Manipulate file directly

Author: hirunatan

testing/settings.py

@@ -1,5 +1,7 @@
 import os
 
+PROJECT_ROOT = os.path.dirname(os.path.realpath(__file__))
+
 DEBUG = True
 
 AUTHNET_LOGIN_ID = ''
@@ -48,3 +50,7 @@
 
 USE_I18N = True
 
+MEDIA_ROOT = os.path.join(PROJECT_ROOT, 'media')
+
+MEDIA_URL = '/media/'
+

validatedfile/models.py

@@ -1,5 +1,23 @@
-from django.db import models
+from django.db.models import FileField
 
-class ValidatedFileField(models.FileField):
-    pass
+class ValidatedFileField(FileField):
+    def __init__(self, *args, **kwargs):
+        self.content_types = kwargs.pop("content_types")
+        self.max_upload_size = kwargs.pop("max_upload_size")
+        super(ValidatedFileField, self).__init__(*args, **kwargs)
 
+    def clean(self, *args, **kwargs):        
+        data = super(ValidatedFileField, self).clean(*args, **kwargs)
+
+        file = data.file
+        try:
+            content_type = file.content_type
+            if content_type in self.content_types:
+                if file._size > self.max_upload_size:
+                    raise forms.ValidationError(_('Please keep filesize under %s. Current filesize %s') % (filesizeformat(self.max_upload_size), filesizeformat(file._size)))
+            else:
+                raise forms.ValidationError(_('Filetype not supported.'))
+        except AttributeError:
+            pass        
+
+        return data

validatedfile/tests/__init__.py

@@ -1,10 +1,22 @@
 from django.test import TestCase
+from django.core.files import File
 
 from models import TestModel
 
 class ValidatedFileFieldTest(TestCase):
 
-    def test_create_instance(self):
-        instance = TestModel()
+    def test_create_empty_instance(self):
+        instance = TestModel.objects.create()
         instance.save()
 
+    def test_create_instance_with_file(self):
+        instance = TestModel.objects.create(
+                the_file = File(open('validatedfile/tests/image2k.png'), 'the_file.png')
+            )
+        instance.save()
+
+        self.assertEqual(instance.the_file.url, '/media/testfile/the_file.png')
+
+        instance.the_file.delete()
+        instance.delete()
+

validatedfile/tests/image2k.png

@@ -3,5 +3,10 @@
 from ..models import *
 
 class TestModel(models.Model):
-    the_file = ValidatedFileField(upload_to = 'testfile')
+    the_file = ValidatedFileField(
+                    null = True,
+                    blank = True,
+                    upload_to = 'testfile',
+                    content_types = 'image/png',
+                    max_upload_size = 10240)