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

130 lines
4.3 KiB
Python

import mimetypes
from django.conf import settings
from django.db import models as dbmodels
from PyPDF2 import PdfFileReader
from PyPDF2.utils import PdfReadError
from ..utils.auth import get_group_model
from ..utils.rest_api import (
FileField,
IdPrimaryKeyRelatedField,
ModelSerializer,
SerializerMethodField,
ValidationError,
)
from .models import Mediafile
class AngularCompatibleFileField(FileField):
def to_internal_value(self, data):
if data == "":
return None
return super(AngularCompatibleFileField, self).to_internal_value(data)
def to_representation(self, value):
if value is None or value.name is None:
return None
filetype = mimetypes.guess_type(value.name)[0]
result = {"name": value.name, "type": filetype}
if filetype == "application/pdf":
try:
if (
settings.DEFAULT_FILE_STORAGE
== "storages.backends.sftpstorage.SFTPStorage"
):
remote_path = value.storage._remote_path(value.name)
file_handle = value.storage.sftp.open(remote_path, mode="rb")
else:
file_handle = open(value.path, "rb")
result["pages"] = PdfFileReader(file_handle).getNumPages()
except FileNotFoundError:
# File was deleted from server. Set 'pages' to 0.
result["pages"] = 0
except PdfReadError:
# File could be encrypted but not be detected by PyPDF.
result["pages"] = 0
result["encrypted"] = True
return result
class MediafileSerializer(ModelSerializer):
"""
Serializer for mediafile.models.Mediafile objects.
"""
media_url_prefix = SerializerMethodField()
filesize = SerializerMethodField()
access_groups = IdPrimaryKeyRelatedField(
many=True, required=False, queryset=get_group_model().objects.all()
)
def __init__(self, *args, **kwargs):
"""
This constructor overwrites the FileField field serializer to return the file meta data in a way that the
angualarjs upload module likes
"""
super(MediafileSerializer, self).__init__(*args, **kwargs)
self.serializer_field_mapping[dbmodels.FileField] = AngularCompatibleFileField
# Make some fields read-oinly for updates (not creation)
if self.instance is not None:
self.fields["mediafile"].read_only = True
class Meta:
model = Mediafile
fields = (
"id",
"title",
"mediafile",
"media_url_prefix",
"filesize",
"access_groups",
"create_timestamp",
"is_directory",
"path",
"parent",
"list_of_speakers_id",
"inherited_access_groups_id",
)
read_only_fields = ("path",)
def validate(self, data):
title = data.get("title")
if title is not None and not title:
raise ValidationError({"detail": "The title must not be empty"})
parent = data.get("parent")
if parent and not parent.is_directory:
raise ValidationError({"detail": "parent must be a directory."})
if data.get("is_directory") and "/" in data.get("title", ""):
raise ValidationError(
{"detail": 'The name contains invalid characters: "/"'}
)
return super().validate(data)
def create(self, validated_data):
access_groups = validated_data.pop("access_groups", [])
mediafile = super().create(validated_data)
mediafile.access_groups.set(access_groups)
mediafile.save()
return mediafile
def update(self, instance, validated_data):
# remove is_directory, create_timestamp and parent from validated_data
# to prevent updating them (mediafile is ensured in the constructor)
validated_data.pop("is_directory", None)
validated_data.pop("create_timestamp", None)
validated_data.pop("parent", None)
return super().update(instance, validated_data)
def get_filesize(self, mediafile):
return mediafile.get_filesize()
def get_media_url_prefix(self, mediafile):
return settings.MEDIA_URL