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

一个简单的选择是在模板中输入form.instance.fieldName而不是form.fieldName。

其他回答

如果您需要多个只读字段。您可以使用下面给出的任何方法

方法1

class ItemForm(ModelForm):
    readonly = ('sku',)

    def __init__(self, *arg, **kwrg):
        super(ItemForm, self).__init__(*arg, **kwrg)
        for x in self.readonly:
            self.fields[x].widget.attrs['disabled'] = 'disabled'

    def clean(self):
        data = super(ItemForm, self).clean()
        for x in self.readonly:
            data[x] = getattr(self.instance, x)
        return data

方法2

继承的方法

class AdvancedModelForm(ModelForm):


    def __init__(self, *arg, **kwrg):
        super(AdvancedModelForm, self).__init__(*arg, **kwrg)
        if hasattr(self, 'readonly'):
            for x in self.readonly:
                self.fields[x].widget.attrs['disabled'] = 'disabled'

    def clean(self):
        data = super(AdvancedModelForm, self).clean()
        if hasattr(self, 'readonly'):
            for x in self.readonly:
                data[x] = getattr(self.instance, x)
        return data


class ItemForm(AdvancedModelForm):
    readonly = ('sku',)

基于yamiack的回答,我找到了一个更好的、非常简单的解决方案,它也可以处理ModelMultipleChoiceField字段。

从表单中删除字段。Cleaned_data禁止保存字段:

class ReadOnlyFieldsMixin(object):
    readonly_fields = ()

    def __init__(self, *args, **kwargs):
        super(ReadOnlyFieldsMixin, self).__init__(*args, **kwargs)
        for field in (field for name, field in self.fields.iteritems() if
                      name in self.readonly_fields):
            field.widget.attrs['disabled'] = 'true'
            field.required = False

    def clean(self):
        for f in self.readonly_fields:
            self.cleaned_data.pop(f, None)
        return super(ReadOnlyFieldsMixin, self).clean()

用法:

class MyFormWithReadOnlyFields(ReadOnlyFieldsMixin, MyForm):
    readonly_fields = ('field1', 'field2', 'fieldx')

这是最简单的方法吗?

在视图代码中是这样的:

def resume_edit(request, r_id):
    .....    
    r = Resume.get.object(pk=r_id)
    resume = ResumeModelForm(instance=r)
    .....
    resume.fields['email'].widget.attrs['readonly'] = True 
    .....
    return render(request, 'resumes/resume.html', context)

它工作得很好!

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。

沃克的回答对我帮助很大!

我用get_readonly_fields修改了他的例子,让它在Django 1.3中工作。

通常你应该在app/admin.py中声明这样的东西:

class ItemAdmin(admin.ModelAdmin):
    ...
    readonly_fields = ('url',)

我是这样适应的:

# In the admin.py file
class ItemAdmin(admin.ModelAdmin):
    ...
    def get_readonly_fields(self, request, obj=None):
        if obj:
            return ['url']
        else:
            return []

它工作得很好。现在,如果您添加一个Item, url字段是读写的,但在更改时它变成只读的。