权威性选择forms.py

Question

选我已经在这个question阅读代码和好看。 但如果我有用户身份验证，并且我希望用户只选择您的odjects如何更改该代码？为ex选择您的个人上传图像。

from django.forms.widgets import Select 
    class ProvinceForm(ModelForm): 
     class Meta: 
      CHOICES = Province.objects.all() 

      model = Province 
      fields = ('name',) 
      widgets = { 
       'name': Select(choices=((x.id, x.name) for x in CHOICES)), 
      } 

我的模型：

class MyModel(models.Model): 
    user = models.ForeignKey(User, unique=True) 
    upload = models.ImageField(upload_to='images') 

Answer 1

当你实例化视图中的表格，你应该通过user对象，这样my_form = MyModelForm(user=request.user)。

然后建立自己的MyModelForm：

# forms.py 

from django.forms import ModelForm 
from django.forms.widgets import Select 

class MyModelForm(ModelForm): 
    def __init__(self, *args, **kwargs): 
     # extract "user" value from kwrags (passed through form init). If there's no "user" keyword, just set self.user to an empty string. 
     self.user = kwargs.pop('user', '') 
     super(MyModelForm, self).__init__(*args, **kwargs) 
     if self.user: 
      # generate the choices as (value, display). Display is the one that'll be shown to user, value is the one that'll be sent upon submitting (the "value" attribute of <option>) 
      choices = MyModel.objects.filter(user=self.user).values_list('id', 'upload') 
      self.fields['upload'].widget = Select(choices=choices) 

    class Meta: 
     model = MyModel 
     fields = ('upload',) 

现在，每当你实例的形式与user关键字参数（my_form = MyModelForm(user=request.user)），这种形式将呈现这样的（在你的模板写它像{{ my_form }}）：

<select> 
    <option value="the_id_of_the_MyModel_model">upload_name</option> 
    <option value="the_id_of_the_MyModel_model">upload_name</option> 
    ... 
</select> 

最后，为了在下拉菜单中显示图像（请记住，“value”是在提交表单时将被发送回服务器的数据，而显示一个ju st用于UX），请拨打a look here。

[更新]：如何做到这一点在你的views.py

# views.py 

def my_view(request): 
    my_form = MyModelForm(user=request.user) 
    if request.method == 'POST': 
     my_form = MyModelForm(request.POST, user=request.user) 
     if my_form.is_valid(): 
      # ['upload'] should be the name of the <select> here, i.e if <select name="whatever"> then this should be "whatever" 
      pk = my_form.cleaned_data['upload'] 
      # image, now, is the value of the option selected (that is, the id of the object) 
      obj = MyModel.objects.get(id=pk) 
      print(obj.upload.url) # this should print the image's path 
    return render(request, 'path/to/template.html', {'my_form': my_form})