Refactored the thumbnail from imagefield to filefield.

Why? ImageField causes hits to storage to fill out certain fields. Added a storage class and width/height fields so it is possible to scale the thumbnails and store them somewhere besides the filesystem.

categories/migrations/0004_auto__add_field_category_thumbnail_width__add_field_category_thumbnail.py

@@ -0,0 +1,55 @@
+# encoding: utf-8
+import datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        
+        # Adding field 'Category.thumbnail_width'
+        db.add_column('categories_category', 'thumbnail_width', self.gf('django.db.models.fields.IntegerField')(null=True, blank=True), keep_default=False)
+
+        # Adding field 'Category.thumbnail_height'
+        db.add_column('categories_category', 'thumbnail_height', self.gf('django.db.models.fields.IntegerField')(null=True, blank=True), keep_default=False)
+
+        # Changing field 'Category.thumbnail'
+        db.alter_column('categories_category', 'thumbnail', self.gf('django.db.models.fields.files.FileField')(max_length=100, null=True))
+
+
+    def backwards(self, orm):
+        
+        # Deleting field 'Category.thumbnail_width'
+        db.delete_column('categories_category', 'thumbnail_width')
+
+        # Deleting field 'Category.thumbnail_height'
+        db.delete_column('categories_category', 'thumbnail_height')
+
+        # Changing field 'Category.thumbnail'
+        db.alter_column('categories_category', 'thumbnail', self.gf('django.db.models.fields.files.ImageField')(max_length=100, null=True))
+
+
+    models = {
+        'categories.category': {
+            'Meta': {'ordering': "('tree_id', 'lft')", 'unique_together': "(('parent', 'name'),)", 'object_name': 'Category'},
+            'alternate_title': ('django.db.models.fields.CharField', [], {'default': "''", 'max_length': '100', 'blank': 'True'}),
+            'description': ('django.db.models.fields.TextField', [], {'null': 'True', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'level': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
+            'lft': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
+            'meta_extra': ('django.db.models.fields.TextField', [], {'default': "''", 'blank': 'True'}),
+            'meta_keywords': ('django.db.models.fields.CharField', [], {'default': "''", 'max_length': '255', 'blank': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'order': ('django.db.models.fields.IntegerField', [], {'null': 'True', 'blank': 'True'}),
+            'parent': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'children'", 'null': 'True', 'to': "orm['categories.Category']"}),
+            'rght': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'}),
+            'slug': ('django.db.models.fields.SlugField', [], {'max_length': '50', 'db_index': 'True'}),
+            'thumbnail': ('django.db.models.fields.files.FileField', [], {'max_length': '100', 'null': 'True', 'blank': 'True'}),
+            'thumbnail_height': ('django.db.models.fields.IntegerField', [], {'null': 'True', 'blank': 'True'}),
+            'thumbnail_width': ('django.db.models.fields.IntegerField', [], {'null': 'True', 'blank': 'True'}),
+            'tree_id': ('django.db.models.fields.PositiveIntegerField', [], {'db_index': 'True'})
+        }
+    }
+
+    complete_apps = ['categories']

categories/models.py

@@ -5,11 +5,16 @@ from django.db import models
 from django.utils.encoding import force_unicode
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
+from django.core.files.storage import get_storage_class
+from django.template.defaultfilters import slugify
 from django.utils.translation import ugettext as _
 
 from mptt.models import MPTTModel
 
-from settings import RELATION_MODELS, RELATIONS, THUMBNAIL_UPLOAD_PATH
+from settings import (RELATION_MODELS, RELATIONS, THUMBNAIL_UPLOAD_PATH, 
+                        THUMBNAIL_STORAGE)
+
+STORAGE = get_storage_class(THUMBNAIL_STORAGE)
 
 class Category(MPTTModel):
     parent = models.ForeignKey('self', 
@@ -19,7 +24,12 @@ class Category(MPTTModel):
         help_text="Leave this blank for an Category Tree", 
         verbose_name='Parent')
     name = models.CharField(max_length=100)
-    thumbnail = models.ImageField(upload_to=THUMBNAIL_UPLOAD_PATH, null=True, blank=True)
+    thumbnail = models.FileField(
+        upload_to=THUMBNAIL_UPLOAD_PATH, 
+        null=True, blank=True,
+        storage=STORAGE(),)
+    thumbnail_width = models.IntegerField(blank=True, null=True)
+    thumbnail_height = models.IntegerField(blank=True, null=True)
     order = models.IntegerField(blank=True, null=True)
     slug = models.SlugField()
     alternate_title = models.CharField(
@@ -63,6 +73,20 @@ class Category(MPTTModel):
             """
             return self.storyrelation_set.filter(relation_type=relation_type)
     
+    def save(self, *args, **kwargs):
+        if not self.slug:
+            self.slug = slugify(self.name)[:50]
+        if self.thumbnail:
+            from django.core.files.images import get_image_dimensions
+            width, height = get_image_dimensions(self.thumbnail.file, close=True)
+        else:
+            width, height = None, None
+        
+        self.thumbnail_width = width
+        self.thumbnail_height = height
+        
+        super(Category, self).save(*args, **kwargs)
+    
     class Meta:
         verbose_name_plural = 'categories'
         unique_together = ('parent', 'name')

categories/settings.py

@@ -10,6 +10,7 @@ DEFAULT_SETTINGS = {
     'M2M_REGISTRY': [],
     'FK_REGISTRY': [],
     'THUMBNAIL_UPLOAD_PATH': 'uploads/categories/thumbnails',
+    'THUMBNAIL_STORAGE': settings.DEFAULT_FILE_STORAGE,
 }
 
 DEFAULT_SETTINGS.update(getattr(settings, 'CATEGORIES_SETTINGS', {}))