UpdateView不使用现有数据填充表单 [英] UpdateView not populating form with existing data

问题描述

所以我将UpdateView设置为向表单发送请求对象，以便我可以修改表单中的查询集（基于 request .user ）

So I have my UpdateView set up to send a request object to the form so I can modify a queryset in the form (based on request.user)

我的views.py：

my views.py:

class DataSourceUpdateView(UpdateView):
    model = DataSource
    form_class = DataSourceForm
    template_name = 'engine/datasource_update.html'

    def get(self, request, *args, **kwargs):

        obj = DataSource.objects.get(pk=kwargs['pk'])
        self.object = None
        form = DataSourceForm(request)
        return self.render_to_response(
            self.get_context_data(form=form,
                                  object=obj))

    def post(self, request, *args, **kwargs):

        form = DataSourceForm(request, request.POST, request.FILES)

        if form.is_valid:
            return self.form_valid(form)
        else:
            return self.form_invalid(form)  

我的form.py：

class DataSourceForm(forms.ModelForm):

    def __init__(self, request, *args, **kwargs):
        self.request = request
        super(DataSourceForm, self).__init__(*args, **kwargs)  
        self.fields['dataset_request'].queryset = DatasetRequest.objects.filter(
            creator=self.request.user)

    class Meta:
        model = DataSource
        exclude = ('creator', 'vote_score', 'num_vote_up',
                   'num_vote_down', 'file_size', 'slug')

我的问题是，在模板中，该表格未填充与现有的值。我该如何解决？

My problem is, in the template, the form is not populated with existing values. How can I fix this?

推荐答案

使用 UpdateView 有点棘手的。因此，为了初始化表单的数据，您需要在视图本身而不是表单中进行操作。

With UpdateView it's a little bit tricky. So, in order to initialize your form's data, you need to do it in the view itself not in the form.

所以这是您可以执行的操作在使用 UpdateView 时完成的：

So here is how you can perform what's you've done when using UpdateView:

class DataSourceUpdateView(UpdateView):
    model = DataSource
    form_class = DataSourceForm
    template_name = 'engine/datasource_update.html'
    # An empty dict or add an initial data to your form
    initial = {}
    # And don't forget your success URL
    # or use reverse_lazy by URL's name
    # Or better, override get_success_url() method
    # And return your success URL using reverse_lazy
    sucess_url = '/' 

    def get_initial(self):
        """initialize your's form values here"""

        base_initial = super().get_initial()
        # So here you're initiazing you're form's data
        base_initial['dataset_request'] = DatasetRequest.objects.filter(
            creator=self.request.user
        )
        return base_initial

        #... The rest of your view logic

您的表单将是：

class DataSourceForm(forms.ModelForm):

    class Meta:
        model = DataSource
        exclude = (
            'creator',
            'vote_score',
            'num_vote_up',
            'num_vote_down',
            'file_size',
            'slug'
        )

奖金：

为了理解为什么需要初始化表单数据，需要来查看访问的 UpdateView的MRO此文档链接：

In order to understand why you need to initialize the form's data, you need to see the `UpdateView's MRO which are Visit this documentation link:

• ...


• django.views .generic.edit.FormMixin ＃=> e正在处理以下形式


• ...

• ...
• django.views.generic.edit.FormMixin # => This one is dealing with the form
• ...

和 FormMixin 具有以下属性和方法访问文档链接：

And the FormMixin have these attributes and methods visit the documentation link which are:

• 初始：包含以下内容的字典表格的初始数据。
  ...


• get_initial（）：检索表单的初始数据。默认情况下，返回首字母的副本。

• initial: A dictionary containing initial data for the form. ...
• get_initial(): Retrieve initial data for the form. By default, returns a copy of initial.

我也建议您查看 FormMixin 具有相似的属性和方法，以了解如何覆盖它们或让Django为您做魔术：D。请参见此文档链接

Also i recommend you to see what the FormMixin have like attributes and methods in order to see how you can override them or let Django do magics for you :D. See this documentation link

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