如何遍历下拉模型表单字段以仅显示Django中的某些值

Question

我有4个选择

target = (('Week', 'Weekly target'),
          ('Day', 'Daily target'),
          ('Verify', 'Verify'),
          ('Done', 'Done'))

这是我实现选择的模型：

class GoalStatus(models.Model):

    target = models.CharField(max_length=100, choices=target, default="Week")
    name = models.ForeignKey(ScrummyUser, on_delete=models.CASCADE)
    goal_status = models.ForeignKey(ScrummyGoals, on_delete=models.CASCADE)

这是我的模特表格

class ChangeTaskForm(forms.ModelForm):

    class Meta:
        model = GoalStatus
        fields = '__all__'

这是我的html文件

{% if user.is_authenticated %}
{% if request.user|has_group:"ADMIN" %}

    <form action="{% url 'myapp:move_goal' %}"  method="post">
        {% csrf_token %}
        {% for field in form.data.target %}
            {% for foo in field %}
                {% if foo == Day %}
                    {{ foo }}
                {% endif %}
            {% endfor %}

        {% endfor %}
    </form>

我如何遍历表单中的下拉列表，以仅向有权选择“天”的用户显示所需的选择，例如“天”。 我是Django的新手。

Answer 1

在将表单发送到模板之前，所有逻辑都可以在后端（ your views ）中完成：

if request.user.groups.filter(name__iexact="ADMIN").exists():
    form.fields['target'].choices = ( ('Day', 'Daily target'))

由于您使用的是Django CBV，因此请重写get_form()方法

def get_form(self, *args, **kwargs):
    form = super(ClassBasedView, self).get_form(*args, **kwargs)
    if self.request.user.groups.filter(name__iexact="ADMIN").exists():
        form.fields['target'].choices = ( ('Day', 'Daily target'))
    return form

Answer 2

您可以在ModelForm（ 此处的ModelForm文档 ）中修改选择。

以您的形式：

from ____ import target # idk where your target variable is but it needs to be visible to your ChangeTaskForm in here. So you may have to import it.

class ChangeTaskForm(forms.ModelForm):

    class Meta:
        model = GoalStatus
        fields = '__all__'

    def __init__(self, *args, **kwargs):
        super(ChangeTaskForm, self).__init__(*args, **kwargs)
        self.initialize_widgets()

    def initialize_widgets(self):
        """
        Initializes widgets for the form. This is not a built in
        method. It's a method I'm adding. You can manipulate any field 
        in the form along with their widgets. This is where the choices 
        can be filtered down from the overall choices to specific 
        choices.
        """
        target_choices_for_field = []
        for target_option_tuple in target: # loop through each option.
            can_choose_option = ... # This is where you do the logic to determine whether or not the option should be available.
            if can_choose_option:
                target_choices_for_field.append(target_option_tuple)
        self.fields["target"].widget = forms.Select(choices=target_choices_for_field)

然后，在您的html中：

{% if user.is_authenticated %}
{% if request.user|has_group:"ADMIN" %}

<form action="{% url 'myapp:move_goal' %}"  method="post">
    {% csrf_token %}
    {% form %}
    <input type="submit" value="submit">Submit</input>
</form>

现在，ModelForm已经处理了过滤代码中的选项，因此您无需在模板中对此做任何事情。 通常最好将这样的逻辑尽可能往下推。 因此，应该在表单类而不是模板中设置表单选择。 附带说明一下，您的验证应执行相同的操作（将逻辑推得尽可能低）。 将视图修饰符与@user_passes_test一起使用以处理组以进行身份​​验证。