django - 限制用户可以上传的文件数量

Question

我有一个多文件上传，并希望将用户限制为每个上传 3 次。我的问题是我需要知道一个 user 有多少个文件已经在数据库中创建以及他们当前上传的数量(他们可以一次上传多个文件，并且可以上传多次)。
我尝试了很多事情，包括:
创建 validator (验证器通过了正在添加的实际文件，而不是 model ，所以我无法访问 model 以获取它的 id 来调用 if StudentUploadedFile.objects.filter(student_lesson_data=data.id).count() >= 4: )。
在 clean(self): 中进行验证( clean 一次只传递一个实例，并且在清除所有文件之前不会更新数据库，因此我可以计算数据库中已有的文件，但无法计算当前正在上传的文件数量)。
使用 pre-save方法(如果在传递给我的 pre-save 方法的每个文件之间更新数据库，它会起作用，但只有在上传的所有文件都通过我的 pre-save 方法后才更新数据库)。
我的 post-save试图:

@receiver(pre_save, sender=StudentUploadedFile)
def upload_file_pre_save(sender, instance, **kwargs):

    if StudentUploadedFile.objects.filter(student_lesson_data=instance.data.id).count() >= 4:
        raise ValidationError('Sorry, you cannot upload more than three files')

编辑:
模型.py

class StudentUploadedFile(models.Model):
    student_lesson_data = models.ForeignKey(StudentLessonData, related_name='student_uploaded_file', on_delete=models.CASCADE)
    student_file = models.FileField(upload_to='module_student_files/', default=None)

View .py

class StudentUploadView(View):
    def get(self, request):
        files_list = StudentUploadedFile.objects.all()
        return render(self.request, 'users/modules.html', {'student_files': files_list})

    def post(self, request, *args, **kwargs):
        form = StudentUploadedFileForm(self.request.POST, self.request.FILES)
        form.instance.student_lesson_data_id = self.request.POST['student_lesson_data_id']

        if form.is_valid():
            uploaded_file = form.save()

            # pass uploaded_file data and username so new file can be added to students file list using ajax
            # lesson_id is used to output newly added file to corresponding newly_added_files div
            data = {'is_valid': True, 'username': request.user.username, 'file_id': uploaded_file.id, 'file_name': uploaded_file.filename(),
            'lesson_id': uploaded_file.student_lesson_data_id, 'file_path': str(uploaded_file.student_file)}
        else:
            data = {'is_valid': False}
        return JsonResponse(data)

模板文件

<form id='student_uploaded_file{{ item.instance.id }}'>
                                                {% csrf_token %}
                                                <a href="{% url 'download_student_uploaded_file' username=request.user.username file_path=item.instance.student_file %}" target='_blank'>{{ item.instance.filename }}</a>
                                                <a href="{% url 'delete_student_uploaded_file' username=request.user.username file_id=item.instance.id %}" class='delete' id='{{ item.instance.id }}'>Delete</a>
                                            </form>

js

$(function () {
    // open file explorer window
    $(".js-upload-photos").on('click', function(){
        // concatenates the id from the button pressed onto the end of fileupload class to call correct input element
        $("#fileupload" + this.id).click();
     });

    $('.fileupload_input').each(function() {
        $(this).fileupload({
            dataType: 'json',
            done: function(e, data) { // process response from server
            // add newly added files to students uploaded files list
            if (data.result.is_valid) {
                $("#newly_added_files" + data.result.lesson_id).prepend("<form id='student_uploaded_file" + data.result.file_id +
                "'><a href='/student_hub/" + data.result.username + "/download_student_uploaded_file/" +
                data.result.file_path + "' target='_blank'>" + data.result.file_name + "</a><a href='/student_hub/" + data.result.username +
                "/delete_student_uploaded_file/" + data.result.file_id + "/'  class='delete' id=" + data.result.file_id + ">Delete</a></form>")
            }
            }
        });
    });

更新:
表格.py

class StudentUploadedFileForm(forms.ModelForm):
    student_file = forms.FileField(widget=forms.ClearableFileInput(attrs={'multiple': True}))

查看.py

class StudentUploadView(View):
    model = StudentUploadedFile
    max_files_per_lesson = 3

    def post(self, request, *args, **kwargs):
        lesson_data_id = request.POST['student_lesson_data_id']
        current_files_count = self.model.objects.filter(
            student_lesson_data_id=lesson_data_id
        ).count()
        avail = self.max_files_per_lesson - current_files_count
        file_list = request.FILES.getlist('student_file')
        print(len(file_list))
        if avail - len(file_list) < 0:
            return JsonResponse(data={
                'is_valid': False,
                'reason': f'Too many files: you can only upload {avail}.'
            })
        else:
            for f in file_list:
                print(f)
                
        data = {'test': True}
        return JsonResponse(data)

谢谢你。

Answer 1

我试过使用 PyPi 包，它工作得很好。我将在这里冒险并假设您愿意编辑包代码以修复由于兼容性问题而遇到的任何错误，因为大多数在很长一段时间内没有更新的包可能会遇到它们。
解决限制用户上传文件数量的问题，django-multiuploader package 会有很大的帮助，老实说，它会做的比你要求的多。是的，它使用 JQuery 表单上传多个文件。
如何使用它？
安装和使用前步骤
安装

pip install django-multiuploader
python3 manage.py syncdb
python3 manage.py migrate multiuploader

在您的 settings.py文件 :

MULTIUPLOADER_FILES_FOLDER = ‘multiuploader’ # - media location where to store files

MULTIUPLOADER_FILE_EXPIRATION_TIME = 3600  # - time, when the file is expired (and it can be cleaned with clean_files command).

MULTIUPLOADER_FORMS_SETTINGS =

{
'default': {
    'FILE_TYPES' : ["txt","zip","jpg","jpeg","flv","png"],
    'CONTENT_TYPES' : [
            'image/jpeg',
            'image/png',
            'application/msword',
            'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
            'application/vnd.ms-excel',
            'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            'application/vnd.ms-powerpoint',
            'application/vnd.openxmlformats-officedocument.presentationml.presentation',
            'application/vnd.oasis.opendocument.text',
            'application/vnd.oasis.opendocument.spreadsheet',
            'application/vnd.oasis.opendocument.presentation',
            'text/plain',
            'text/rtf',
                ],
    'MAX_FILE_SIZE': 10485760,
    'MAX_FILE_NUMBER':5,
    'AUTO_UPLOAD': True,
},
'images':{
    'FILE_TYPES' : ['jpg', 'jpeg', 'png', 'gif', 'svg', 'bmp', 'tiff', 'ico' ],
    'CONTENT_TYPES' : [
        'image/gif',
        'image/jpeg',
        'image/pjpeg',
        'image/png',
        'image/svg+xml',
        'image/tiff',
        'image/vnd.microsoft.icon',
        'image/vnd.wap.wbmp',
        ],
    'MAX_FILE_SIZE': 10485760,
    'MAX_FILE_NUMBER':5,
    'AUTO_UPLOAD': True,
},
'video':{
    'FILE_TYPES' : ['flv', 'mpg', 'mpeg', 'mp4' ,'avi', 'mkv', 'ogg', 'wmv', 'mov', 'webm' ],
    'CONTENT_TYPES' : [
        'video/mpeg',
        'video/mp4',
        'video/ogg',
        'video/quicktime',
        'video/webm',
        'video/x-ms-wmv',
        'video/x-flv',
        ],
    'MAX_FILE_SIZE': 10485760,
    'MAX_FILE_NUMBER':5,
    'AUTO_UPLOAD': True,
},
'audio':{
    'FILE_TYPES' : ['mp3', 'mp4', 'ogg', 'wma', 'wax', 'wav', 'webm' ],
    'CONTENT_TYPES' : [
        'audio/basic',
        'audio/L24',
        'audio/mp4',
        'audio/mpeg',
        'audio/ogg',
        'audio/vorbis',
        'audio/x-ms-wma',
        'audio/x-ms-wax',
        'audio/vnd.rn-realaudio',
        'audio/vnd.wave',
        'audio/webm'
        ],
    'MAX_FILE_SIZE': 10485760,
    'MAX_FILE_NUMBER':5,
    'AUTO_UPLOAD': True,
}}

请注意 MAX_FILE_NUMBER ，就在他们的谎言中，你的问题的答案。安装后查看源代码，如果需要，请尝试自行实现。可能会很有趣。
请参阅进一步说明:
django-multiuploader package on pypi