], Image.ANTIALIAS)
try:
image.save(miniature_filename, image.format, quality=100, optimize=1)
except:
image.save(miniature_filename, image.format, quality=100)
output.append(u' <div><a href="%s" target="_blank"><img src="%s" alt="%s" /></a></div> %s ' % \
(miniature_url, miniature_url, miniature_filename, _('Change:')))
except:
pass
output.append(super(AdminFileWidget, self).render(name, value, attrs))
return mark_safe(u''.join(output))
Ok, so what’s happening here?
- I import an existing widget (you may be starting from scratch, but should probably be able to extend ClearableFileInput if that’s what you are starting with)
- I only want to change the output/presentation of the widget, not the underlying logic. So, I override the widget’s
render
function. - in the render function I build the output I want as an array
output = []
you don’t have to do this, but it saves some concatenation. 3 key lines:output.append(u' <div><a href="%s" target="_blank"><img src="%s" alt="%s" /></a></div> %s ' % (miniature_url, miniature_url, miniature_filename, _('Change:')))
Adds an img tag to the outputoutput.append(super(AdminFileWidget, self).render(name, value, attrs))
adds the parent’s output to my widgetreturn mark_safe(u''.join(output))
joins my output array with empty strings AND exempts it from escaping before display
How do I use this?
class SomeModelForm(forms.ModelForm):
"""Author Form"""
photo = forms.ImageField(
widget = AdminImageWidget()
)
class Meta:
model = SomeModel
OR
class SomeModelForm(forms.ModelForm):
"""Author Form"""
class Meta:
model = SomeModel
widgets = {'photo' : AdminImageWidget(),}
Which gives us:
Source:stackexchange.com