Django 1.11 - ImageFieldでheight_fieldとwidth_fieldを使用する方法

Question

異なる次元の画像を格納するために私のDjangoアプリケーションで使用されている次のモデルを定義しました。

class Image(models.Model): 

    def _img_path(instance, filename): 
     # file will be uploaded to MEDIA_ROOT/<instance.path>/<filename> 
     return '{0}/{1}'.format(instance.path, filename) 

    id = models.AutoField(primary_key=True) 
    path = models.CharField(max_length=500) 
    img = models.ImageField(upload_to=_img_path, max_length=500, height_field='img_height', width_field='img_width') 
    img_md = models.ImageField(upload_to=_img_path, max_length=500, height_field='img_height', width_field='img_width', null=True) 
    img_sm = models.ImageField(upload_to=_img_path, max_length=500, height_field='img_height', width_field='img_width', null=True) 
    img_xs = models.ImageField(upload_to=_img_path, max_length=500, height_field='img_height', width_field='img_width', null=True) 

私は次のように画像を保存しシリアライザのコードで、APIのDjangoのRESTフレームワークを使用していますので：私はなぜ知らないが、私は取得しています

class ProductDrawingSerializer(ModelSerializer): 
    drawing = ImageSerializer() 

    class Meta: 
     model = ProductDrawing 
     fields = [ 
      'product', 
      'drawing', 
     ] 

    def create(self, validated_data): 
     product = validated_data['product'] 
     filename = 'product-{0}.{1}'.format(product.pk, 'jpg') 
     filename_xs = 'product-{0}_{1}.{2}'.format(product.pk, 'xs', 'jpg') 
     # resize_image() is just function I wrote that uses the Pillow Image.resize() 
     resize_image(validated_data['drawing']['img'], 'temp_files/'+filename, max_w=1500.0, max_h=1500.0, max_file_size=0.7, to_jpeg=True) 
     resize_image(validated_data['drawing']['img'], 'temp_files/'+filename_xs, max_w=120.0, max_h=120.0, max_file_size=0.01, max_img_quality=98, to_jpeg=True, do_trim=True) 
     drawing = Image() 
     drawing.path = 'drawings' 
     drawing.img.save(filename, File(open('temp_files/'+filename, 'rb')), save=False) 
     drawing.img_xs.save(filename_xs, File(open('temp_files/'+filename_xs, 'rb')), save=False) 
     drawing.save() 

     product_drawing = ProductDrawing(product=product,drawing=drawing) 
     product_drawing.save() 
     return product_drawing 

AttributeError：

'Image' object has no attribute 'img_width' 

トレースバック：

Environment: 


Request Method: POST 
Request URL: http://127.0.0.1:8000/api/products/1/drawings/add/ 

Django Version: 1.11.2 
Python Version: 3.6.1 
Installed Applications: 
['django.contrib.admin', 
'django.contrib.auth', 
'django.contrib.contenttypes', 
'django.contrib.sessions', 
'django.contrib.messages', 
'django.contrib.staticfiles', 
'rest_framework', 
'product', 
'brand'] 
Installed Middleware: 
['django.middleware.security.SecurityMiddleware', 
'django.contrib.sessions.middleware.SessionMiddleware', 
'django.middleware.common.CommonMiddleware', 
'django.middleware.csrf.CsrfViewMiddleware', 
'django.contrib.auth.middleware.AuthenticationMiddleware', 
'django.contrib.messages.middleware.MessageMiddleware', 
'django.middleware.clickjacking.XFrameOptionsMiddleware'] 



Traceback: 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner 
    41.    response = get_response(request) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response 
    187.     response = self.process_exception_by_middleware(e, request) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response 
    185.     response = wrapped_callback(request, *callback_args, **callback_kwargs) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/views/decorators/csrf.py" in wrapped_view 
    58.   return view_func(*args, **kwargs) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/views/generic/base.py" in view 
    68.    return self.dispatch(request, *args, **kwargs) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/views.py" in dispatch 
    489.    response = self.handle_exception(exc) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/views.py" in handle_exception 
    449.    self.raise_uncaught_exception(exc) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/views.py" in dispatch 
    486.    response = handler(request, *args, **kwargs) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/generics.py" in post 
    192.   return self.create(request, *args, **kwargs) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/mixins.py" in create 
    21.   self.perform_create(serializer) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/mixins.py" in perform_create 
    26.   serializer.save() 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/rest_framework/serializers.py" in save 
    215.    self.instance = self.create(validated_data) 

File "~/Documents/Django projects/myapp/product/api/serializers.py" in create 
    202.   drawing.img.save(filename, File(open('temp_files/'+filename, 'rb')), save=False) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/db/models/fields/files.py" in save 
    95.   setattr(self.instance, self.field.name, self.name) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/db/models/fields/files.py" in __set__ 
    377.    self.field.update_dimension_fields(instance, force=True) 

File "/anaconda/envs/myapp-env/lib/python3.6/site-packages/django/db/models/fields/files.py" in update_dimension_fields 
    464.    (self.width_field and not getattr(instance, self.width_field)) or 

Exception Type: AttributeError at /api/products/1/drawings/add/ 
Exception Value: 'ImageModel' object has no attribute 'img_width' 

属性height_fieldとwidth_fieldが自動的にポピュレートされていると考えました。 それらを正しく使用するにはどうすればよいですか？あなたは、パラメータの名前と等しい値を持つモデル に列を追加する必要がある

Answer 1

：のheight_fieldは、あなたがここにfield-attributeを読んで、ソースImageField