OpenSlides/openslides/mediafiles/models.py
2019-07-12 13:08:07 +02:00

237 lines
7.5 KiB
Python

import os
import uuid
from typing import List, cast
from django.conf import settings
from django.db import models
from ..agenda.mixins import ListOfSpeakersMixin
from ..core.config import config
from ..utils.models import RESTModelMixin
from ..utils.rest_api import ValidationError
from .access_permissions import MediafileAccessPermissions
class MediafileManager(models.Manager):
"""
Customized model manager to support our get_full_queryset method.
"""
def get_full_queryset(self):
"""
Returns the normal queryset with all mediafiles. In the background
all related list of speakers are prefetched from the database.
"""
return self.get_queryset().prefetch_related(
"lists_of_speakers", "parent", "access_groups"
)
def delete(self, *args, **kwargs):
raise RuntimeError(
"Do not use the querysets delete function. Please delete every mediafile on it's own."
)
def get_file_path(mediafile, filename):
mediafile.original_filename = filename
ext = filename.split(".")[-1]
filename = "%s.%s" % (uuid.uuid4(), ext)
return os.path.join("file", filename)
class Mediafile(RESTModelMixin, ListOfSpeakersMixin, models.Model):
"""
Class for uploaded files which can be delivered under a certain url.
"""
objects = MediafileManager()
access_permissions = MediafileAccessPermissions()
can_see_permission = "mediafiles.can_see"
mediafile = models.FileField(upload_to=get_file_path, null=True)
"""
See https://docs.djangoproject.com/en/dev/ref/models/fields/#filefield
for more information.
"""
title = models.CharField(max_length=255)
"""A string representing the title of the file."""
original_filename = models.CharField(max_length=255)
create_timestamp = models.DateTimeField(auto_now_add=True)
"""A DateTimeField to save the upload date and time."""
is_directory = models.BooleanField(default=False)
parent = models.ForeignKey(
"self",
# The on_delete should be CASCADE_AND_AUTOUPDATE, but we do
# have to delete the actual file from every mediafile to ensure
# cleaning up the server files. This is ensured by the custom delete
# method of every mediafile. Do not use the delete method of the
# mediafile manager.
on_delete=models.SET_NULL,
null=True,
blank=True,
related_name="children",
)
access_groups = models.ManyToManyField(settings.AUTH_GROUP_MODEL, blank=True)
class Meta:
"""
Meta class for the mediafile model.
"""
ordering = ("title",)
default_permissions = ()
permissions = (
("can_see", "Can see the list of files"),
("can_manage", "Can manage files"),
)
def create(self, *args, **kwargs):
self.validate_unique()
return super().create(*args, **kwargs)
def save(self, *args, **kwargs):
self.validate_unique()
return super().save(*args, **kwargs)
def validate_unique(self):
"""
`unique_together` is not working with foreign keys with possible `null` values.
So we do need to check this here.
"""
if (
Mediafile.objects.exclude(pk=self.pk)
.filter(title=self.title, parent=self.parent)
.exists()
):
raise ValidationError(
{"detail": "A mediafile with this title already exists in this folder."}
)
def __str__(self):
"""
Method for representation.
"""
return self.title
def delete(self, skip_autoupdate=False):
mediafiles_to_delete = self.get_children_deep()
mediafiles_to_delete.append(self)
for mediafile in mediafiles_to_delete:
if mediafile.is_file:
# To avoid Django calling save() and triggering autoupdate we do not
# use the builtin method mediafile.mediafile.delete() but call
# mediafile.mediafile.storage.delete(...) directly. This may have
# unattended side effects so be careful especially when accessing files
# on server via Django methods (file, open(), save(), ...).
mediafile.mediafile.storage.delete(mediafile.mediafile.name)
mediafile._db_delete(skip_autoupdate=skip_autoupdate)
def _db_delete(self, *args, **kwargs):
""" Captures the original .delete() method. """
return super().delete(*args, **kwargs)
def get_children_deep(self):
""" Returns all children and all children of childrens and so forth. """
children = []
for child in self.children.all():
children.append(child)
children.extend(child.get_children_deep())
return children
@property
def path(self):
name = (self.title + "/") if self.is_directory else self.original_filename
if self.parent:
return self.parent.path + name
else:
return name
@property
def url(self):
return settings.MEDIA_URL + self.path
@property
def inherited_access_groups_id(self):
"""
True: all groups
False: no permissions
List[int]: Groups with permissions
"""
own_access_groups = [group.id for group in self.access_groups.all()]
if not self.parent:
return own_access_groups or True # either some groups or all
access_groups = self.parent.inherited_access_groups_id
if len(own_access_groups) > 0:
if isinstance(access_groups, bool) and access_groups:
return own_access_groups
elif isinstance(access_groups, bool) and not access_groups:
return False
else: # List[int]
access_groups = [
id
for id in cast(List[int], access_groups)
if id in own_access_groups
]
return access_groups or False
else:
return access_groups # We do not have restrictions, copy from parent.
def get_filesize(self):
"""
Transforms bytes to kilobytes or megabytes. Returns the size as string.
"""
# TODO: Read http://stackoverflow.com/a/1094933 and think about it.
try:
size = self.mediafile.size
except OSError:
size_string = "unknown"
except ValueError:
# happens, if this is a directory and no file exists
return None
else:
if size < 1024:
size_string = "< 1 kB"
elif size >= 1024 * 1024:
mB = size / 1024 / 1024
size_string = "%d MB" % mB
else:
kB = size / 1024
size_string = "%d kB" % kB
return size_string
@property
def is_logo(self):
if self.is_directory:
return False
for key in config["logos_available"]:
if config[key]["path"] == self.url:
return True
return False
@property
def is_font(self):
if self.is_directory:
return False
for key in config["fonts_available"]:
if config[key]["path"] == self.url:
return True
return False
@property
def is_special_file(self):
return self.is_logo or self.is_font
@property
def is_file(self):
return not self.is_directory
def get_list_of_speakers_title_information(self):
return {"title": self.title}