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()
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。
对于Admin版本，如果你有多个字段，我认为这是一个更紧凑的方式:
def get_readonly_fields(self, request, obj=None):
skips = ('sku', 'other_field')
fields = super(ItemAdmin, self).get_readonly_fields(request, obj)
if not obj:
return [field for field in fields if not field in skips]
return fields
另外两种(类似的)方法和一个通用的例子:
1)第一种方法-删除save()方法中的字段，例如(未测试;)):
def save(self, *args, **kwargs):
for fname in self.readonly_fields:
if fname in self.cleaned_data:
del self.cleaned_data[fname]
return super(<form-name>, self).save(*args,**kwargs)
2)第二种方法-在clean方法中将字段重置为初始值:
def clean_<fieldname>(self):
return self.initial[<fieldname>] # or getattr(self.instance, fieldname)
基于第二种方法，我将其概括为:
from functools import partial
class <Form-name>(...):
def __init__(self, ...):
...
super(<Form-name>, self).__init__(*args, **kwargs)
...
for i, (fname, field) in enumerate(self.fields.iteritems()):
if fname in self.readonly_fields:
field.widget.attrs['readonly'] = "readonly"
field.required = False
# set clean method to reset value back
clean_method_name = "clean_%s" % fname
assert clean_method_name not in dir(self)
setattr(self, clean_method_name, partial(self._clean_for_readonly_field, fname=fname))
def _clean_for_readonly_field(self, fname):
""" will reset value to initial - nothing will be changed
needs to be added dynamically - partial, see init_fields
"""
return self.initial[fname] # or getattr(self.instance, fieldname)
