Mongoengine FileField保存到磁盤？

Question

Mongoengine將FileField和ImageField存儲到GridFS。什麼是最簡單的方法來複制原始文件/圖像領域的功能？編輯：

所以這是我現在的班級。我可以加載文件並將其保存到磁盤，Mongo保存數據庫中文件的路徑。

我摔倒在「to_python」，因爲我認爲它需要創建一個proxy_class的對象，但我不明白如何，如果我所得到的是文件的路徑（作爲值傳遞在）。

import os 
import datetime 

from mongoengine.python_support import str_types 
from django.db.models.fields.files import FieldFile 
from django.core.files.base import File 
from django.core.files.storage import default_storage 
from mongoengine.base import BaseField 
from mongoengine.connection import get_db, DEFAULT_CONNECTION_NAME 
from django.utils.encoding import force_text 
#from django.utils.encoding import force_str 


class DJFileField(BaseField): 

    proxy_class = FieldFile 

    def __init__(self, 
       db_alias=DEFAULT_CONNECTION_NAME, 
       name=None, 
       upload_to='', 
       storage=None, 
       **kwargs): 

     self.db_alias = db_alias 
     self.storage = storage or default_storage 
     self.upload_to = upload_to 

     if callable(upload_to): 
      self.generate_filename = upload_to 

     super(DJFileField, self).__init__(**kwargs) 


    def __get__(self, instance, owner): 
     # Lots of information on whats going on here can be found 
     # on Django's FieldFile implementation, go over to GitHub to 
     # read it. 
     file = instance._data.get(self.name) 

     if isinstance(file, str_types) or file is None: 
      attr = self.proxy_class(instance, self, file) 
      instance._data[self.name] = attr 

     elif isinstance(file, File) and not isinstance(file, FieldFile): 
      file_copy = self.proxy_class(instance, self, file.name) 
      file_copy.file = file 
      file_copy._committed = False 
      instance._data[self.name] = file_copy 

     elif isinstance(file, FieldFile) and not hasattr(file, 'field'): 
      file.instance = instance 
      file.field = self 
      file.storage = self.storage 

     # That was fun, wasn't it? 
     return instance._data[self.name] 


    def __set__(self, instance, value): 
     instance._data[self.name] = value 

    # The 3 methods below get used by the FieldFile proxy_object 
    def get_directory_name(self): 
     return os.path.normpath(force_text(datetime.datetime.now().strftime(self.upload_to))) 

    def get_filename(self, filename): 
     return os.path.normpath(self.storage.get_valid_name(os.path.basename(filename))) 

    def generate_filename(self, instance, filename): 
     return os.path.join(self.get_directory_name(), self.get_filename(filename)) 


    def to_mongo(self, value): 
    # Store the path in MongoDB 
    # I also used this bit to actually save the file to disk. 
    # The value I'm getting here is a FileFiled and it all looks 
    # pretty good at this stage even though I'm not 100% sure 
    # of what's going on. 

     import ipdb; ipdb.set_trace() 

     if not value._committed and value is not None: 
      value.save(value.name, value) 
      return value.path 

     return value.path  


    def to_python(self, value): 
     # Now this is the real problem, value is the path that got saved 
     # in mongo. No idea how to return a FileField obj from here. 
     # self.instance and instance throw errors. 

Answer 1

我認爲這將是一個很好的補充 - 或許稱爲LocalFileField，使之更加框架不可知，如果你提供的測試和文檔將成爲一位偉大的除了https://github.com/MongoEngine/extras-mongoengine

我的唯一原因沒有在覈心中銷售它 - 如果您正在運行復制集，該文件仍然只能存儲在一個節點上。