old_contents: from django.contrib import admin
  
  from bulk_admin import BulkModelAdmin
  from mptt.admin import MPTTModelAdmin
  
  from .models import Post, Category, Media, Link
  
  # Register your models here.
  
  @admin.register(Post)
  class PostAdmin(admin.ModelAdmin):
      prepopulated_fields = { 'slug': ['title'] }
      search_fields = ['title']
      list_display = ('title', 'get_full_url', 'pub_date', 'admin_first_image', )
      
      # add a link to the blog post on the admin list display to make it easier to preview the post
      def get_full_url(self, instance):
          return "<a href='%s'>%s</a>" % (instance.get_absolute_url(), instance.get_absolute_url())
      get_full_url.short_description = 'Link'
      get_full_url.allow_tags = True
      
      # show the first image on the admin list so we can make sure it gets set
      def admin_first_image(self, instance):
          if not instance.first_image:
              return u'None'
          return u'<img src="%s" height="150" />' % (instance.first_image.url)
          
      admin_first_image.short_description = 'First Image'
      admin_first_image.allow_tags = True
  
  
  @admin.register(Category)
  class CategoryAdmin(MPTTModelAdmin):
      prepopulated_fields = { 'slug': ['title'] }
  
  
  @admin.register(Media)
  class MediaAdmin(BulkModelAdmin):
      search_fields = ['image_name']
      list_display = ('image_name', 'pub_date', 'admin_thumbnail', 'admin_full', )
      
      # this stuff is to show a preview of the image in the admin list
      def admin_thumbnail(self, instance):
          if not instance.scale_image:
              return u'None'
          return u'<img src="%s" height="150" />' % (instance.scale_image.url)
          
      admin_thumbnail.short_description = 'Image'
      admin_thumbnail.allow_tags = True
      
      def admin_full(self, instance):
          return u'<img src="%s" height="150" />' % (instance.full_image.url)
          
      admin_full.short_description = 'Full Image'
      admin_full.allow_tags = True
      
      
  @admin.register(Link)
  class LinkAdmin(admin.ModelAdmin):
      pass
new_contents: from django.contrib import admin
  
  from bulk_admin import BulkModelAdmin
  from mptt.admin import MPTTModelAdmin
  
  from .models import Post, Category, Media, Link
  
  # Register your models here.
  
  @admin.register(Post)
  class PostAdmin(admin.ModelAdmin):
      prepopulated_fields = { 'slug': ['title'] }
      search_fields = ['title']
      list_display = ('title', 'get_full_url', 'pub_date', 'admin_first_image', )
      
      # add a link to the blog post on the admin list display to make it easier to preview the post
      def get_full_url(self, instance):
          return "<a href='%s'>%s</a>" % (instance.get_absolute_url(), instance.get_absolute_url())
      get_full_url.short_description = 'Link'
      get_full_url.allow_tags = True
      
      # show the first image on the admin list so we can make sure it gets set
      def admin_first_image(self, instance):
          if not instance.first_image:
              return u'None'
          return u'<img src="%s" height="150" width="300" />' % (instance.first_image.url)
          
      admin_first_image.short_description = 'First Image'
      admin_first_image.allow_tags = True
  
  
  @admin.register(Category)
  class CategoryAdmin(MPTTModelAdmin):
      prepopulated_fields = { 'slug': ['title'] }
  
  
  @admin.register(Media)
  class MediaAdmin(BulkModelAdmin):
      search_fields = ['image_name']
      list_display = ('image_name', 'pub_date', 'admin_thumbnail', 'admin_full', )
      
      # this stuff is to show a preview of the image in the admin list
      def admin_thumbnail(self, instance):
          if not instance.scale_image:
              return u'None'
          return u'<img src="%s" height="150" width="300" />' % (instance.scale_image.url)
          
      admin_thumbnail.short_description = 'Image'
      admin_thumbnail.allow_tags = True
      
      def admin_full(self, instance):
          return u'<img src="%s" height="150" width="300" />' % (instance.full_image.url)
          
      admin_full.short_description = 'Full Image'
      admin_full.allow_tags = True
      
      
  @admin.register(Link)
  class LinkAdmin(admin.ModelAdmin):
      pass
subject: add a width constraint to the admin image previews