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django - 如何在 Django 项目中将请求传递给 Celery 任务参数？

问题描述

我正在使用wkhtmltopdfDjango 生成 PDF 文件并将其通过电子邮件发送给某人。这是我的看法：

class ChallanEmail(AtomicMixin, View, LoginRequiredMixin):
    template = "europarts/challan/email_template.html"

    def get(self, request, **kwargs):
        challan = Challan.objects.get(pk=kwargs['pk'])
        ref_no = challan.ref_no
        date = challan.created
        recipient = challan.recipient
        address = challan.recipient_address
        challan_rows = ChallanRow.objects.filter(challan=challan)

        context = {
            "ref_no": ref_no,
            "date": date,
            "recipient": recipient,
            "address": address,
            "challan_rows": challan_rows,
        }

        response = PDFTemplateResponse(
            request=request,
            template=self.template,
            filename='challan_email.pdf',
            context=context,
            show_content_in_browser=True,
            cmd_options={'margin-top': 10,
                         'zoom': 1,
                         'viewport-size': '1366 x 513',
                         'javascript-delay': 1000,
                         'no-stop-slow-scripts': True},
        )

        file_path = os.path.join(settings.BASE_DIR, settings.MEDIA_ROOT, 'challan_email.pdf')
        with open(file_path, 'wb') as f:
            f.write(response.rendered_content)

        subject = 'From Design Ace Limited'
        body = self.request.GET.get('email_body', '')
        from_email = 'Sorower Hossain <sorower@europartsbd.com>'
        to = ['{}'.format(self.request.GET.get('to_address'))]
        attachment = os.path.join(settings.MEDIA_ROOT, 'challan_email.pdf')

        send_email(subject, body, from_email, to, attachment)

        return HttpResponseRedirect(reverse('europarts:challan_details', args=(kwargs['pk'],)))

正如您在最后看到的那样，我正在发送带有任务 ( send_email) 的电子邮件，使用celery. 但是，最耗时的过程是 PDF 创建过程。这是执行此操作的代码部分：

response = PDFTemplateResponse(
    request=request,
    template=self.template,
    filename='challan_email.pdf',
    context=context,
    show_content_in_browser=True,
    cmd_options={'margin-top': 10,
                 'zoom': 1,
                 'viewport-size': '1366 x 513',
                 'javascript-delay': 1000,
                 'no-stop-slow-scripts': True},
    )

我面临的问题是，每当我尝试将所有参数传输到 celery 任务时，它都会显示错误，因为request它不可序列化。如何将请求转移到我的 celery 任务并节省 PDF 生成时间？这项任务几乎需要三秒钟，这非常多。

标签： djangotaskcelery

解决方案

如果您PDFTemplateResponse仅用于生成 pdf 文件并通过电子邮件发送（而不是作为 http 响应），则可以在 celery 任务中模拟它。

您的芹菜任务，在<app_name>/tasks.py文件中：

from django.test.client import RequestFactory
# other necessary imports
...

@shared_task
def create_pdf_and_send_email(template, context, email_body, to_address):
    request = RequestFactory().get('') # any valid url
    challan_rows = ChallanRow.objects.filter(pk__in=context['challan_rows'])
    context['challan_rows'] = challan_rows
    response = PDFTemplateResponse(
            request=request,
            template=template,
            filename='challan_email.pdf',
            context=context,
            show_content_in_browser=True,
            cmd_options={'margin-top': 10,
                         'zoom': 1,
                         'viewport-size': '1366 x 513',
                         'javascript-delay': 1000,
                         'no-stop-slow-scripts': True},
        )

        file_path = os.path.join(settings.BASE_DIR, settings.MEDIA_ROOT, 'challan_email.pdf')
        with open(file_path, 'wb') as f:
            f.write(response.rendered_content)

        subject = 'From Design Ace Limited'
        body = email_body
        from_email = 'Sorower Hossain <sorower@europartsbd.com>'
        to = ['{}'.format(to_address)]
        attachment = os.path.join(settings.MEDIA_ROOT, 'challan_email.pdf')
        send_email(subject, body, from_email, to, attachment)

而你的重构get方法：

from .tasks import create_pdf_and_send_email
...
def get(self, request, **kwargs):
    challan = Challan.objects.get(pk=kwargs['pk'])
    ref_no = challan.ref_no
    date = challan.created
    recipient = challan.recipient
    address = challan.recipient_address
    challan_rows = ChallanRow.objects.filter(challan=challan).values_list('pk', flat=True)

    context = {
        "ref_no": ref_no,
        "date": date,
        "recipient": recipient,
        "address": address,
        "challan_rows": challan_rows,
    }

    email_body = self.request.GET.get('email_body', '')
    to_address = self.request.GET.get('to_address')
    create_pdf_and_send_email.delay(template, context, email_body, to_address)
    return HttpResponseRedirect(reverse('europarts:challan_details', args=(kwargs['pk'],)))

我希望它应该有效。

如果序列化错误有任何问题（可能与变量中的address字段有关），请更改为in方法。然后，在 celery 任务中，使用给定的 pk 检索地址（例如，并替换为.contextaddress = challan.recipient_addressaddress = challan.recipient_address.pkgetaddress = YourAddressModel.objects.get(pk=context['address'])context['address']context['address'] = address

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