在Django表单中,我如何使字段只读(或禁用)?

当使用表单创建新条目时,应该启用所有字段——但当记录处于更新模式时,某些字段需要为只读。

例如,当创建一个新的Item模型时,所有字段都必须是可编辑的,但是在更新记录时,是否有一种方法禁用sku字段,使其可见,但不能编辑?

class Item(models.Model):
    sku = models.CharField(max_length=50)
    description = models.CharField(max_length=200)
    added_by = models.ForeignKey(User)


class ItemForm(ModelForm):
    class Meta:
        model = Item
        exclude = ('added_by')

def new_item_view(request):
    if request.method == 'POST':
        form = ItemForm(request.POST)
        # Validate and save
    else:
            form = ItemForm()
    # Render the view

ItemForm类可以重用吗?ItemForm或Item模型类需要做哪些更改?我是否需要编写另一个类“ItemUpdateForm”来更新项目?

def update_item_view(request):
    if request.method == 'POST':
        form = ItemUpdateForm(request.POST)
        # Validate and save
    else:
        form = ItemUpdateForm()

当前回答

在小部件上设置readonly只会使浏览器中的输入变为只读。添加一个返回实例的clean_sku。Sku确保字段值不会在表单级别上改变。

def clean_sku(self):
    if self.instance: 
        return self.instance.sku
    else: 
        return self.fields['sku']

这样您就可以使用model的(未修改的保存)并避免获得字段所需的错误。

其他回答

从禁用字段mixin开始:

class ModelAllDisabledFormMixin(forms.ModelForm):
    def __init__(self, *args, **kwargs):
    '''
    This mixin to ModelForm disables all fields. Useful to have detail view based on model
    '''
    super().__init__(*args, **kwargs)
    form_fields = self.fields
    for key in form_fields.keys():
        form_fields[key].disabled = True

然后:

class MyModelAllDisabledForm(ModelAllDisabledFormMixin, forms.ModelForm):
    class Meta:
        model = MyModel
        fields = '__all__'

准备视图:

class MyModelDetailView(LoginRequiredMixin, UpdateView):
    model = MyModel
    template_name = 'my_model_detail.html'
    form_class = MyModelAllDisabledForm

把它放在my_model_detail.html模板中:

  <div class="form">
     <form method="POST" enctype="multipart/form-data">
         {% csrf_token %}
         {{ form | crispy }}
     </form>
  </div>

您将获得与更新视图中相同的表单,但禁用了所有字段。

我做了一个MixIn类,你可以继承能够添加一个read_only iterable字段,将禁用和安全的字段在非第一次编辑:

(根据Daniel和Muhuk的回答)

from django import forms
from django.db.models.manager import Manager

# I used this instead of lambda expression after scope problems
def _get_cleaner(form, field):
    def clean_field():
         value = getattr(form.instance, field, None)
         if issubclass(type(value), Manager):
             value = value.all()
         return value
    return clean_field

class ROFormMixin(forms.BaseForm):
    def __init__(self, *args, **kwargs):
        super(ROFormMixin, self).__init__(*args, **kwargs)
        if hasattr(self, "read_only"):
            if self.instance and self.instance.pk:
                for field in self.read_only:
                    self.fields[field].widget.attrs['readonly'] = "readonly"
                    setattr(self, "clean_" + field, _get_cleaner(self, field))

# Basic usage
class TestForm(AModelForm, ROFormMixin):
    read_only = ('sku', 'an_other_field')

你可以优雅地在小部件中添加readonly:

class SurveyModaForm(forms.ModelForm):
    class Meta:
        model  = Survey
        fields = ['question_no']
        widgets = {
        'question_no':forms.NumberInput(attrs={'class':'form-control','readonly':True}),
        }

基于@paeduardo的回答(这是多余的),你可以在表单类初始化器中禁用一个字段:

class RecordForm(ModelForm):

     def __init__(self, *args, **kwargs):
            super().__init__(*args, **kwargs)
            var = self.fields['the_field']
            var.disabled = True

对于Django 1.2+,你可以像这样重写字段:

sku = forms.CharField(widget = forms.TextInput(attrs={'readonly':'readonly'}))