Django:在基于类的 ListView 中搜索表单 [英] Django: Search form in Class Based ListView

问题描述

我正在尝试实现一个 Class Based ListView，它显示了一个表集的选择.如果第一次请求该站点，则应显示数据集.我更喜欢 POST 提交，但 GET 也可以.

I am trying to realize a Class Based ListView which displays a selection of a table set. If the site is requested the first time, the dataset should be displayed. I would prefer a POST submission, but GET is also fine.

这是一个问题，使用基于函数的视图很容易处理，但是对于基于类的视图，我很难理解.

That is a problem, which was easy to handle with function based views, however with class based views I have a hard time to get my head around.

我的问题是我收到了各种各样的错误，这是由于我对基于分类的视图的理解有限造成的.我已经阅读了各种文档并且我了解直接查询请求的视图，但是一旦我想在查询语句中添加一个表单，我就会遇到不同的错误.对于下面的代码，我收到一个 ValueError: Cannot use None as a query value.

My problem is that I get a various number of error, which are caused by my limited understanding of the classed based views. I have read various documentations and I understand views for direct query requests, but as soon as I would like to add a form to the query statement, I run into different error. For the code below, I receive an ValueError: Cannot use None as a query value.

根据表单条目(否则选择整个数据库)的基于类的 ListView 的最佳实践工作流程是什么?

这是我的示例代码:

models.py

class Profile(models.Model):
    name = models.CharField(_('Name'), max_length=255)

    def __unicode__(self):
        return '%name' % {'name': self.name}

    @staticmethod
    def get_queryset(params):

        date_created = params.get('date_created')
        keyword = params.get('keyword')
        qset = Q(pk__gt = 0)
        if keyword:
            qset &= Q(title__icontains = keyword)
        if date_created:
            qset &= Q(date_created__gte = date_created)
        return qset

forms.py

class ProfileSearchForm(forms.Form):
    name = forms.CharField(required=False)

views.py

class ProfileList(ListView):
    model = Profile
    form_class = ProfileSearchForm
    context_object_name = 'profiles'
    template_name = 'pages/profile/list_profiles.html'
    profiles = []


    def post(self, request, *args, **kwargs):
        self.show_results = False
        self.object_list = self.get_queryset()
        form = form_class(self.request.POST or None)
        if form.is_valid():
            self.show_results = True
            self.profiles = Profile.objects.filter(name__icontains=form.cleaned_data['name'])
        else:
            self.profiles = Profile.objects.all()
        return self.render_to_response(self.get_context_data(object_list=self.object_list, form=form))

    def get_context_data(self, **kwargs):
        context = super(ProfileList, self).get_context_data(**kwargs)
        if not self.profiles:
            self.profiles = Profile.objects.all()
        context.update({
            'profiles': self.profiles
        })
        return context

下面我添加了完成这项工作的 FBV.如何将此功能转换为 CBV?在基于函数的视图中似乎很简单，但在基于类的视图中则不然.

Below I added the FBV which does the job. How can I translate this functionality into a CBV? It seems to be so simple in function based views, but not in class based views.

def list_profiles(request):
    form_class = ProfileSearchForm
    model = Profile
    template_name = 'pages/profile/list_profiles.html'
    paginate_by = 10

    form = form_class(request.POST or None)
    if form.is_valid():
        profile_list = model.objects.filter(name__icontains=form.cleaned_data['name'])
    else:
        profile_list = model.objects.all()

    paginator = Paginator(profile_list, 10) # Show 10 contacts per page
    page = request.GET.get('page')
    try:
        profiles = paginator.page(page)
    except PageNotAnInteger:
        profiles = paginator.page(1)
    except EmptyPage:
        profiles = paginator.page(paginator.num_pages)

    return render_to_response(template_name, 
            {'form': form, 'profiles': suppliers,}, 
            context_instance=RequestContext(request))

推荐答案

我认为您的目标是尝试根据表单提交过滤查询集，如果是这样，请使用 GET :

I think your goal is trying to filter queryset based on form submission, if so, by using GET :

class ProfileSearchView(ListView)
    template_name = '/your/template.html'
    model = Person

    def get_queryset(self):
        name = self.kwargs.get('name', '')
        object_list = self.model.objects.all()
        if name:
            object_list = object_list.filter(name__icontains=name)
        return object_list

然后您需要做的就是编写一个 get 方法来呈现模板和上下文.

Then all you need to do is write a get method to render template and context.

也许不是最好的方法.通过使用上面的代码，你不需要定义一个 Django 表单.

Maybe not the best approach. By using the code above, you no need define a Django form.

这是它的工作原理:基于类的视图将其呈现模板、处理表单等的方式分开.例如，get 处理 GET 响应，post 处理 POST 响应，get_queryset 和 get_object 是不言自明的，等等.了解可用方法的简单方法是启动 shell 并输入:

Here's how it works : Class based views separates its way to render template, to process form and so on. Like, get handles GET response, post handles POST response, get_queryset and get_object is self explanatory, and so on. The easy way to know what's method available, fire up a shell and type :

from django.views.generic import ListView 如果你想了解ListView

然后输入dir(ListView).在那里您可以看到所有定义的方法并访问源代码以了解它.用于获取查询集的 get_queryset 方法.为什么不这样定义它，它也可以工作:

and then type dir(ListView). There you can see all the method defined and go visit the source code to understand it. The get_queryset method used to get a queryset. Why not just define it like this, it works too :

class FooView(ListView):
    template_name = 'foo.html'
    queryset = Photo.objects.all()  # or anything

我们可以像上面那样做，但是我们不能用那种方法来做动态过滤.通过使用get_queryset，我们可以进行动态过滤，使用我们拥有的任何数据/值/信息，这意味着我们也可以使用GET<发送的name参数/code>，它在 kwargs 上可用，或者在这种情况下，在 self.kwargs[some_key"] 上可用，其中 some_key 是任何您指定的参数

We can do it like above, but we can't do dynamic filtering by using that approach. By using get_queryset we can do dynamic filtering, using any data/value/information we have, it means we also can use name parameter that is sent by GET, and it's available on kwargs, or in this case, on self.kwargs["some_key"] where some_key is any parameter you specified

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