Source code for vstutils.models.fields

# cython: binding=True
import orjson
from django.core.files.uploadedfile import SimpleUploadedFile
from django.core.files.images import ImageFile
from django.db.models import TextField, ForeignKey, FileField, ImageField, Field
from django.db.models.fields.files import FileDescriptor, FieldFile
from django.db.models.query_utils import DeferredAttribute
from vstutils.utils import raise_context_decorator_with_default

These model fields used in :class:`vstutils.api.serializers.VstSerializer`
to form model_field_class: serializer_field_class mapping

[docs]class MultipleFieldFile(FieldFile): """ Subclasses :class:`django.db.models.fields.files.FieldFile`. Provides :meth:`` and :meth:`MultipleFieldFile.delete` to manipulate the underlying file, as well as update the associated model instance. """ def __init__(self, instance, field, name): super(MultipleFieldFile, self).__init__(instance, field, name) self._old_name = def _set_attr_value(self): """ Set new value of file to object attr. """ setattr( self.instance, self.field.attname, [ if == self._old_name else file for file in getattr(self.instance, self.field.attname) ] ) def _clear_attr_value(self): """ Pop None values from file list. """ setattr( self.instance, self.field.attname, [ file for file in getattr(self.instance, self.field.attname) if != ] )
[docs] def save(self, name, content, save=True): """ Save changes in file to storage and to object attr. """ self._old_name = name = self.field.generate_filename(self.instance, name) =, content, max_length=self.field.max_length) self._set_attr_value() self._committed = True if save:
[docs] def delete(self, save=True): """ Delete file from storage and from object attr. """ if not self: return # nocv if hasattr(self, '_file'): self.close() del self.file self._clear_attr_value() self._committed = False if save:
[docs]class MultipleFileDescriptor(FileDescriptor): """ Subclasses :class:`django.db.models.fields.files.FileDescriptor` to handle list of files. Return a list of :class:`MultipleFieldFile` when accessed so you can write code like: .. sourcecode:: python from myapp.models import MyModel instance = MyModel.objects.get(pk=1) instance.files[0].size """
[docs] def get_file(self, file, instance): """ Always return valid attr_class object. For details on logic see :meth:`django.db.models.fields.files.FileDescriptor.__get__`. """ if isinstance(file, str) or file is None: attr = self.field.attr_class(instance, self.field, file) file = attr elif isinstance(file, SimpleUploadedFile): file_copy = self.field.attr_class(instance, self.field, file_copy.file = file file_copy._committed = False # pylint: disable=W0212 protected-access file = file_copy elif isinstance(file, MultipleFieldFile) and instance != file.instance: # nocv file.instance = instance file.field = self.field = return file
def __get__(self, instance, cls=None): """ Return list of MultipleFieldFile at all times. """ if instance is None: return self # nocv instance.__dict__[self.field.attname] = [ self.get_file(file, instance) for file in DeferredAttribute.__get__(self, instance, cls) or [] ] return instance.__dict__[self.field.attname]
[docs]class MultipleFileMixin: """ Mixin suited to use with :class:`django.db.models.fields.files.FieldFile` to transform it to a Field with list of files. """ def __init__(self, **kwargs): kwargs['max_length'] = None super().__init__(**kwargs)
[docs] def pre_save(self, model_instance, add): """ Call .save() method on every file in list """ files = getattr(model_instance, self.attname) for file in files: if file and not file._committed: # pylint: disable=W0212 protected-access, file.file, save=False) return files
[docs] def get_prep_value(self, value): """ Prepare value for database insertion """ value = Field.get_prep_value(self, value) if value is None: return value return orjson.dumps(list(map(str, value))).decode('utf-8')
@raise_context_decorator_with_default(default=[]) def from_db_value(self, value, expression, connection): """ Transform db value to an internal value """ if value: return orjson.loads(value) return value # nocv def get_internal_type(self): return "TextField"
[docs]class MultipleFileField(MultipleFileMixin, FileField): """ Subclasses :class:`django.db.models.fields.files.FileField`. Field for storing a list of Storage-kept files. All args passed to FileField. """ attr_class = MultipleFieldFile descriptor_class = MultipleFileDescriptor description = "List of Files"
[docs]class MultipleImageFieldFile(ImageFile, MultipleFieldFile): """ Subclasses :class:`MultipleFieldFile` and :class:`ImageFile mixin`, handles deleting _dimensions_cache when file is deleted. """ def delete(self, save=True): if hasattr(self, '_dimensions_cache'): del self._dimensions_cache super().delete(save)
[docs]class MultipleImageField(MultipleFileMixin, ImageField): """ Field for storing a list of storage-kept images. All args are passed to :class:`django.db.models.fields.files.ImageField`, except height_field and width_field, they are not currently implemented. """ attr_class = MultipleImageFieldFile descriptor_class = MultipleFileDescriptor description = "List of Images" def update_dimension_fields(self, instance, force=False, *args, **kwargs): pass
[docs]class NamedBinaryFileInJSONField(TextField): """ Extends :class:`django.db.models.TextField`. Use this field in :class:`vstutils.models.BModel` to get `vstutils.api.NamedBinaryFileInJSONField` in serializer. """
[docs]class NamedBinaryImageInJSONField(NamedBinaryFileInJSONField): """ Extends :class:`django.db.models.TextField`. Use this field in :class:`vstutils.models.BModel` to get `vstutils.api.NamedBinaryImageInJSONField` in serializer. """
[docs]class MultipleNamedBinaryFileInJSONField(TextField): """ Extends :class:`django.db.models.TextField`. Use this field in :class:`vstutils.models.BModel` to get `vstutils.api.MultipleNamedBinaryFileInJSONField` in serializer. """
[docs]class MultipleNamedBinaryImageInJSONField(MultipleNamedBinaryFileInJSONField): """ Extends :class:`django.db.models.TextField`. Use this field in :class:`vstutils.models.BModel` to get `vstutils.api.MultipleNamedBinaryImageInJSONField` in serializer. """
[docs]class FkModelField(ForeignKey): """ Extends :class:`django.db.models.ForeignKey`. Use this field in :class:`vstutils.models.BModel` to get `vstutils.api.FkModelField` in serializer. To set Foreign Key relation set `to` argument to string path to model or to Model Class as in :class:`django.db.models.ForeignKey` """
[docs]class HTMLField(TextField): """ Extends :class:`django.db.models.TextField`. A simple field for storing HTML markup. The field is based on :class:`django.db.models.TextField`, therefore it does not support indexing and is not recommended for use in filters. """
[docs]class WYSIWYGField(TextField): """ Extends :class:`django.db.models.TextField`. A simple field for storing Markdown data. The field is based on :class:`django.db.models.TextField`, therefore it does not support indexing and is not recommended for use in filters. """