如何在两个视图之间传递一组对象？

Question

我正在构建一个测验应用程序，通过创建一个模型类将问题存储在数据库中。我从数据库中检索每个用户的随机问题集，然后将它们呈现在HTML页面上。问题是，在用户登录后，会出现一组随机问题，但在刷新页面后，这组随机问题就会丢失。在登录用户并将其作为字典传递给另一个视图之后，我认为如何解决在另一个view....say中检索对象集的问题。但是我找不到语法或任何函数(如果存在的话)。请帮帮忙。我使用Django3.1和MySQL作为我的数据库。我的views.py看起来像这样：

from django.shortcuts import render, redirect
from .models import *
from .forms import UserForm
from django.contrib.auth.forms import AuthenticationForm
import random
from django.contrib.auth import login, logout, authenticate

# Create your views here.
def home(request):
    return render(request, 'testapp/home.html')

def loginuser(request):
    #form = UserForm()
    if request.method == 'GET':
        form = AuthenticationForm()
        return render(request, 'testapp/login.html', {'form':form})
    else:
        user = authenticate(request, username=request.POST['username'], password=request.POST['password'])
        if user is None:
            return render(request, 'testapp/login.html', {'form':AuthenticationForm(), 'error':'Username or password incorrect'})
        else:
            login(request, user)
            return redirect('paper')

def paper(request):
    #objects = Questions.objects.all()
    """count = Questions.objects.all().count()
    slice = random.random() * (count-5)
    objects = Questions.objects.all()[slice:slice+5]"""
    #objects = {{ objects }}
    objects = Questions.objects.all().order_by('?')[:5]
    return render(request, 'testapp/paper.html', {'objects':objects})

Answer 1

在args或kwargs等视图之间传递值并不是真正的直接方法。我建议使用请求会话来存储值并再次访问它们。

def paper(request):
    question_set = Questions.object.all()
    question_set = question_set.order_by('?')[:5]

    # Retrieve the primary keys from the 5 questions selected.
    question_pks = question_set.values_list('pk', flat=True)
    # Store the pks in a list on the request session.
    request.session['question_ids'] = list(question_pks)

    context_data = {'objects': question_set}
    return render(request, 'testapp/paper.html', context_data)


def home(request):
    # Get all the pks from the request session again.
    question_pks = request.session['question_ids']
    # Use the pks to retrieve the same question objects from the database.
    question_set = Questions.objects.filter(pk__in=question_pks)

    context_data = {'objects': question_set}
    return render(request, 'testapp/home.html', context_data)

Answer 2

您可以在第一次使用request.session存储您的问题ids：

def paper(request):
    if 'question_ids' not in request.session:
        request.session['question_ids'] = list(Questions.objects.all().order_by('?').values_list('id', flat=True)[:5])
    objects = Questions.objects.filter(id__in=request.session['question_ids'])
    return render(request, 'testapp/paper.html', {'objects':objects})